Simple and Large-Scale Strategy to Prepare ... - ACS Publications

Subscriber access provided by University of Newcastle, Australia

Article

A Simple and Large-Scale Strategy to Prepare Flexible Graphene Tape Electrode Li Wang, Jie Yu, Yayun Zhang, Han Yang, Longfei Miao, and Yonghai Song ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.6b14624 • Publication Date (Web): 21 Feb 2017 Downloaded from http://pubs.acs.org on February 22, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

ACS Applied Materials & Interfaces is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 27

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

ACS Applied Materials & Interfaces

A Simple and Large-Scale Strategy to Prepare Flexible Graphene Tape Electrode Li Wang*, Jie Yu, Yayun Zhang, Han Yang, Longfei Miao and Yonghai Song∗

Key Laboratory of Functional Small Organic Molecule, Ministry of Education, Key Laboratory of Chemical Biology, Jiangxi Province, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, China.

∗

Corresponding author: Tel: +86 791 88120861. E-mail: [email protected] (Y. Song) and

[email protected]. 1

ACS Paragon Plus Environment


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

ABSTRACT A simple and large-scale strategy to prepare flexible graphene tape electrode (GTE) was proposed. The flexible GTE was prepared by a facile peeling method in which a piece of commercial graphite foil was firstly covered by a commercial acrylic transparent tape and then the transparent adhesive tape was quickly torn off from the graphite foil. Scanning electron microscopy results showed that some folded and wrinkled graphene layers stood up on the GTE surface to form three-dimensional (3D) porous graphene foam. The 3D porous flexible GTE was proposed as a novel supporting matrix to load Ni-Co nanoparticles (Ni-CoNPs) and glucose oxidase (GOD) as examples to test its applications for electrochemical glucose sensing. The Ni-CoNPs/GTE showed the linear range of 0.6 µM-0.26 mM and 1.360-5.464 mM with a detection limit of 0.16 µM. The GOD/AuNPs-CHIT/GTE had a linear range of 0.616-14.0 mM and a detection limit of 0.202 mM. These results were similar or superior to the printable electrodes by nanocarbon and electrodes modified with graphene, carbon nanotubes or porous carbon materials, but the flexible GTE was more easier to prepare in large-scale and the 3D porous graphene foam were not easy to drop off from the tape because they were glued on acrylic transparent tape firmly. Therefore, the 3D porous flexible GTE should be promising candidates for electrochemical sensors and other electrochemical applications. Keywords: Flexible graphene tape electrode; Graphite foils; Acrylic transparent tape; Ni-Co nanoparticles; Glucose oxidase; Electrochemical glucose sensors

2


Page 2 of 27

Page 3 of 27

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


INTRODUCTION Electrochemical sensors have attracted extensive interests due to their small portable instruments, easy operation, fast signal conversion, etc.1,2 Lots of electrochemical sensors were constructed based on the solid supporting electrodes as supporting matrix, including gold electrode,3,4 Pt electrode,5,6 glassy carbon electrode (GCE),7,8 etc. The solid supporting electrodes increase the cost of electrochemical sensors and the inconvenience of their application. Furthermore, the solid supporting electrodes need be polished before each use to obtain a clean and smooth surface for loading active materials, which will not only result in a poor reproducibility of the as-prepared electrochemical sensors, but also complicate the preparation. Besides, to improve the sensitivity and the response time of electrochemical sensors, the solid supporting electrodes are generally modified by nanomterials to increase the specific surface area for loading more active materials. Among these nanomaterials, graphene has attracted extensive attention owing to its two-dimensional (2D) single carbon atom layer nanostructures, fast electron transfer ability, strong adsorption capacity, good mechanical properties and flexibility.9-11 A series of preparation procedures have been developed to obtain graphene, such as chemical vapor deposition (CVD),12-14 epitaxial growth,15-18 chemical/thermal reduction,19-21 liquid phase,22,23 electrochemical exfoliation,24-26 etc. These preparation procedures always are high cost, time-consuming as well as low productivity. The feasible method to modify the solid supporting electrodes by graphene is the cast-film. Here, the graphene suspension is cast on electrode surface directly. However, after the 2D graphene is cast on electrode surface, it is very easy to stack into massive structures and fall off. Accordingly, the electrochemical deposition and CVD method27,28 are developed to prepare the graphene modified electrodes, in which the graphene sheets can grow on electrode surface to form 3



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

three-dimensional (3D) graphene electrodes. For example, single- to few-layer graphene on polycrystalline Ni film electrodes was constructed by CVD method.27 However, these modification methods are very inconvenient, time-consuming and high valuable. Electrochemical exfoliation is another alternative method to prepare graphene modified electrode, in which some oxidizing agents such as nitric acid or sulfuric acid and reducing agents such as dimethylhydrazine are used. These agents can always cause various pollution problems. Moreover, the process is time-consuming and materials-consuming. What’s more, graphene gotten from this method might not exfoliate averagely. Therefore, developing simple, flexible and low-cost method to prepare graphene modified electrode for electrochemical application is very important. Herein, a simple and large-scale method to fabricate flexible graphene tape electrode (GTE) was proposed based on Geim and Novoselov’s method.29-32 Although the preparation of graphene using sticky tape peeling method is well known, it is the first time to use the well-known method to construct GTE electrode. Some folded and wrinkled graphene layers formed and stood up on the surface of GTE to set up 3D porous graphene foam in the peeling process. The 3D porous flexible GTE was proposed as a novel supporting matrix to replace the solid electrode for loading Ni-Co nanoparticles (Ni-CoNPs) and glucose oxidase (GOD) to test its application in electrochemical sensing and biosensing. The results showed a good performance, superior to previous sensors based on the solid supporting electrodes.

EXPERIMENTAL SECTION Chemicals and Reagents. Acrylic transparent tape was purchased from Deli Company. GOD (140 U mg−1) was purchased from Sigma–Aldrich. Commercial graphite foil, glucose, chitosan (CHIT), CoCl2·6H2O, NiCl2·6H2O, HAuCl4 and other reagents were purchased from Sinopharm Chemical Reagent Co. Ltd (Shanghai, China). 0.1 M phosphate buffer solution (PBS) was obtained by mixing 4


Page 4 of 27

Page 5 of 27

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


0.1 M NaH2PO4 and Na2HPO4. The GOD solution (10 mg mL−1) was prepared in 0.1 M PBS (pH 7.0) and stored at 4 °C for use. Millipore-Q ultra-pure water (18.2 MΩ cm-1) was used throughout all experiments. Preparation of the flexible GTE. The GTE was prepared by a facile peeling method as shown in Scheme 1. Firstly, the commercial graphite foils were ultrasonic in acetone, ethanol and ultra-pure water for 15 min, respectively. Then the as-pretreated graphite foils were dried in a hot oven at 60 °C for 12 h. Secondly, the clean and dried graphite foils were cut into appropriate size (1 cm x 2 cm). Thirdly, a piece of graphite foil was placed on a cleaning glass plate, and then the commercial acrylic transparent tape was covered on the piece of foil. After pressed by other glass plate or glass rod, the transparent adhesive tape was quickly torn off from the piece of graphite foil. Lastly, the parts of the transparent adhesive tape without graphite were trimmed off to get the 3D porous flexible GTE. “Here for Scheme 1” Preparation of the flexible Ni-CoNPs/GTE. To obtain the Ni-CoNPs modified flexible GTE, the flexible GTE fixed by electrode clamp was immersed in a aqueous solution containing 0.1 M KCl, 0.005 M NiCl2 and 0.005 M CoCl2 and then a cyclic voltammograms (CVs) scan at the voltage window between -0.05 V and -1.05 V was performed to electrodeposit Ni-CoNPs on the flexible GTE surface.33 The scan cycle number was optimized to be 20 to construct the flexible Ni-CoNPs/GTE for the following experiments. Preparation of the GOD/AuNPs-CHIT/GTE. The flexible GTE was firstly immersed in 10 mL aqueous solution containing 0.05 wt% CHIT and 300 mg L-1 HAuCl4 and then a constant potential of -2.5 V was applied for 240 s to electrodeposit AuNPs-CHIT on the flexible GTE surface.34 Then the AuNPs-CHIT/GTE was immersed into 100 µL 10 mg L-1 GOD solution at 4 °C for 24 h to form 5



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

the flexible GOD/AuNPs-CHIT/GTE. The GOD/GTE was also prepared by the same method expect the electrodepositing of AuNPs-CHIT. Instruments. Electrode clamp was bought from Tianjin British Branch Joint Technology Company (Tianjin, China). Scanning electron microscopy (SEM) images were obtained using a HITACHI S-3400N scanning electron microscope at an accelerating voltage of 15 kV. CVs, electrochemical impedance spectroscopy (EIS), chronoamperometry and linear sweep voltammetry (LSV) were performed on a CHI 760E electrochemical workstation (Shanghai, China). A conventional three-electrode system was adopted including a platinum wire as the counter electrode, a saturated calomel electrode (SCE) as the reference electrode and the flexible GTE, Ni-CoNPs/GTE and GOD/AuNPs-CHIT/GTE as the working electrode. The set-up of the flexible GTE was illustrated in Figure S1 (Supporting information).

RESULTS AND DISCUSSION Characterization of the Flexible GTE. The morphologies of flexible GTE were examined by SEM. SEM image (Figure 1A) revealed that the typical layered fold structure of graphene appeared on the flexible GTE and the surface of the flexible GTE became very rough accordingly. The high-magnification SEM image (Figure 1D) showed that the folded and wrinkled graphene layers stood up on the surface of GTE to form 3D porous graphene foam which was similar to and even better than that peeled from the graphite foils by chemical or electrochemical methods.35 Noticeably, the preparation strategy was very simple and facile as compared with chemical and electrochemical exfoliation methods. Furthermore, one piece of graphene foil could be used to prepare lots of GTE. As shown in Figure 1B, C, E and F, the morphologies of GTEs obtained from the same graphite foils were very similar to that in Figure 1A and D, indicating the flexible GTEs could be prepared in large-scale through the simple method. 6


Page 6 of 27

Page 7 of 27

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


“Here for Figure 1” The effective potential window36 might strongly affect the further electroanalytical application of the flexible GTE and accordingly LSV tests (Figure 2A) were performed to explore the effective potential window of the flexible GTE. As shown in Figure 2A, the potential window of the flexible GTE (curve b) was about 2.0 V, close to the GCE (curve a), indicating the flexible GTE could be applied as working electrode. The electron transfer ability of GTE was also studied by EIS (Figure 2B). Based on the Randles equivalence circuit model (Inset in bottom-right), the complex impedance spectrum could effectively reflect two aspects information: circular part (high frequency) corresponds to the electron transfer process and the linear part (low frequency) represents a diffusion limited process.37 As shown in Figure 2B, the lacking of circular part indicated that the flexible GTE showed the fast electron transfer due to the excellent electrical conductivity (Table S1, Supporting Information), similar to that of the GCE (Inset in top-left). Both GTE and GCE have the same slope being close to 45° that is characteristic for a diffusion process, indicating the rapid mass transfer owing to the 3D porous structure of GTE. The CVs of GTEs prepared from the same piece of graphite foils were carried out by using 5 mM [Fe(CN)6]3−/4− as electroactive probe. As shown in Figure 2C, although the peak-to-peak potential (∆Εp) seemed to be larger than of bare GCE, no obvious difference of peak current and ∆Εp were observed between these GTEs, indicating the electrochemical behaviors of GTEs prepared from the same piece of graphite foils were similar. Inset in Figure 2D clearly revealed the good flexibility of the GTE. After it was bent, the same CVs were observed (Figure 2D), indicating the bending had no effect on the structure (Figure S2, Supporting Information) and electrochemical performance of GTE. The results showed a potential for some special sensing for the GTE, just like printable electrode by nanocarbon ink.38 The preparation of printable electrode by nanocarbon ink also was 7



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

very convenient and simple. Although it could be prepared in various shapes, the modified nanocarbon was easy to drop off just like most modified electrodes. Furthermore, the nanocarbon was also easy to aggregate on the surface of electrode. As compared with the printable electrode by nanocarbon ink, the graphene nanaosheets were not easy to drop off from the tape because they were glued on acrylic transparent tape firmly. The 3D porous graphene foam also was superior to the printable electrode. Since the preparation of GTE was very simple and the graphene foils could be obtained commercially, the reproducibility of GTE should be more convenient. About all, the electrochemical results clearly indicated that the flexible GTE was suitable as supporting matrix for electrochemical application. “Here for Figure 2” Electrochemical and Electrocatalytic Behaviors of Ni-CoNPs/GTE towards Glucose. As a popular and deadly disease, diabetes mellitus is related to the blood glucose level directly.39-42 Herein, the Ni-CoNPs possessing the nature of artificial enzyme was loaded on the flexible GTE to construct an electrochemical nonenzymatic glucose sensor for fast and easy monitoring of blood glucose level as an example to test the potential of the flexible GTE as supporting matrix for electrochemical sensing. The Ni-CoNPs/GTE showed the same flexibility as the GTE (Figure S3A, Supporting Information). CVs were used to electrodeposit Ni-CoNPs on the flexible GTE to construct Ni-CoNPs/GTE. A cathodic peak at -1.05 V which might be ascribed to the reduction of Ni2+ and Co2+ indicated the formation of Ni-CoNPs (Figure S4A, Supporting Information). Figure S4B (Supporting Information) showed that flower-like Ni-CoNPs were formed on the GTE surface. EDX (Figure S5A, Supporting Information) and XRD (Figure S5B, Supporting Information) further confirmed the formation of Ni-CoNPs/GTE and the ratio of Ni/Co was about 1:1.33,43 The electrochemical behaviors of 8


Page 8 of 27

Page 9 of 27

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


Ni-CoNPs/GTE were also explored in Figure S4C and D (Supporting Information), which was agreeable with our previous work.33 Next, the performance of nonenzymatic electrochemical glucose sensor based on the flexible Ni-CoNPs/GTE was explored. Figure 3A showed that the oxidation peak was obviously increased and the corresponding reduction peak was decreased after the addition of glucose (curve b and c), indicating glucose was oxidized by Ni-CoNPs catalyst.33,44 The amperometric responses were used to explore the oxidation of glucose on the Ni-CoNPs/GTE at 0.5 V (Figure S6, Supporting Information) as shown in Figure 3B. The linear range of the glucose detection was from 0.6 µM to 260 µM (R2 = 0.992) and from 1.360 mM to 5.464 mM (R2=0.983) accompanied by a detection limit of 0.16 µM (Figure 3C). Two linear ranges were also found in some previous works.45,46 It might be ascribed to the active Ni-CoNPs which could adsorb the analytes. In low concentration of glucose, only a few analytes could adsorb on Ni-CoNPs and abundant exposed active sites resulted in a high sensitivity. While, in the high concentration of glucose, lots of analytes adsorbed on the surface of Ni-CoNPs to decrease the active sites, which led to a poor sensitivity. The obtained results were similar or superior to previous results (Table S2, Supporting Information). Figure 3D indicated that some possible chemicals (20-folded K+, NO2-, SO42- and 5-folded fructose, D-galactose, mannose and uric acid) only showed slight inference to glucose detection. The sensor also had good stability (Figure S7, Supporting Information) and could monitor glucose in blood serum (Table S3, Supporting Information). The above results indicated that the flexible GTE could be used as supporting matrix for electrochemical sensing. “Here for Figure 3” Electrochemical and Electrocatalytic Behaviors of the GOD/AuNPs-CHIT/GTE towards glucose. The glucose could be indirectly detected by testing the amount of oxygen consumption 9



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

with the help of GOD.45,46 Therefore, the flexible GTE was further used to load GOD to test its application for biosensors. The AuNPs-CHIT was firstly deposited on the flexible GTE to enhance the immobilization of GOD and the increased peak current and decreased ∆Εp confirmed the formation of AuNPs-CHIT (curve a and b in Figure 4A). The electrodeposited AuNPs-CHIT could not only improve the immobilization of GOD, but also keep their bioactivity (Figure S8, Supporting Information) and enhance the catalytic activity toward the reduction of O2 (Figure S9, Supporting Information). After GOD were immobilized on the AuNPs-CHIT/GTE, the peak current decreased and the ∆Εp became larger owing to the blocking of GOD molecules toward [Fe(CN)6]3−/4− (curve c), indicating the successful immobilization of GOD. The GOD/AuNPs-CHIT/GTE also showed the same flexibility as the GTE (Figure S3B, Supporting Information). The GOD/AuNPs-CHIT/GTE showed the typical redox peaks of FAD/FADH2 (the electroactive center of GOD) (Figure 4B).48-51 The linear change of peak current with scan rate from 10 to 150 mV s−1 (Figure 4C) suggested the electron transfer reaction resulted from a surface-controlled process. The electron-transfer rate constant (ks) was estimated according to Laviron theory52 to be 3.89 s−1, higher than previous results.47, 53,54 The E0 ((Epa + Epc)/2) exhibited a linear dependence on pH with a slope of -62 mV/pH, close to the theoretical value (-58.6 mV/pH) of FAD/FADH2 (Figure S10, Supporting Information).49,50 The results indicated that the flexible GTE could promote the direct electron transfer of GOD. Next, the GOD/AuNPs-CHIT/GTE was used to detect glucose (Figure 4D). As shown in Figure 4D, the cathodic current decreased linearly with the increasing glucose concentration in the range of 0.616-14.0 mM (R=0.992) with a detection limit of 0.202 mM and a sensitivity of 9 µA mM−1 cm−2 (Inset in Figure 4D). The results were superior to that of GOD/GTE (Figure S8, Supporting Information). As compared with the excellent printed nanotubes-based electrochemical glucose 10


Page 10 of 27

Page 11 of 27

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


sensor,38 the GOD/AuNPs-CHIT/GTE also showed a wider linear range, which might result from the 3D porous graphene foam nanostructures of the flexible GTE. Detailed comparison between the GOD/ AuNPs-CHIT/GTE electrode and other GOD-based glucose biosensors (Table S4, Supporting Information) indicated that the flexible GOD/Au-CHIT/GTE biosensor offered reasonable performances. Such performances indicated that the as-prepared flexible GTE could also be used for electrochemical biosensing. “Here for Figure 4” The selectivity of GOD/AuNPs-CHIT/GTE biosensor was also studied. Figure S11A (Supporting Information) presented the catalytic current response of the GOD/AuNPs-CHIT/GTE biosensor to glucose and 10-fold concentration of interfering substances. No obvious interference was observed, indicating good selectivity. The stability of GOD/AuNPs-CHIT/GTE biosensor was also investigated (Figure S11B, Supporting Information). After 15 days, the catalytic current response of 1.0 mM glucose decreased by 6.4 %, demonstrating a good stability. The detection of glucose in blood serum sample showed the biosensor performing very well (Table S5, Supporting Information). The good selectivity, stability and practicability of GOD/AuNPs-CHIT/GTE make it a promising candidate for glucose detection. Comparing the two kinds of glucose sensors based on the GTE, the GOD/AuNPs-CHIT/GTE showed a wide linear range, while the preparation process of Ni-CoNPs/GTE was more convenient and needn’t store in refrigerator. Besides, their linear ranges were wide enough for the typical normal value of serum glucose. So, the above two kinds of GTE-based glucose sensors both showed good performance in glucose detection. The results confirmed that the flexible GTE could be a promising candidate instead of the solid supporting electrode.

11



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

CONCLUSIONS In conclusion, a facile peeling step to prepare flexible 3D porous GTE in large-scale was proposed for the first time. The folded and wrinkled graphene layers stood up on the surface of GTE to form 3D porous graphene foam which was glued on acrylic transparent tape firmly. The flexible GTE showed a large potential window (2.0 V) and good electron transfer ability. The Ni-CoNPs and GOD were employed to modify GTE as the examples to test its application in electrochemical sensing and biosesing. The flexible Ni-CoNSs/GTE showed low detection limit, good stability and wide linear range. The GOD/AuNPs-CHIT/GTE also showed good performances towards glucose detection, which was similar or superior to previous sensors modified by graphene, carbon nanotubes or porous carbon materials. Therefore, these results confirmed that the proposed 3D porous flexible GTE should be a promising candidate instead of the solid supporting electrode for electrochemical applications.

ASSOCIATED CONTENT The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.analchem.xxxxx. The installation process of GTE working electrode; SEM of GTE after it was bent for 200 times with different magnification; the digital pictures of bending Ni-CoNPs/GTE and GOD/AuNPs-CHIT/GTE; CVs of GTE in 0.1 M KCl + 0.005 M NiCl2 + 0.005 M CoCl2; SEM images of Ni-CoNPs/GTE; CVs of Ni-CoNPs/GTE in 0.1 M NaOH at different scan rates; plot of peak potential versus the root of scan rates; EDX and XRD of Ni-CoNPs/GTE; electrocatalytic oxidation of glucose on Ni-CoNPs/GTE at different applied potentials; stability test of the Ni-CoNPs/GTE; CVs of GOD/GTE at different scan rates by step of 10 mV s-1 in 0.1 M N2-saturated PBS; CVs of GOD/GTE in 0.1 M O2-saturated PBS (pH=7.0) 12


Page 12 of 27

Page 13 of 27

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


in the presence of glucose with various concentrations; CVs responses of GTE and AuNPs-CHIT/GTE under different oxygen partial pressures; CVs of GOD /AuNPs-CHIT/ GTE in 0.1 M N2-saturated PBS at different pH; plots of peak potential versus lnυ; selectivity test and stability test of GOD/Au-CHIT/GTE biosensor; electrical conductivity of GTE and GCE; comparison of the performance of various Ni-based glucose sensors; determination of glucose in blood serum sample of Ni-CoNPs/GTE; comparison of the performance of various GOD-based glucose sensors; determination of glucose in blood serum sample of GOD /AuNPs-CHIT/GTE (PDF) AUTHOR INFORMATION Corresponding Author *Tel/Fax: +86-791-88120861. E- mail: [email protected] (Y. Song). * E- mail: [email protected] (L. Wang). ORCID Yonghai Song: 0000-0002-7889-2439 Notes The authors declare no competing financial interest. ACKNOWLEDGMENT This work was financially supported by National Natural Science Foundation of China (21165010, 21465014 and 21465015), Natural Science Foundation of Jiangxi Province (20143ACB21016), The Ministry of Education by the Specialized Research Fund for the Doctoral Program of Higher Education (20133604110002) and the Ground Plan of Science and Technology Projects of Jiangxi Educational Committee (KJLD14023).

13



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

REFERENCE 1. Privett, B. J.; Shin, J. H.; Schoenfisch, M. H. Electrochemical Sensors. Anal. Chem. 2008, 80 (12), 4499-4517. 2. Kimmel, D. W.; Leblanc, G.; Meschievitz, M. E.; Cliffel, D. E. Electrochemical Sensors and Biosensors. Anal. Chem. 2012, 84 (2), 685-707. 3. Vogt, S.; Su, Q.; Gutierrez-Sanchez, C.; Noll, G. Critical View on Electrochemical Impedance Spectroscopy Using the Ferri/Ferrocyanide Redox Couple at Gold Electrodes. Anal. Chem. 2016, 88 (8), 4383-4390. 4. Lazar, J.; Schnelting, C.; Slavcheva, E.; Schnakenberg, U. Hampering of the Stability of Gold Electrodes by Ferri-/Ferrocyanide Redox Couple Electrolytes during Electrochemical Impedance Spectroscopy. Anal. Chem. 2016, 88 (1), 682-687. 5. Li, Y. X.; Wu, Q. Q.; Jiao, S. F.; Xu, C. D.; Wang, L. Single Pt Nanowire Electrode: Preparation, Electrochemistry, and Electrocatalysis. Anal. Chem. 2013, 85 (8), 4135-4140. 6. Matsumoto, N.; Chen, X. H.; Wilson, G. S. Fundamental Studies of Glucose Oxidase Deposition on a Pt Electrode. Anal. Chem. 2002, 74 (2), 362-367. 7. Gupta, R.; Gamare, J. S.; Pandey, A. K.; Tyagi, D.; Kamat, J. V. Highly Sensitive Detection of Arsenite Based on Its Affinity toward Ruthenium Nanoparticles Decorated on Glassy Carbon Electrode. Anal. Chem. 2016, 88 (4), 2459-2465. 8. Li, X. C.; Zheng, W.; Zhang, L. M.; Yu, P.; Lin, Y. Q.; Su, L.; Mao, L. Q. Effective Electrochemical Method for Investigation of Hemoglobin Unfolding Based on the Redox Property of Heme Groups at Glassy Carbon Electrodes. Anal. Chem. 2009, 81 (20), 8557-8563. 9. Pu, L.; Baig, M.; Maheshwari, V. Nanoparticle Chains as Electrochemical Sensors and Electrodes. Anal. Bioanal. Chem. 2016, 408 (11), 2697-2705. 14


Page 14 of 27

Page 15 of 27

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


10. Karuppiah, C.; Velmurugan, M.; Chen, S. M.; Devasenathipathy, R.; Karthik, R.; Wang, S. F. Electrochemical Activation of Graphite Nanosheets Decorated with Palladium Nanoparticles for High Performance Amperometric Hydrazine Sensor. Electroanalysis 2016, 28 (4), 808-816. 11. Xue, Q.; Liu, Z.; Guo, Y.; Guo, S. Cyclodextrin Functionalized Graphene-Gold Nanoparticle Hybrids with Strong Supramolecular Capability for Electrochemical Thrombin Aptasensor. Biosens. Bioelectron. 2015, 68, 429-436. 12. Purwidyantri, A.; Chen, C. H.; Hwang, B. J.; Luo, J. D.; Chiou, C. C.; Tian, Y. C.; Lin, C. Y.; Cheng, C. H.; Lai, C. S. Spin-Coated Au-Nanohole Arrays Engineered by Nanosphere Lithography for a Staphylococcus Aureus 16S rRNA Electrochemical Sensor. Biosens. Bioelectron. 2016, 77, 1086-1094. 13. Liu, Y. L.; Jin, Z. H.; Liu, Y. H.; Hu, X. B.; Qin, Y.; Xu, J. Q.; Fan, C. F.; Huang, W. H. Stretchable Electrochemical Sensor for Real-Time Monitoring of Cells and Tissues. Angew. Chem. Int. Ed. 2016, 55 (14), 4537-4541. 14. Jiang, G. P.; Goledzinowski, M.; Comeau, F. J. E.; Zarrin, H.; Lui, G.; Lenos, J.; Veileux, A.; Liu, G. H.; Zhang, J.; Hemmati, S.; Qiao, J. L.; Chen, Z. W. Free-Standing Functionalized Graphene Oxide Solid Electrolytes in Electrochemical Gas Sensors. Adv. Funct. Mater. 2016, 26 (11), 1729-1736. 15. Nguyen, T. T.; Nguyen, V. H.; Deivasigamani, R. K.; Kharismadewi, D.; Iwai, Y.; Shim, J. J. Facile Synthesis of Cobalt Oxide/Reduced Graphene Oxide Composites for Electrochemical Capacitor and Sensor Applications. Solid. State. Sci. 2016, 53, 71-77. 16. Wang, Y.; Zhang, S.; Bai, W.; Zheng, J. Layer-by-Layer Assembly of Copper Nanoparticles and Manganese Dioxide-Multiwalled Carbon Nanotubes Film: A New Nonenzymatic Electrochemical Sensor for Glucose. Talanta 2016, 149, 211-216. 15



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

17. Zaidi, S. A.; Shin, J. H. Recent Developments in Nanostructure Based Electrochemical Glucose Sensors. Talanta 2016, 149, 30-42. 18. Sun, J. Y.; Liu, Y.; Lv, S. M.; Huang, Z. R.; Cui, L.; Wu, T. An Electrochemical Sensor Based on Nitrogen-doped Carbon Nanofiber for Bisphenol A Determination. Electroanalysis 2016, 28 (3), 439-444. 19. Bakker, E.; Qin, Y. Electrochemical Sensors. Anal. Chem. 2006, 78 (12), 3965-3983. 20. Reisberg, S.; Piro, B.; Noel, V.; Pham, M. C. DNA Electrochemical Sensor Based on Conducting Polymer: Dependence of the "Signal-on" Detection on the Probe Sequence Localization. Anal. Chem. 2005, 77 (10), 3351-3356. 21. Zhao, M.; Hibbert, D. B.; Gooding, J. J. Solution to the Problem of Interferences in Electrochemical Sensors Using the Fill-and-Flow Channel Biosensor. Anal. Chem. 2003, 75 (3), 593-600. 22. Dobbelin, M.; Ciesielski, A.; Haar, S.; Osella, S.; Bruna, M.; Minoia, A.; Grisanti, L.; Mosciatti, T.; Richard, F.; Prasetyanto, E. A.; De Cola, L.; Palermo, V.; Mazzaro, R.; Morandi, V.; Lazzaroni, R.; Ferrari, A. C.; Beljonne, D.; Samori, P. Light-Enhanced Liquid-Phase Exfoliation and Current Photoswitching in Graphene-Azobenzene Composites. Nat. Commun. 2016, 7, 11090. 23. Haar, S.; El Gemayel, M.; Shin, Y.; Melinte, G.; Squillaci, M. A.; Ersen, O.; Casiraghi, C.; Ciesielski, A.; Samori, P. Enhancing the Liquid-Phase Exfoliation of Graphene in Organic Solvents upon Addition of N-Octylbenzene. Sci. Rep. 2015, 5, 16684. 24. Yang, S.; Bruller, S.; Wu, Z. S.; Liu, Z.; Parvez, K.; Dong, R.; Richard, F.; Samori, P.; Feng, X.; Mullen, K. Organic Radical-Assisted Electrochemical Exfoliation for the Scalable Production of High-Quality Graphene. J. Mater. Chem. 2015, 137 (43), 13927-13932. 25. Lu, W.; Liu, S.; Qin, X.; Wang, L.; Tian, J.; Luo, Y.; Asiri, A. M.; Al-Youbi, A. O.; Sun, X. P. 16


Page 16 of 27

Page 17 of 27

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


High-yield, Large-Scale Production of Few-Layer Graphene Flakes within Seconds: Using Chlorosulfonic Acid and H2 O2 as Exfoliating Agents. J. Mater. Chem. 2012, 22 (18), 8775-8777. 26. Shinde, D. B.; Brenker, J.; Easton, C. D.; Tabor, R. F.; Neild, A.; Majumder, M. Shear Assisted Electrochemical Exfoliation of Graphite to Graphene. Langmuir 2016, 32 (14), 3552-3559. 27. Reina, A.; Jia, X.; Ho, J.; Nezich, D.; Son, H.; Bulovic, V.; Dresselhaus, M. S.; Kong, J. Large area, Few-Layer Graphene Films on Arbitrary Substrates by Chemical Vapor Deposition. Nano Lett. 2009, 9 (1), 30-35. 28. Sheng, Z. H.; Shao, L.; Chen, J. J.; Bao, W. J.; Wang, F. B.; Xia, X. H. Catalyst-Free Synthesis of Nitrogen-Doped Graphene via Thermal Annealing Graphite Oxide with Melamine and Its Excellent Electrocatalysis. ACS Nano 2011, 5 (6), 4350-4358. 29. Geim, A. K. Graphene: Status and Prospects. Science 2009, 324 (5934), 1530-1534. 30. Geim, A. K.; Novoselov, K. S. The Rise of Graphene. Nat. Mater. 2007, 6 (3), 183-191. 31. Novoselov, K. S.; Geim, A. K.; Morozov, S. V.; Jiang, D.; Zhang, Y.; Dubonos, S. V.; Grigorieva, I. V.; Firsov, A. A. Electric Field Effect in Atomically Thin Carbon Films. Science 2004, 306 (5696), 666-669. 32. Park, S.; Ruoff, R. S. Chemical Methods for the Production of Graphenes. Nat. Nanotechnol. 2009, 4 (4), 217-224. 33. Wang, L.; Lu, X. P.; Ye, Y. J.; Sun, L. L.; Song, Y. H. Nickel-Cobalt Nanostructures Coated Reduced Graphene Oxide Nanocomposite Electrode for Nonenzymatic Glucose Biosensing. Electrochim. Acta 2013, 114, 484-493. 34. Song, Y. H.; Liu, H. Y.; Wang, Y.; Wang, L. A Glucose Biosensor Based on Cytochrome c and Glucose Oxidase Co-Entrapped in Chitosan-Gold Nanoparticles Modified Electrode. Anal. Methods 2013, 5 (16), 4165-4171. 17



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

35. Song, Y.; Xu, J. L.; Liu, X. X. Electrochemical Anchoring of Dual Doping Polypyrrole on Graphene Sheets Partially Exfoliated from Graphite Foil for High-Performance Supercapacitor Electrode. J. Power Sources 2014, 249, 48-58. 36. Zhang, J.; Liu, X. H.; Neri, G.; Pinna, N. Nanostructured Materials for Room-Temperature Gas Sensors. Adv. Mater. 2016, 28 (5), 795-831. 37. Hu, C. Y.; Yang, D. P.; Wang, Z. Y.; Yu, L. L.; Zhang, J. H.; Jia, N. Q. Improved EIS Performance of an Electrochemical Cytosensor Using Three-Dimensional Architecture Au@BSA as Sensing Layer. Anal. Chem. 2013, 85 (10), 5200-5206. 38. Bandodkar, A. J.; Jeerapan, I.; You, J. M.; Nunez-Flores, R.; Wang, J. Highly Stretchable Fully-Printed CNT-Based Electrochemical Sensors and Biofuel Cells: Combining Intrinsic and Design-Induced Stretchability. Nano Lett. 2016, 16 (1), 721-727. 39. Wei, C. T.; Li, X.; Xu, F. G.; Tan, H. L.; Li, Z.; Sun, L. L.; Song, Y. H. Metal Organic Framework-Derived Anthill-Like Cu@Carbon Nanocomposites for Nonenzymatic Glucose Sensor. Anal. Methods 2014, 6 (5), 1550-1557. 40. Tian, J.; Liu, Q.; Asiri, A. M.; Qusti, A. H.; Al-Youbi, A. O.; Sun, X. P. Ultrathin Graphitic Carbon Nitride Nanosheets: a Novel Peroxidase Mimetic, Fe, Doping-Mediated Catalytic Performance Enhancement and Application to Rapid, Highly Sensitive Optical Detection of Glucose. Nanoscale 2013, 5 (23), 11604-11609. 41. American Diabetes, A. Diagnosis and Classification of Diabetes Mellitus. Diabetes Care 2014, 37 Suppl 1, S81-90. 42. Ma, W.; Jiang, Q.; Yu, P.; Yang, L.; Mao, L. Zeolitic Imidazolate Framework-based Electrochemical Biosensor for in Vivo Electrochemical Measurements. Anal. Chem. 2013, 85 (15), 7550-7557. 18


Page 18 of 27

Page 19 of 27

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


43. Rashid, M. H.; Raula, M.; Mandal, T. K., Polymer Assisted Synthesis of Chain-Like Cobalt-Nickel Alloy Nanostructures: Magnetically Recoverable and Reusable Catalysts with High Activities. J. Mater. Chem. 2011, 21 (13), 4904-4917. 44. Mahshid, S. S.; Mahshid, S.; Dolati, A.; Ghorbani, M.; Yang, L. X.; Luo, S. L.; Cai, Q. Y. Electrodeposition and Electrocatalytic Properties of Pt/Ni-Co Nanowires for Non-enzymatic Glucose Detection. J. Alloy Compd. 2013, 554, 169-176. 45. Mu, Y.; Jia, D. L.; He, Y. Y.; Miao, Y. Q.; Wu, H. L. Nano Nickel Oxide Modified Non-enzymatic Glucose Sensors with Enhanced Sensitivity Through an Electrochemical Process Strategy at High Potential. Biosens. Bioelectron. 2011, 26 (6), 2948-2952. 46. Qiao, N. Q.; Zheng, J. B. Nonenzymatic Glucose Sensor Based on Glassy Carbon Electrode Modified with Nanocomposite Composed of Nickel Hydroxide and Graphene. Microchim. Acta 2012, 177 (1-2), 103-109. 47. Song, Y.; Lu, X.; Li, Y.; Guo, Q.; Chen, S.; Mao, L.; Hou, H.; Wang, L. Nitrogen-Doped Carbon Nanotubes Supported by Macroporous Carbon as an Efficient Enzymatic Biosensing Platform for Glucose. Anal. Chem. 2015, 88 (2), 1371-1377. 48. Unnikrishnan, B.; Palanisamy, S.; Chen, S. M. A Simple Electrochemical Approach to Fabricate a Glucose Biosensor Based on Graphene-Glucose Oxidase Biocomposite. Biosens. Bioelectron. 2013, 39 (1), 70-75. 49. Kang, X.; Wang, J.; Wu, H.; Aksay, I. A.; Liu, J.; Lin, Y. Glucose Oxidase-Graphene-Chitosan Modified Electrode for Direct Electrochemistry and Glucose Sensing. Biosens. Bioelectron. 2009, 25 (4), 901-905. 50. Liu, S.; Ju, H. Reagentless Glucose Biosensor Based on Direct Electron Transfer of Glucose Oxidase Immobilized on Colloidal Gold Modified Carbon Paste Electrode. Biosens. Bioelectron. 19



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

2003, 19 (3), 177-183. 51. Mani, V.; Devadas, B.; Chen, S. M. Direct Electrochemistry of Glucose Oxidase at Electrochemically Reduced Graphene Oxide-Multiwalled Carbon Nanotubes Hybrid Material Modified Electrode for Glucose Biosensor. Biosens. Bioelectron. 2013, 41, 309-315. 52. Laviron, E. General Expression of the Linear Potential Sweep Voltammogram in the Case of Diffusionless Electrochemical Systems. J. Electroanal. Chem. Interfacial Electrochem. 1979, 101 (1), 19-28. 53. Yin, H.; Zhao, S.; Wan, J.; Tang, H.; Chang, L.; He, L.; Zhao, H.; Gao, Y.; Tang, Z. Three-Dimensional Graphene/Metal Oxide Nanoparticle Hybrids for High-Performance Capacitive Deionization of Saline Water. Adv. Mater. 2013, 25 (43), 6270-6276. 54. Madhu, R.; Devadas, B.; Chen, S. M.; Rajkumar, M. An Enhanced Direct Electrochemistry of Glucose Oxidase at Poly(Taurine) Modified Glassy Carbon Electrode for Glucose Biosensor. Anal. Methods 2014, 6 (22), 9053-9058.

20


Page 20 of 27

Page 21 of 27

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


FIGURE CAPTIONS Scheme 1. Schematic illustration of the preparation process of the GTE. Figure 1. Low-magnification (A,B,C) and high-magnification (D,E,F) SEM images of first (A,D), third (B,E) and fifth (C,F) layer of the GTE. Figure 2. (A) LSVs of the GCE (curve a) and the GTE (curve b) in 0.1 M PBS pH=7.0 at 50 mV s-1. (B) EIS of the GTE and the GCE (Inset in top-right) in 0.1 M KCl containing 5 mM [Fe(CN)6]3−/4−. Inset in bottom-right is the Randles circuit model. (C) CVs of differently layered GTE in 0.1 M KCl solution containing 5 mM [Fe(CN)6]3−/4−. (D) CVs of the GTE with different bending times in 0.1 M KCl solution containing 5 mM [Fe(CN)6]3−/4−. Figure 3. (A) CVs of the GTE in 0.1 M NaOH in the absence (curve a) and presence of (curve b) 1.0 mM and (curve c) 2.0 mM glucose at 50 mV s−1. (B) Typical amperometric response of Ni-CoNPs/GTE to the successive injection of glucose into the stirred 0.1 M NaOH. (C) The plot of steady-state current versus the concentration of glucose. (D) The effects of some possible interfering substances on glucose detection. Applied potential: 0.5 V. Figure 4. (A) CVs of various electrodes in 0.1 M KCl solution containing 5 mM [Fe(CN)6]3−/4− at scan rate of 50 mV s-1: GTE (curve a), AuNPs-CHIT/GTE (curve b) and GOD/AuNPs-CHIT/GTE (curve c). (B) CVs of GOD/AuNPs-CHIT/GTE in 0.1 M PBS at different scan rates by step of 10 mV s-1. (C) Plot of peak current versus scan rates. (D) CVs of the GOD/AuNPs-CHIT/GTE in 0.1 M O2-saturated PBS (pH 7.0) at scan rate of 50 mV s

−1

with glucose concentration of 0, 1, and up

to 16 mM. Inset shows the calibration curve of GOD/AuNPs-CHIT/GTE.

21



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

Scheme 1

22


Page 22 of 27

Page 23 of 27

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


Figure 1

23



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

Figure 2

24


Page 24 of 27

Page 25 of 27

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


Figure 3

25



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

Figure 4

26


Page 26 of 27

Page 27 of 27

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


TOC

27


Simple and Large-Scale Strategy to Prepare ... - ACS Publications

Recommend Documents