Heterojunctions Derived by Integrating Arylene-Ethynylene Nanobelts

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Heterojunctions Derived by Integrating Arylene-Ethynylene Nanobelts and N-Doped Graphene for Molecular Sensing Juanjuan Gao, Yuliang Shen, Jingkun Fang, Weiqing Zhu, Xuezhen Lin, Haiou Song, Shupeng Zhang, and Xin Wang ACS Appl. Nano Mater., Just Accepted Manuscript • DOI: 10.1021/acsanm.9b00227 • Publication Date (Web): 18 Mar 2019 Downloaded from http://pubs.acs.org on March 21, 2019

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ACS Applied Nano Materials

Heterojunctions Derived by Integrating Arylene-Ethynylene Nanobelts and N-Doped Graphene for Molecular Sensing

Juanjuan Gao †, ‡, Yuliang Shen ‡, Jingkun Fang ‡, Weiqing Zhu ‡, Xuezhen Lin ‡, Haiou Song *, §, Shupeng Zhang *, †, ‡, ‖, Xin Wang *, †, ‡

†

Key Laboratory for Soft Chemistry and Functional Materials, Ministry of Education, Nanjing, 210094,

PR China ‡

School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, PR

China § School

‖

of Environment, Nanjing Normal University, Nanjing, 210097, PR China

Nanjing University & Yancheng Academy of Environmental Protection Technology and Engineering,

Yancheng 210009, P.R. China

*

Corresponding authors.

Tel/Fax: +86 25 84315519 E-mail address: [email protected] (H.O. Song) [email protected] (S.P. Zhang) [email protected] (X. Wang)

ACS Paragon Plus Environment

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ABSTRACT

Self-assembled

crystalline

nanobelts

were

fabricated

from

the

organically

synthesized

4,4'-(((anthracene-9,10-diylbis(ethyne-2,1-diyl))bis(2,5-bis(3,7-dimethyloctyl)-4,1-phenylene))bis(ethyne -2,1-diyl))bis(N,N-diphenylaniline) molecule (AE) by utilizing typical Sonogashira coupling reactions. One dimensional AE with high carrier transportability could be directly integrated with two dimensional N-doped graphene (NG), and the electrocatalytic performance was significantly affected by the rational coupling sensing platform (AE-NG). Further combination of beta-cyclodextrins (CD) with AE-NG could promote the electrochemical signal enhancement of ternary nanocomposites (CD-AE-NG) because of synergetic effects of improved solubility, host-guest recognition, anisotropic charge carrier mobility, conductivity, and electrocatalytic activity. The electrochemical sensor based on CD-AE-NG heterostructure

exhibited

good

electrochemical

responses

to

catechol

(CT),

aminophenols,

p-phenylenediamine, acetaminophen, tryptophan and tyrosine. CD-AE-NG modified electrode (CD-AE-NG/GCE), a representative example for detecting CT, achieved a broader linear range (0.05 400 μM) and lower detection limit of 0.026 μM (S/N = 3). Interestingly, the excellent simultaneous detection of APAP and Tyr could be obtained in the simulated body fluid. A detection limit of 0.120 and 0.322 μM (S/N = 3) was obtained for APAP and Tyr, respectively. The positive results show that hierarchical integration of nanobelts and NG has considerable potential in the fabrication of high-performance electrochemical devices.

2


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KEYWORDS: Arylene-ethynylene, nanobelt, heterojunction, N-doped graphene, electrochemical sensor, detection

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1. INTRODUCTION

One dimensional (1D) nanoarchitecture based on inorganic materials has drawn considerable attention because of its promising applications in various fields such as optoelectronics, catalysis, and energy storage.1-6 The development of organic synthetic chemistry further promotes its progress in this field.7 In contrast to inorganic materials, organic materials have the advantages of cost-effectiveness and easy molecular tailoring for performance optimization, as well as great flexibility and compatibility with self-assembly and physicochemical properties.8,

9

Functional organic nanomaterials with conductive

π-conjugated systems are expected to be good candidates for the next-generation electronic devices.10 It is possible that the self-assembly of organic molecules can improve the performance stability and carrier transportability,11-13 which would result more fascinating properties of good crystallinity and quantum size effect.9 Highly directional materials (e.g., 1D nanobelts) organized from organic molecules have drawn considerable attention because of their potential applications in the miniaturization of various optoelectronic devices such as sensors, light-emitting diodes, and photovoltaics, which are due to their high carrier transportability, perfect crystallinity, and well-defined geometry.14, 15 However, the amorphous organic materials with short-range order always have the problem of poor performance stability and low carrier transportability. High-quality manufacturing and geometric shape regulation of organic crystals around small molecule self-assembly could potentially help solve the problem and might cover a complementary range of electronics/photonics

4


11,

which is attributed to the

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high crystallinity resulting in the absence of grain boundaries and the resulting low defect density

12, 13.

Directional nanoscale self-assembly of molecular crystals revealed more fascinating properties of good crystallinity and quantum size effect.9 Therefore, the controlled self-assembly of 1D synthetic organic molecules remains a challenge. In many cases, the key step in forming a 1D structure is to control and optimize the strong entropy-stacking interactions between the anisometric aromatic disks and the hydrophobic interaction of the side chains. Fine structure control requires balancing two energy contributions, which limits the method of aromatic systems with appropriate aliphatic side chains.7 Great progress has been made in the preparation of nanobelts or nanowires from rigid, large, planar conjugate molecules, in which the π-π stacking of molecules predominantly follows the long-axis of the nanobelt or nanowire.12 The bottom-up approach can be an ideal alternative to arrangement of a large number of complex, small material units at low cost and in a less time-consuming way.9 For instance, the nanobelt structure of 6, 13-dichloropentacene were successfully fabricated through molecular arrangement of the strong face-to-face interaction between the adjacent planar cores.16 Oriented crystalline

micro-ribbons

of

9-anthracenecarboxylic

acid

were

self-assembled

through

a

solvent-evaporation method, and the micro-ribbons were found to twist reversibly under uniform illumination conditions.17 A photo-active anthracene derivative, dimethyl-2(3-(anthracen-9-yl)allylidene) malonate, was reported to be able to self-organize into single-crystal curling nanowires in a solvent-evaporation method.18 Arylene-ethynylene molecules with electron-rich π-surfaces are rigid linear planar molecular structures

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with several linearly fused benzene rings that favor the formation of 1D superstructure. They are used in the fluorescent and dye materials9 and optoelectronic devices.14 In this work, we discuss a photo-active anthracene derivative, 4, 4'-(((anthracene-9,10-diylbis(ethyne-2,1-diyl))bis(2,5-bis(3,7-dimethyloctyl)4,1-phenylene))bis(ethyne-2,1-diyl))bis(N,N-diphenylaniline) (AE), synthesized by typical Sonogashira coupling reactions. Its structure is shown in Scheme 1. AE exhibits a 1D nanobelt structure with a rich πconjugated system. The self-assembly of AE can be fabricated because of π-π interactions. In order to enhance the stability and carrier transportability, the prerequisite for forming the self-assembled AE nanostructures is balancing the strengths of the hydrophobic interaction of the side chains and the π-stacking interaction between the conjugation systems.7, 9 The substituted group of the branched long alkyl groups ((±)-3,7-dimethyloctyl) can delay the aggregation of π-systems, thus increasing the solubility of AE with ignorable alteration of the electronic properties.9,

19

An anthracene skeleton, four

carbon-carbon triple bonds and eight aromatic delocalizing electronic structures can generate a strong π-π conjugated effect, which can lead to efficient packing of AE in one-dimension.14, 20 Graphene, as a representative material for inorganic polymer two dimensional (2D) component possesses unique π-electron delocalization networks and intriguing 2D morphology

21,

which make it

highly useful as a solid material for adsorbing carrier molecules.20 In particular, the scientific introduction of heteroatom N atoms into graphene can be done to tailor the graphene electronic band structure22 and increase its electrocatalytic activity by generation of pyridine and quaternary nitrogen groups, etc. The lone pair of N atoms can conjugate with the unoxidized graphene region, forming a stable p-π system,23

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which can increase the n-type carrier density of the graphene region and can stimulate the anisotropic assembly. Therefore, the rationally integrating AE and N-doped graphene (NG) as a sensing platform may provide a promising heterojunction architechture for enhancing electrochemical performance. This synergistic combination of AE and NG can not only increase the structural and electronic variety,24 but also prevent their aggregation, thus effectively promoting formation of a unique there dimensional (3D) π-electron delocalization network and expose the more active sites of NG.25 The heterostructure can make it a highly useful solid material for adsorbing carrier molecules20 Furthermore, beta-cyclodextrin (CD) can be introduced to accommodate guest molecules because of supramolecular recognition.26 Therefore, delicately carefully designed CD-decorated AE-integrated NG sensing nanomaterial has good solubility, host-guest recognition, anisotropic charge carrier mobility, conductivity, and electrocatalytic activity;27, 28 these advantages are of significance in enhancing electrochemical performance.25, 29-31

Scheme 1

2. RESULTS AND DISCUSSION

Figure 1.

The sensing platform plays an important role in increasing the electrochemical performance. AE with a

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longer molecular chain exhibits an interesting 1D belt-like nanostructure (Figure 1A1). And AE stacks closely together because of the intermolecular π-π interaction from the conjugated systems of AE (Figure S2, A1 to D1).32, 33 The morphology of NG shows an exfoliated 2D nanostructure with wrinkled shapes (Figure 1A2, Figure S2, A2 and B2). NG TEM images at high magnification show the face-to-face nanostructure due to conjugated π systems (Figure S2, C2 and D2). The TEM image of AE-NG shows its coupled heterojunction nanostructure (Figure 1A3, Figure S2A3 to D3) in comparison to AE and NG. Conductive AE nanobelts were successfully incorporated into NG layers, which effectively prevented the aggregation of NG. This is a direct evidence that AE can be considered as a nanobridge that connects NG nanosheets. The increased interlayer spacing can absorb more CD molecules, acting as a recognition cavity that enhances the electrochemical performance. Most importantly, the rationally-designed 3D nanostructure can promote the exposure of more active sites because of N-doping into graphene.30 The precise structure of sensing materials is important for the scientific evaluation of electrochemical performance. The bonding nature and chemical structure of GO, AE, NG, AE-NG, CD-NG and CD-AE-NG were investigated by using FT-IR patterns (Figure 1B). The strong and broad absorption peak at 3337 cm-1 can be assigned to the O-H stretching vibration of GO (curve a).34 The peaks at 1728 and 1624 cm-1 of GO are ascribed to C=O in COOH and O-H bending vibrations, respectively.35 The peak located at 1048 cm-1 is due to C-O in alcoholic or epoxy groups (COH/COC).36 For NG (curve d), the characteristic adsorption peak for hydroxyl and carbonyl peaks were not observed; this means that these groups were removed during the N-doping treatment. In addition, the peak appearing at 1580 cm-1 is

8


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associated with deformation vibrations of C=N,37 which suggest the generation of nitrogenous heterocyclic structures. Moreover, we observed a broad peak at about 1096 cm-1, which is due to the formation of C-N bonds and the residual C-O groups.38 These changes indicate that nitrogen atoms were successfully incorporated into the graphene framework at low reaction temperature (80 °C). The FT-IR spectrum of AE exhibits two typical absorption peaks at 2924 and 2209 cm-1, which correspond to the C-H symmetrical stretching vibrations in CH2 and CH3 units and C≡C, respectively. The additional peaks appear at 1610, 1592, 1510 and 1494 cm-1 are attributed to vibrations of aromatic rings in the framework.39 In addition, the peaks at 834 and 695 cm-1 represent the substituted-benzene ring structure in AE (curve c). After self-assembly of AE and NG (curve e), several peaks appeared at 2920, 1585, 839, and 699 cm-1, demonstrating that AE nanobelts adsorbed onto the surface of NG. In particular, the disappearance of the peak at 2209 cm-1 due to C≡C groups shows that AE and the partially aromatic conjugation of restored NG have integrated because of the flow of the electron cloud with the aid of π-π interactions.40,

41

After CD introduction, both CD-NG and CD-AE-NG exhibited the typical CD

absorption features of the C-H/O-H bending vibrations at 1417 cm-1 and C-O-C groups at 1077 cm-1, which are related to NG. These observations clearly confirm that CD molecules have attached to the surfaces of NG and AE-NG.42 Similarly, the peak at 838 cm-1 due to the characteristic AE adsorption band can be also observed for CD-AE-NG (curve g). The hybrid heterojunction is confirmed by the generation of interfacial interactions. TGA was further used to evaluate the enhanced interfacial interactions. This was performed from 50 to

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800 °C at a heating rate of 10 °C min-1 in a N2 atmosphere. As shown in Figure 1C, GO exhibited an initial weight-loss below 200 °C due to the desorption of interlamellar water.43 The main weight loss then occurred within 200-500 °C, which is attributed to the decomposition of the oxygen-containing groups. As a temperature higher than 500 °C, the further weight loss is due to the decomposition of the more stable functional groups.39 Successful incorporation of N atoms into the graphene lattice resulted in additional π electrons conjugated with the C network, thereby increasing the delocalization ability and thermal stability.44 Compared with GO, AE exhibited higher thermal stability and began to decompose at about 300 °C. The combination of AE and NG enhanced the thermal stability of NG, which acted as connectors for AE because of formation of π-π interactions.43 It is noteworthy that the thermal stability of CD-NG is higher than that of NG at temperatures below 240 °C because of the formation of hydrogen bonds between CD and NG. When the temperature was further increased, the thermal stability of CD-NG become lower than that of NG.20 It is possible that the higher temperature accelerated the decomposition of CD. Most importantly, the incorporation of CD into NG layers resulted in increased water solubility of NG and enhanced the electrochemical selectivity and response. Similarly, the difference in thermal stability between AE-NG and CD-AE-NG also followed the rule mentioned above; the only turning point is 290 °C. As a result, CD-AE-NG was more thermally stable than was CD-NG, supporting that AE as a connector can strengthen construction. The structures and electronic properties of every material were further evaluated by using Raman spectra. In Figure 1D, two prominent scattering peaks at ∼1580 and ∼1350 cm−1 may be attributed to

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the radial C-C stretching vibrations of sp2 carbon pairs (G band) and induced six-fold aromatic ring breathing vibrations associated with the graphitic sp3 carbons or defects (D band), respectively.45 For the Raman spectra of GO, the apparent D band confirms that GO is multilayered and has many defects induced by the functional groups such as carboxyl and carbonyl introduced during the preparation; this benefits the doping with foreign atoms. Relative to that of GO, the ID/IG ratio of NG increased slightly because of the generation of smaller nanocrystalline graphene domains, the loss of carbon atoms resulting from the decomposition of oxygen-containing groups, and the incorporation of N heteroatoms.46 Compared with bare NG, the ID/IG ratio of CD-NG increased because introduction of CDs with sp3 defects. In particular, some new characteristic vibration peaks at 2171, 1478, 1281, 1018 and 389 cm-1 due to the AE can be observed from the Raman spectra of AE-NG and CD-AE-NG, these correspond to the C≡C stretching, C=C ring-stretching, N-R in-plane bending/-CH3 twisting, C-C stretching, C-C-C deformation mode of AE.47 The conclusions from FT-IR spectroscopy, TGA and Raman spectroscopy are consistent completely. These observations provide direct evidence that 1D AE were successfully functionalized onto the 2D graphene sheets through π-π interactions. The interfacial properties of surface-modified electrodes were investigated by EIS using 5.0 mM Fe(CN)63−/4− redox couple with 0.1 M KCl as a supporting electrolyte. The EIS profiles for bare GCE, GO/GCE, NG/GCE, AE/GCE, AE-NG/GCE, CD-NG/GCE and CD-AE-NG/GCE are depicted in Figure 1E. In general, the values of charge transfer resistances (Rct) of various electrodes were described by monitoring semicircle diameters of EIS at higher frequency, corresponding to the electron-transfer limited

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process associated with the ferricyanide ions.26, 48, 49 The corresponding Rct values are listed in Table S1. A notable decrease in Rct value was observed for NG/GCE relative to that of GO/GCE. This is explained by replacement of the electron-rich N into the C network, which improves the electrocatalytic performance and the π electron conjugated system, thereby increasing the conductivity and charge carrier density of graphene.44 The Rct value for AE/GCE shows a decrease, which illustrates the better conductivity of AE. On the other hand, AE-NG/GCE exhibited the smallest semicircle and lowest Rct value. It provided direct evidence that AE can be as conductive bridge that increases the electron transfer rate of AE-NG. The Rct value of CD-NG increased dramatically, indicating a difficult interfacial charge transfer caused by insulating CDs. It should be noted that the AE-NG is more suitable than is CD-NG because the strong conjugation effect could promote electron transfer more than the hydrogen bonding effect.20 Similarly, the resistance of CD-AE-NG/GCE slightly increased, albeit less than that of CD-NG/GCE. This result shows that the coupling of the AE connector and CD host-guest recognition can be designed for a sensing electrode for determining analytes.

Figure 2.

On the basis of the above discussion, CD-AE-NG heterojunction has large specific surface area, improved conductivity and higher anisotropic charge carrier mobility. Thus, CD-AE-NG/GCE can be utilized as an electrochemical sensor for detecting phenolic contaminants and biomolecules by

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constructing supramolecular complexes between the appropriate guest molecules and CD of the sensing platform. To investigate this assumption, the electrochemical behaviours were evaluated by examining six electroactive molecules including catechol (CT), aminophenols (AP), p-phenylenediamine (PPD), acetaminophen (APAP), tryptophan (Trp) and tyrosine (Tyr). The electrochemical performance was studied by differential pulse voltammetry (DPV) using bare GCE, GO/GCE, NG/GCE, AE-NG/GCE, CD-NG/GCE and CD-AE-NG/GCE in 0.1 M citrate-phosphate buffer (pH 4.0). As shown in Figure 2A-F, the peak currents of six analytes using the GO/GCE were markedly enhanced relative to that of the bare GCE, indicating that GO with the large specific surface area has favorable catalytic abilities for the oxidation of analytes. All of the peak currents on the NG/GCE for the investigated analytes also increased relative to that of GO/GCE, indicating that the increased conductivity and electrocatalytic activities of NG. In the case of AE-NG/GCE, every compound showed an increase in the peak current in relative to that of NG/GCE. The reasons are as follows: 1) Introduction of AE can effectively prevent the aggregation of NG nanosheets; 2) integration of AE into NG forms a complete π-conjugated system, promoting rapid electron transport and reducing electron loss during the electrochemical reactions; and 3) more catalytic active sites of NG become exposed outside, and so the analytes may easily approach them.20 In addition, in comparison with the oxidation peak currents at the NG/GCE, the CD-NG/GCE also showed higher response currents for all analytes, showing the supramolecular host-guest recognition and enrichment effect between CDs and the guests. Finally all of the peak currents of target analytes at CD-AE-NG/GCE showed the strongest electrochemical responses in relative to those at the other five electrodes. The

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synergistic effect of CD, AE, and NG plays an important role in enhancing electrochemical determination for several analytes. Besides the three reasons for AE mentioned above, the supramolecular recognition of CD and electrocatalytic core of NG with large specific surface area and high conductivity must not be ignored. AE-NG with expanded interlayer spacing can accommodate more CD molecules and expose more active sites of NG, which lead to the electrochemical response.48,

50

Overall, the unique 3D

heterostructure of CD-AE-NG has the potential for utilization as a sensing platform. The sensitivity and selectivity of CD-AE-NG are of significance for evaluating an electrochemical sensor. CT, an important organic chemical raw materials and intermediates, is widely applied in agriculture, dyes, spices, rubber, medicine, photographic materials and other fields. At the same time, it is a typical environmental pollutant that is toxic. It has a stimulating effect on the respiratory tract and can cause dermatitis by contact with the skin. Therefore, the accurate detection of CT is crucial for environmental regulation. Here, CT was chosen as a target analyte to investigate the sensing performance of CD-AE-NG/GCE using the DPV technique. Generally, the electrocatalytic properties of an as-prepared modified electrode are influenced by many factors. In order to optimize the experimental parameters, the relevant experimental parameters were studied.48

Figure 3.

The acidity of electrolytes on the detection platform is significant because its composition has a great

14


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influence on the thermodynamics and kinetics of the charge transfer at the electrode/solution interface.51 In this regard, the oxidation peak current and potential of CT at the CD-AE-NG/GCE was studied using DPV and in 0.1 M citrate-phosphate buffer at pH ranges of 3.0 to 7.0. As shown in Figure 3A, the maximum current signal of CT was observed at pH 4.0, and then decreased rapidly with further increase in pH. This phenomenon may be attributed to the following reasons. CT as a proton aromatic molecule tends to deprotonate into an anion at high pH and produces electrostatic repulsion with the electrode surface because of the electronegativity of the sensing material, which may lead to a decrease in the ability of the electrode surface to absorb the analyte.52 Hence, the corresponding DPV response decreases as the pH value continues to increase. Considering the sensitivity of the determination, we selected pH 4.0 for the optimal detection medium. As shown in Figure 3B, a negative shift was observed in the oxidation peak potential of CT with increasing pH value, suggesting that the entire electrochemical process of CT species was proton-dependent. In addition, the highly linear relationship between the oxidation peak potential and the corresponding pH value is described as follows: Ep = 0.709 − 0.0641pH (R = 0.999). The obtained slope is close to the Nernstian theoretical value of 59.1 mV, implying that the electrode reaction of CT is anticipated to accompanied by two-electron and two-proton transfer process.26, 53 The simple and effective strategy for enhancing the current response is the accumulation step. The effect of response time on the oxidation peak current for CT at 0 V at a stirring speed of 400 rpm was envaluated (Figure 3C). The current response of CT increased up to 40 s and then decreased gradually

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with longer accumulation time. This is attributed to the fast surface adsorption and the tendency of the amount of CT at the CD-AE-NG electrode surface to be saturated.54 The relationship between the oxidation peak current of CT and accumulation potential ranging from − 0.2 to 0.2 V at 40 s at a stirring speed of 400 rpm was also investigated. It can be seen from Figure 3D that the optimum accumulation potential was 0 V. Considering both working efficiency and sensitivity, we therefore selected an accumulation step at 0 V for 40 s. On the basis of the above discussions, the superior sensitivity of our developed electrochemical sensor could be investigated by DPV under the optimized experimental conditions. The response currents of CD-AE-NG/GCE increased with increasing CT concentration (Figure 3E). A good linear relationship was obtained in the concentration range of 0.05 - 25 μM and 25 - 400 μM with good reproducibility of measurements (Figure 3F). The corresponding constructed calibration curves could be Ip,CT1 = 0.491 CCT + 21.453 (R = 0.9998) and Ip,CT2 = 0.065 CCT + 32.424 (R = 0.9994). The detection limit was calculated to be 0.026 μM at the S/N = 3. Interestingly, there are two linear relationships within the detection concentration range, probably because of the heterogeneous multilayer enrichment process of heterojunction with limited surface active sites. The analyte preferentially occupies the sites of high energy activity on the CD-AE-NG during accumulation. Subsequently, more analytes would slowly condense at other active sites with low energy until reaching dynamic equilibrium due to the saturation of high-energy active sites is reached. Thus, the slope of calibration curve 1 is greater than the slope of curve 2.20 A comparison of CD-AE-NG/GCE with other reported sensors for CT detection is indicated in Table

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S2. The good liner relationship and lower detection limit indicated the excellent electrochemical performance of CD-AE-NG/GCE. Rational integration of CD-AE-NG could enhance the detection sensitivity. The sensitivity and selectivity of CD-AE-NG/GCE can be studied by the anti-interference experiments. The possible interferents mainly come from other coexisting phenolic pollutants (e.g., resorcinol, hydroquinone, p-nitrophenol, p-aminophenol, and o-phenylenediamine), which may cause changes in the existing peak potential and current. As shown in Figure S3, the presence of interfering samples in the system had no significant effect on the DPV response of CT. In addition, the interferences of some inorganic ions (e.g., Cu2+, Ca2+, Zn2+, Mg2+, K+, NO3-, Br-, SO42-, NO3-, and Cl-) on CD-AE-NG/GCE were studied with the i-t curve. As shown in Figure S4, the 100-fold concentrations of these interfering species had no influence on the current response of CT, indicating that CD-AE-NG/GCE has good interference tolerance. The practical feasibility of CD-AE-NG/GCE was validated by detecting CT in Nanjing River water. The standard addition method was used to analyze CT by measuring the sample for three times. The results along and the recoveries obtained by spiking CT with the samples are shown in Table 1. The analytical results obtained by DPV are consistent with both the actual addition amount and UV–vis spectrophotometry. In addition, recoveries of about 100% were achieved for of all the spiked samples. This means that the proposed sensor was sensitive enough and very reliable for the determination of CT in practical application.

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Table 1

To further validate the practical feasibility of CD-AE-NG/GCE, we also studied the simultaneous detection of APAP and Tyr. They are considered as endocrine disruptors, and usually coexist in the human body. APAP is a fever-reducing medication, and a metabolite of phenacetin, which can regulate central prostaglandin synthetase by inhibiting hypothalamic body temperature. Excessive dose can cause liver damage, and severe cases can cause coma or even death. As an amino acid nutrient and a drug substance, Tyr is an aromatic polar α-amino acid containing a phenolic hydroxyl groups, and also a conditional essential amino acid and a ketogenic glycogenic amino acid in the human body, which has a stimulating and antidepressant effect. Recent studies have confirmed that APAP reduces the effect of captopril by opposing the effect of drugs. It has been found that after being subjected to toxic doses of APAP, nitrated Tyr residues and APAP adducts can be found in necrotic cells.55 In view of this, the development of high-performance electrochemical sensors for simultaneous determination of APAP and Tyr is of great value for the analysis of practical samples.56 We used 0.1 M phosphate buffer solutions (PBS, pH 7.4) containing 20% human serum to simulate human body fluid as a detection medium. First, we employed all obtained electrodes to test the electrochemical performance for simultaneous detection of APAP and Tyr by DPV. As shown in Figure 4, the CD-AE-NG/GCE showed the strongest electrochemical responses and smallest potentials in relative to the other five electrodes, and two

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well-defined and fully resolved anodic peaks were achieved successfully corresponding to APAP and Tyr. This observation indicates that the unique 3D heterostructure of CD-AE-NG has the potential in practice.

Figure. 4.

The electrochemical performance of the CD-AE-NG/GCE was furthermore investigated by using DPV for the simultaneous sensing of APAP and Tyr with the concentration range from 0.5 to 1000 μM. As shown in Figure 5A, the simultaneous determination of APAP and Tyr in the mixed solution was performed by simultaneously increasing the concentration of APAP and Tyr. The oxidation peak currents of APAP and Tyr increase with the increase of their concentrations, respectively. The results are shown in Figure 5B, and a good linear relationship was obtained in the concentration range of 0.5 - 100 μM and 100 - 1000 μM. The linear regression equations could be described as Ip, APAP1 = 0.022 CAPAP + 1.118 (R = 0.999), Ip, APAP2 = 0.011 CAPAP + 2.448 (R = 0.999), and Ip, Tyr1 = 0.008 CTyr + 0.721 (R = 0.999), Ip, Tyr 2 = 0.004 CTyr + 1.306 (R = 0.994). A detection limit of 0.120 and 0.322 μM (S/N = 3) was obtained for APAP and Tyr, respectively. A comparison of CD-AE-NG/GCE with other reported sensors for APAP and Tyr detection is indicated in Table S3. The above results demonstrated that the proposed CD-AE-NG/GCE sensor exhibited excellent analytical performances for APAP and Tyr with a lower detection limit, which revealed that the CD-AE-NG/GCE could be considered as a sensitive and selective electrochemical sensor to achieve the simultaneous sensing of APAP and Tyr.

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Figure 5.

3. CONCLUSIONS

In summary, we have designed and synthesized an anthracene derivative for self-assemble into oriented crystalline nanobelts via a bottom-up solvent-evaporation approach. The availability of 1D AE would directly translate into the possibility of integrating 2D NG into assembled heterojunction architecture in order to enhance unique 3D π-electron delocalization network formation and expose the more active sites of NG. CD-decorated AE-integrated NG hierarchical structures to endow the sensing nanomaterial with improved solubility, host-guest recognition, anisotropic charge carrier mobility, conductivity and electrocatalytic activity was carefully designed. All of these play a key role in improving the sensing response of analyte detection and thus provide technical support for constructing electrochemical sensor to achieve ultra-sensitive detection of CT. Overall, the considerable integration possibility presented by the heterostructures shows great promise for this area in both applied technologies and basic studies.

4. EXPERIMENTAL

Construction of CD-AE-NG composite. CD-AE-NG was prepared by two-step hydrothermal method (Scheme 1). The detailed synthesis methods of 1D AE are provided in the Supporting Information. The

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precursor GO was synthesized from graphite by an improved Hummers’ method.57, 58 GO (10 mg) and AE (5 μmoL) were mixed and sonicated in DMF to form a stable suspension. The dispersion was then transferred to a reaction vial with addition of 500 μL of ammonia and treated at 80 °C for 2 days to enable the complete assembly of AE on the surface of GO sheets and nitrogen doping. The chemical structure of NG is shown in Figure S1. The product (AE-NG) was collected after centrifugation, followed by sonicating in DMF solution mixed with 320 mg of CD. The homogeneous AE-NG and CD dispersion was then transferred to a reaction vial treated at 80 °C for 2 days. The product (CD-AE-NG) was then obtained after washing and drying. Fabrication of the sensor. To prepare the CD-AE-NG-modified electrodes, 2.0 mg of CD-AE-NG composite was dispersed in 2 mL of water/Nafion (5%) (1 : 9, v/v) solvent mixture, which was then sonicated for 2 h to enhance the tackiness and sensitivity of the modified electrodes. Subsequently, 5 μL of the suspension was drawn and pipetted onto the pre-cleaned GCE and dried in air. This was followed by gently rinsing for several times with doubly distilled water to remove loosely attached CD-AE-NG before measurements. The modified electrodes of the other modified materials (GO, AE, NG, AE-NG and CD-NG) prepared for the comparison is consistent with the above.

ASSOCIATED CONTENT Supporting Information The Supporting Information is available free of charge on the ACS Publications website at DOI:

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More details of materials, experimental procedures, instrumentation, TEM images of AE, NG and AE-NG at different magnifications, charge transfer resistance for the different electrodes, comparison of the proposed sensor for CT detection with other reported electrodes, comparison of the proposed sensor for CT detection with other reported electrodes, DPV oxidation currents and amperometric response of CD-AE-NG/GCE (PDF).

AUTHOR INFORMATION Corresonding Authors *E-mail: [email protected] (S.P. Zhang) [email protected] (H.O. Song) [email protected] (X. Wang) ORCID Juanjuan Gao: 0000-0003-2557-5022 Yuliang Shen: 0000-0003-3707-0275 Jingkun Fang: 0000-0003-2606-2640 Weiqing Zhu: 0000-0003-4501-6543 Xuezhen Lin: 0000-0002-5794-3910

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Haiou Song: 0000-0003-1346-8131 Shupeng Zhang: 0000-0001-6478-1537 Xin Wang: 0000-0003-4099-4268 Notes The authors declare no competing ﬁnancial interest.

ACKNOWLEDGMENTS

This work was supported by the Natural Science Foundation of China (51402151, 51408297, 51778281); the Natural Science Foundation of the Jiangsu province (BK20171342, BK20161493, BK20140780); the QingLan Project, PAPD, Jiangsu Province; and the Zijin Intelligent Program, the Nanjing University of Science and Technology; Fundamental Research Funds for the Central Universities (30917011309), the Nanjing Normal University Research Funding (184080H202B146). The authors also acknowledge appreciation to the Institute of Water Environmental Engineering, Jiangsu Industrial Technology Research Institute (Yancheng) for their helpful support (NDYCKF201703).

REFERENCES

23



(1)

Page 24 of 42

Cheng, F.; Su, Y.; Liang, J.; Tao, Z.; Chen, J. MnO2-Based Nanostructures as Catalysts for

Electrochemical Oxygen Reduction in Alkaline Media. Chem. Mater. 2014, 22, 898–905. (2)

Wu, H.; Hu, L.; Rowell, M. W.; Kong, D.; Cha, J. J.; Mcdonough, J. R.; Zhu, J.; Yang, Y.;

Mcgehee, M. D.; Cui, Y. Electrospun metal nanofiber webs as high-performance transparent electrode. Nano Lett. 2010, 10, 4242–4248. (3)

Hui, W.; Yi, C. Designing nanostructured Si anodes for high energy lithium ion batteries. Nano

Today 2012, 7, 414–429. (4)

Fard, M. J. S.; Morsali, A. Sonochemical Synthesis of New Nano-Belt One-Dimensional

Double-Chain Lead(II) Coordination Polymer; As Precursor for Preparation of PbBr(OH) Nano-Structure. J. Inorg. Organomet. Polym Mater. 2010, 20, 727–732. (5) Shape

Song, X.; Zhang, Z.; Zhang, S. F.; Wei, J.; Ye, K.; Liu, Y.; Marder, T. B.; Wang, Y. Geometric Regulation

and

Non-Covalent

Synthesis

of

One-Dimensional

Organic

Luminescent

Nano/Micro-Materials. J. Phys. Chem. Lett. 2017, 8, 3711–3717. (6)

Li, L.; Fan, H.; Hou, C.; Zhang, Q.; Li, Y.; Yu, H.; Wang, H. Highly Aligned Molybdenum

Trioxide Nanobelts for Flexible Thin-Film Transistors and Supercapacitors: Macroscopic Assembly and Anisotropic Electrical Properties. ACS Appl. Nano Mater. 2019. (7)

Huang, M.; Schilde, U.; Kumke, M.; Antonietti, M.; Cölfen, H. Polymer-Induced Self-Assembly

of Small Organic Molecules into Ultralong Microbelts with Electronic Conductivity. J. Am. Chem. Soc. 2010, 132, 3700–3707.

24


Page 25 of 42 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

(8)


Kim, F. S.; Ren, G.; Jenekhe, S. A. One-Dimensional Nanostructures of π-Conjugated Molecular

Systems: Assembly, Properties, and Applications from Photovoltaics, Sensors, and Nanophotonics to Nanoelectronics. Chem. Mater. 2011, 23, 622–629. (9)

Guo, Y.; Xu, L.; Liu, H.; Li, Y.; Che, C. M.; Li, Y. Self-assembly of functional molecules into

1D crystalline nanostructures. Adv. Mater. 2015, 27, 985–1013. (10) Zhan, X.; Facchetti, A.; Barlow, S.; Marks, T. J.; Ratner, M. A.; Wasielewski, M. R.; Marder, S. R. Rylene and Related Diimides for Organic Electronics. Adv. Mater. 2011, 23, 268–284. (11) Diao, Y.; Tee, B. C.; Giri, G.; Xu, J.; Kim, d. H.; Becerril, H. A.; Stoltenberg, R. M.; Lee, T. H.; Xue, G.; Mannsfeld, S. C. Solution coating of large-area organic semiconductor thin films with aligned single-crystalline domains. Nat. Mater. 2013, 12, 665–671. (12) Che Y.; Datar A.; Yang X. M.; Naddo T.; Zhao J. C.; Zang, L. Enhancing One-Dimensional Charge Transport through Intermolecular π-Electron Delocalization: Conductivity Improvement for Organic Nanobelts. J. Am. Chem. Soc. 2007, 129, 6354–6355. (13) Li, H.; Tee, B. C.; Cha, J. J.; Cui, Y.; Chung, J. W.; Sang, Y. L.; Bao, Z. High-Mobility Field-Effect Transistors from Large-Area Solution-Grown Aligned C60 Single Crystals. J. Am. Chem. Soc. 2012, 134, 2760–2765. (14) Datar A.; Balakrishnan K.; Yang X.; Zuo X. B.; Huang J .L.; Oitker R.; Yen M.; Zhao J. C.; Tiede D. M.; Zang L. Linearly polarized emission of an organic semiconductor nanobelt. J. Phys. Chem. B 2006, 110, 12327–32.

25



Page 26 of 42

(15) Chen, S.; Slattum, P.; Wang, C.; Zang, L. Self-Assembly of Perylene Imide Molecules into 1D Nanostructures: Methods, Morphologies, and Applications. Chem. Rev. 2015, 115, 11967–11998. (16) Wang, M.; Gong, Y.; Alzina, F.; Svoboda, O.; Ballesteros, B.; Sotomayor, C. T.; Xiao, S.; Zhang, Z.; He, J. Raman antenna effect from exciton-phonon coupling in organic semiconducting nanobelts. Nanoscale 2017, 9, 19328–19336. (17) Zhu, L.; Alkaysi, R. O.; Bardeen, C. J. Reversible Photoinduced Twisting of Molecular Crystal Microribbons. J. Am. Chem. Soc. 2011, 133, 12569–12575. (18) Kim, T.; Almuhanna, M. K.; Alsuwaidan, S. D.; Alkaysi, R. O.; Bardeen, C. J. Photoinduced curling of organic molecular crystal nanowires. Angew. Chem. Int. Ed. 2013, 125, 6889–6893. (19) Yang, X.; Fang, J.-K.; Suzuma, Y.; Xu, F.; Orita, A.; Otera, J.; Kajiyama, S.; Koumura, N.; Hara, K. Synthesis and Properties of 9,10-Anthrylene-substituted Phenyleneethynylene Dyes for Dye-sensitized Solar Cell. Chem. Lett. 2011, 40, 620–622. (20) Gao, J.; Fang, J.; Ju, X.; Zhu, W.; Lin, X.; Zhang, S.; Ma, C.; Song, H. Hierarchical Self-Assembly of Cyclodextrin and Dimethylamino-Substituted Arylene-Ethynylene on N-doped Graphene for Synergistically Enhanced Electrochemical Sensing of Dihydroxybenzene Isomers. ACS Appl. Mater. Interfaces 2017, 9, 38802–38813. (21) Weng, S. X.; Yousefi, N.; Tufenkji, N. Self-Assembly of Ultralarge Graphene Oxide Nanosheets and Alginate into Layered Nanocomposites for Robust Packaging Materials. ACS Appl. Nano Mater. 2019.

26


Page 27 of 42 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(22) Du, X.; Zhou, C.; Liu, H.-Y.; Mai, Y.-W.; Wang, G. Facile chemical synthesis of nitrogen-doped graphene sheets and their electrochemical capacitance. J. Power Sources 2013, 241, 460–466. (23) Liu, X.; Li, L.; Meng, C.; Han, Y. Palladium Nanoparticles/Defective Graphene Composites as Oxygen Reduction Electrocatalysts: A First-Principles Study. J. Phys. Chem. C 2012, 116, 2710–2719. (24) Jariwala, D. Mixed Dimensional Van der Waals Heterostructures for Opto-Electronics. Nat. Mater. 2017, 16, 170–181. (25) Yan, L.; Zheng, Y. B.; Zhao, F.; Li, S.; Gao, X.; Xu, B.; Weiss, P. S.; Zhao, Y. Chemistry and physics of a single atomic layer: strategies and challenges for functionalization of graphene and graphene-based materials. Chem. Soc. Rev. 2012, 41, 97–114. (26) Gao, J.; Liu, M.; Song, H.; Zhang, S.; Qian, Y.; Li, A. Highly-sensitive electrocatalytic determination for toxic phenols based on coupled cMWCNT/cyclodextrin edge-functionalized graphene composite. J. Hazard. Mater. 2016, 318, 99–108. (27) Zalake, P.; Ghosh, S.; Narasimhan, S.; Thomas, K. G. Descriptor-based Rational Design of Two-dimensional Self-assembled Nano-architectures Stabilized by Hydrogen Bonds. Chem. Mater. 2017, 29, 7170–7182. (28) Jing, B.; Chen, X.; Zhao, Y.; Wang, X.; Cai, J.; Qiu, H. Ionic Self-Assembled Organic Nanobelts from The Hexagonal Phase Complexes and Their Cyclodextrin Inclusions. J. Phys. Chem. B 2008, 112, 7191–7195. (29) Xu, J.; Li, X.; Liu, J.; Wang, X.; Peng, Q.; Li, Y. Solution route to inorganic

27



Page 28 of 42

nanobelt‐conducting organic polymer core‐shell nanocomposites. J. Polym. Sci., Part A: Polym. Chem. 2010, 43, 2892–2900. (30) Gao, J.; Zhang, S.; Liu, M.; Tai, Y.; Song, X.; Qian, Y.; Song, H. Synergistic combination of cyclodextrin edge-functionalized graphene and multiwall carbon nanotubes as conductive bridges toward enhanced sensing response of supramolecular recognition. Electrochim. Acta 2016, 187, 364–374. (31) Bai, W.; Jiang, Z.; Ribbe, A. E.; Thayumanavan, S. Smart Organic Two-Dimensional Materials Based on a Rational Combination of Non-covalent Interactions. Angew. Chem. Int. Ed. 2016, 55, 10707–10711. (32) Liu, S. Z.; Wu, X.; Zhang, A. Q.; Qiu, J. J.; Liu, C. M. 1D Nano- and Microbelts Self-Assembled from the Organic-Inorganic Hybrid Molecules: Oxadiazole-Containing Cyclotriphosphazene. Langmuir 2011, 27, 3982–3990. (33) Urbanová, V.; Bakandritsos, A.; Jakubec, P.; Szambó, T.; Zbořil, R. A facile graphene oxide based sensor for electrochemical detection of neonicotinoids. Biosens. Bioelectron. 2016, 89, 532–537. (34) Zhu, J.; Chen, S.; Zhou, H.; Wang, X. Fabrication of a low defect density graphene-nickel hydroxide nanosheet hybrid with enhanced electrochemical performance. Nano Res. 2012, 5, 11–19. (35) Zhang, S.; Xiong, P.; Yang, X.; Wang, X. Novel PEG functionalized graphene nanosheets: enhancement of dispersibility and thermal stability. Nanoscale 2011, 3, 2169–2174. (36) Gao, J.; Zhang, S.; Zhang, X.; Yu, C.; Ye, H.; Qian, Y.; Song, H. Chemically edge-connected multilayer graphene-based architecture with enhanced thermal stability and dispersibility: experimental

28


Page 29 of 42 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


evidence of making the impossible possible. RSC Adv. 2015, 5, 3954–3958. (37) Wang, L.; Yin, F.; Yao, C. N-doped graphene as a bifunctional electrocatalyst for oxygen reduction and oxygen evolution reactions in an alkaline electrolyte. International J. Hydrogen Energy 2014, 39, 15913–15919. (38) Lin, Z.; Waller, G.; Liu, Y.; Liu, M.; Wong, C.-P. Facile Synthesis of Nitrogen-Doped Graphene via Pyrolysis of Graphene Oxide and Urea, and its Electrocatalytic Activity toward the Oxygen-Reduction Reaction. Adv. Energy Mater. 2012, 2, 884–888. (39) Tu, J.; Zhao, M.; Zhan, X.; Ruan, Z.; Zhang, H. L.; Li, Q.; Li, Z. Functionalization of graphene by a TPE-containing polymer using nitrogen-based nucleophiles. Polym. Chem. 2016, 7, 4054–4062. (40) Xu, Y.; Zhao, L.; Bai, H.; Hong, W.; Li, C.; Shi, G. Chemically Converted Graphene Induced Molecular Flattening of 5,10,15,20-Tetrakis(1-methyl-4-pyridinio)porphyrin and Its Application for Optical Detection of Cadmium(II) Ions. J. Am. Chem. Soc. 2009, 131, 13490–13497. (41) Patel, M.; Feng, W.; Savaram, K.; Khoshi, M. R.; Huang, R.; Sun, J.; Rabie, E.; Flach, C.; Mendelsohn, R.; Garfunkel, E. Graphene: Microwave Enabled One-Pot, One-Step Fabrication and Nitrogen Doping of Holey Graphene Oxide for Catalytic Applications. Small 2015, 11, 3358–3368. (42) Guo, Y.; Guo, S.; Ren, J.; Zhai, Y.; Dong, S.; Wang, E. Cyclodextrin Functionalized Graphene Nanosheets with High Supramolecular Recognition Capability: Synthesis and Host-Guest Inclusion for Enhanced Electrochemical Performance. ACS Nano 2010, 4, 4001–4010. (43) Cao, K.; Tian, Y.; Zhang, Y.; Yang, X.; Bai, C.; Luo, Y.; Zhao, X.; Ma, L.; Li, S. Strategy and

29



Page 30 of 42

mechanism for controlling the direction of defect evolution in graphene: preparation of high quality defect healed and hierarchically porous graphene. Nanoscale 2014, 6, 13518–13526. (44) Luo, Z.; Lim, S.; Tian, Z.; Shang, J.; Lai, L.; MacDonald, B.; Fu, C.; Shen, Z.; Yu, T.; Lin, J. Pyridinic N doped graphene: synthesis, electronic structure, and electrocatalytic property. J. Mater. Chem. 2011, 21, 8038–8044. (45) Rajkumar, C.; Veerakumar, P.; Chen, S. M.; Thirumalraj, B.; Liu, S. B. Facile and novel synthesis of palladium nanoparticles supported on a carbon aerogel for ultrasensitive electrochemical sensing of biomolecules. Nanoscale 2017, 9, 6486–6496. (46) Zhan, Y.; Huang, J.; Lin, Z.; Yu, X.; Zeng, D.; Zhang, X.; Xie, F.; Zhang, W.; Chen, J.; Meng, H. Iodine/nitrogen co-doped graphene as metal free catalyst for oxygen reduction reaction. Carbon 2015, 95, 930–939. (47) Ouyang, C.; Qian, X.; Wang, K.; Liu, H. Controllable one-dimension nanostructures of CuTNAP for field emission properties. Dalton Trans. 2012, 41, 14391–14396. (48) Jian, Z.; Xi, L.; Linlin, Y.; Songlin, Y.; Mengmeng, W.; Dan, C.; Qi, C.; Yulin, D.; Peng, L.; Weiquan, C. The Cu-MOF-199/single-walled carbon nanotubes modified electrode for simultaneous determination of hydroquinone and catechol with extended linear ranges and lower detection limits. Anal. Chim. Acta 2015, 899, 57–65. (49) Liu, L.; Ma, Z.; Zhu, X.; Zeng, R.; Tie, S.; Nan, J. Electrochemical behavior and simultaneous determination of catechol, resorcinol, and hydroquinone using thermally reduced carbon nano-fragment

30


Page 31 of 42 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


modified glassy carbon electrode. Anal. Methods 2015, 8, 605–613. (50) Liu, N.; Ma, Z. Au-ionic liquid functionalized reduced graphene oxide immunosensing platform for simultaneous electrochemical detection of multiple analytes. Biosens. Bioelectron. 2014, 51, 184–190. (51) PeterT Laboratory techniques in electroanalytical chemistry. Dekker 1984. (52) Astudillo, P. D.; Tiburcio, J.; González, F. J. The role of acids and bases on the electrochemical oxidation of hydroquinone: Hydrogen bonding interactions in acetonitrile. J. Electroanal. Chem. 2007, 604, 57–64. (53) Ribeiro, G. H.; Vilarinho, L. M.; Ramos, T. D. S.; Bogado, A. L.; Dinelli, L. R. Electrochemical behavior of hydroquinone and catechol at glassy carbon electrode modified by electropolymerization of tetraruthenated oxovanadium porphyrin. Electrochim. Acta 2015, 176, 394–401. (54) Wang, Y.; Wang, L.; Huang, W.; Zhang, T.; Hu, X.; Perman, J. A.; Ma, S. A metal-organic framework and conducting polymer based electrochemical sensor for high performance cadmium ion detection. J. Mater. Chem. A 2017, 5, 8385–8393. (55) James, L. P.; Mayeux, P. R.; Hinson, J. A. Acetaminophen-induced hepatotoxicity. Drug Metab. Dispos. 2003, 31, 1499–1506. (56) Karimi-Maleh, H.; Ganjali, M. R.; Norouzi, P.; Bananezhad, A. Amplified nanostructure electrochemical sensor for simultaneous determination of captopril, acetaminophen, tyrosine and hydrochlorothiazide. Mater. Sci. Eng., C 2017, 73, 472–477. (57) Hummers, W. S.; Offeman, R. E. Preparation of Graphitic Oxide. J. Am. Chem. Soc. 1958, 80,

31



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1339–1339. (58) Kovtyukhova, N. I.; Ollivier, P. J.; Martin, B. R.; Mallouk, T. E.; Chizhik, S. A.; Buzaneva, E. V.; Gorchinskiy, A. D. Layer-by-Layer Assembly of Ultrathin Composite Films from Micron-Sized Graphite Oxide Sheets and Polycations. Chem. Mater. 1999, 11, 771–778.

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Captions Scheme 1 Illustration of the procedures for fabricating CD-AE-NG. Figure 1. TEM images of AE (A1), NG (A2) and AE-NG (A3); FT-IR spectra (B), TGA (C), Raman spectra (D) of GO, CDs, AE, NG, AE-NG, CD-NG and CD-AE-NG hybrids; Nyquist plots (E) at the bare GCE (a), GO/GCE (b), NG/GCE (c), AE-NG (d), CD-NG (e) and CD-AE-NG (f) in 5.0 mM Fe(CN)63−/4− containing 0.1 M KCl solution. Figure 2. DPVs obtained for the oxidation of 0.1 mM CT (A), AP (B), PPD (C), APAP (D), Trp (E) and Tyr (F) at bare GCE (a), GO/GCE (b), NG/GCE (c), AE-NG/GCE (d), CD-NG/GCE (e) and CD-AE-NG/GCE (f) in 0.1 M pH 4.0 citrate-phosphate buffer. Pulse width: 0.05s; amplitude: 0.05V. Figure 3. (A) Effect of detection medium pH on the anodic peak currents of 0.5 mM of CT at CD-AE-NG/GCE in 0.1 M citrate-phosphate buffer; (B) The plots of anodic peak potential of CT versus pH values. (C) Effect of accumulation time on the oxidation peak currents of 0.1 mM CT at CD-AE-NG/GCE in 0.1 M pH 4.0 citrate-phosphate buffer by DPV; Stirring speed: 400 rpm. (D) Effect of accumulation potential on the oxidation peak currents of 0.1 mM CT at CD-AE-NG/GCE in 0.1 M pH 4.0 citrate-phosphate buffer by LSV; Stirring speed: 400 rpm. (E) DPV curves of CT with different concentrations at CD-AE-NG/GCE in 0.1 M pH 4.0 citrate-phosphate buffer; (F) The plots of Ip vs. concentrations for CT. Figure 4. DPVs obtained for the oxidation of 0.1 mM APAP and Tyr at bare GCE (a), GO/GCE (b), NG/GCE (c), AE-NG/GCE (d), CD-NG/GCE (e) and CD-AE-NG/GCE (f) in 0.1 M pH 7.4 PBS

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containing 20% human serum. Pulse width: 0.05s; amplitude: 0.05V. Figure 5. (A) DPV curves of various concentrations of APAP and Tyr in the range from 0.5 to 1000 μM at CD-AE-NG/GCE in 0.1 M pH 7.4 PBS containing 20% human serum; (B) The plots of Ip vs. concentrations for APAP and Tyr, respectively. Table 1 Determination of CT at various concentrations in Nanjing River Water.

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Scheme 1.

35



Figure 1.

(B) (a) GO

17281624

(b) CD 2924

(c) AE

1417 2209

1610 1592 1494 1510

(d) NG

3309 2920

1580 1489

(e) AE-NG

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(f) CD-NG

3500

3000

1416

(g) CD-AE-NG

2500

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2000

1500

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60 40 20

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100

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CD-AE-NG AE-NG

ID/IG=1.13 CD-NG NG

ID/IG=1.00

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GO

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AE AE-NG CD-NG CD-AE-NG

c

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0 500

500

df

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(D)

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Charge transfer resistance/RCT

1018

400

O

180 2171

300

Temperature ( C)

Wavenumber (cm )

1281

(C)

O

100

1048

Weight (wt%)

Transmittance (a.u.)

3337

2928

Intensity (a.u.)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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1000 1500 2000 2500 3000 3500 4000 -1

0

Raman Shift (cm )

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Figure 2.

d

Current (μ A)

Current (μ A)

f

e

30

c

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b

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0.2

0.4

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5

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0.4

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0.6

0.8

1.0

0 0.4

1.2


0.6

0.8


37


1.0


Figure 3.

Peak potential (V vs. SCE)

pH 3 pH 4 pH 5 pH 6 pH 7

49

Current (μ A)

(B)

(A)

56

42 35 28 21 14 7 0 -0.4

-0.2

0.0

0.2

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3

4

Potential (V vs. SCE) (C)

Current (μ A)

Current (μ A)

30

0

20

40

35

20 10 0.0

0.2

0.4

0.6

(E)

60

-0.1

0.0

0.1

IP,2 = 32.424 + 0.065 CCT

0.2

(F)

R2 = 0.9994

50

curve 2

IP (μA)

30

-0.2

Accumulation potential (V vs. SCE) 400 μ M 330 μ M 270 μ M 220 μ M 170 μ M 130 μ M 90 μ M 50 μ M 25 μ M 20 μ M 15 μ M 12 μ M 10 μ M 8 μM 6 μM 4.5 μ M 3.5 μ M 2.5 μ M 2 μM 1.5 μ M 1 μM 0.5 μ M 0.3 μ M 0.05 μ M

40

(D)

40

Accumulation time (s)

50

7

45

30

60

60

6

50

35

25

5

Detection medium pH

40

Current (μA)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 38 of 42

40 IP,1 = 21.453 + 0.491 CCT

30

0.8

R1 = 0.9998

curve 1

20 0

100

200

cCT (μM)


38


300

400

Page 39 of 42

Figure 4.

6

f

5

Current (μA)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


e 4

d

3

c

b

2

a

1 0.0

0.2

0.4

0.6


39


0.8

1.0


Figure 5.

A

APAP

14 1000 μM 700 μM 450 μM 200 μM 100 μM 60 μM 30 μM 10 μM 5 μM 0.5 μM

Current (μ A)

12 10 8 6 4 2 0 0.0

Tyr

0.2

0.4

0.6

0.8

1.0


B

15 IP,2 = 2.448 + 0.011 cAPAP R = 0.999

12 9

IP (μ A)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 40 of 42

IP,1 = 1.118 + 0.022 cAPAP

6 R = 0.999 3 IP,2 = 1.306 + 0.004 cTyr R = 0.994

0

IP,1 = 0.721 + 0.008 cTyr R = 0.999

0

200

400

600

800

c (μM)

40


1000

Page 41 of 42 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Table 1 DPV Samples

CT

a Average

UV–vis

Spiked (μM) Founda (μM)

Recovery (%)

Founda (μM)

Recovery (%)

0

-

-

-

-

10

10.14 ± 0.38

101.4

10.16 ± 0.15

101.6

70

69.84 ± 0.52

99.8

70.05 ± 0.30

100.1

of three measurements.

41




Page 42 of 42

Heterojunctions Derived by Integrating Arylene-Ethynylene Nanobelts

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