Nanosized Difunctional Photo Responsive Magnetic Imprinting

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Nanosized Di-functional Photo Responsive Magnetic Imprinting Polymer for Electrochemically Monitored Light-Driven Paracetamol Extraction Yubo Wei, Qiang Zeng, Silan Bai, Min Wang, and Lishi Wang ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.7b14772 • Publication Date (Web): 29 Nov 2017 Downloaded from http://pubs.acs.org on December 5, 2017

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ACS Applied Materials & Interfaces

Nanosized Di-functional Photo Responsive Magnetic Imprinting Polymer for Electrochemically Monitored Light-Driven Paracetamol Extraction Yubo Weia, Qiang Zenga,b,*, Silan Baia, Min Wanga, Lishi Wanga* a

School of Chemistry and Chemical Engineering, South China University of

Technology, Guangzhou 510641, People's Republic of China b

State Key Laboratory of Pulp and Paper Engineering, South China University of

Technology, Guangzhou 510641, People's Republic of China *Corresponding author Email: [email protected] [email protected]

Abstract Herein, a novel photo responsive magnetic electrochemical imprinting sensor for the selective extraction of paracetamol from biological samples was designed. In particular, nanosized photo responsive molecular imprinted polymers were prepared on the surface of magnetic Fe3O4 nanoparticles through living radical polymerization of azobenzene. The introduction of a magnetic-controlled glassy carbon electrode makes the immobilization and removal of nanosized photo responsive molecular imprinted polymers on the magnetic-controlled glassy carbon electrode surface facilely operational. With the photo-responsive property, the sensor undergoes reversible release and uptake of paracetamol upon alternative irradiation at 365 nm and 440 nm basing on a configurational change of azobenzene monomer in the photo responsive molecular imprinted polymers receptor sites. Simultaneously, these processes are monitored by the photo responsive changes of electrochemical signal from paracetamol. Two linear ranges from 0.001 to 0.7 mmol L-1 (R2 = 0.96) and 0.7 to 7 mmol L-1 (R2 = 0.95) for paracetamol determination were obtained with a quantification limit of 0.00086 mmol L-1 and a detection limit of 0.00043 mmol L-1. 1

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The recoveries of paracetamol in the urine as determined by photo responsive molecular imprinted polymers extraction were varied between 87.5% - 93.3%. As a consequence, combining photo-controlled selective extraction, interfacial stability from magnetic adsorption and specifically electrochemical response, the photo responsive molecular imprinted polymers sensor shows significant advantages for simultaneous separation, enrichment, and detection of trace paracetamol in biological samples. Keywords: Magnetic nanoparticles; Molecular imprinting polymers; Photo-responsive materials; Solid-phase extraction; Paracetamol sensing

1. Introduction Paracetamol (acetaminophen, N-acetyl-p-aminophenol, PCM; MW: 151) is a typically used antipyretic and analgesic medicine for the effective relief of pain, fever, coughing and colds.1,2 But the accumulation of toxic metabolite from over recommended dosage of PCM will still lead to the damage to kidney and liver. Techniques including liquid chromatography,3 flow-injection,4 spectrophotometry,5 chemiluminescence,6 as well as electrochemistry due to the active redox property of PCM to N-acetyl-p-quinoneimine have been reported for therapeutic purposes in quality control and determination of PCM in pharmaceuticals and biological samples.7-10 While a fact of trace analysis of PCM by these methods has to be taken account, a step of sample enrichment and accumulation is necessary to be performed to eliminate the negative effects from complicated bio-environment and interferents. Molecularly imprinted polymers (MIPs), which have selective recognition sites for target molecules, have been applied to various applications in chemical sensors,11-14 catalysis,15 drug delivery,16 and solid phase extraction.17,18 In particular, acting as molecularly imprinted solid-phase extraction (MISPE) sorbents for sample enrichment, MIPs advance excellent selectivity to a specific target analyte and improve the accuracy in quantitation. However, the main drawback of most available MISPE sorbents in practical applications is their reusability. The template release after 2


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sample extraction usually is not efficient and requires a large volume of polar and acidic washing chemicals to break the interactions between MIPs and template molecules. Therefore, it is desirable to develop stimuli responsive MISPE sorbents that are able to realize extraction of templates from complicated actual samples and subsequently

release

them

only

upon

an

external

stimulus

such

as

photoirradiation,19,20 magnetic field,21 pH and temperature.22-24 The precise, superior cleaning, and remote controllable properties of light makes it an attractive external stimuli among these external stimuli powers. With the incorporation of light-sensitive monomers in a polymeric network, photo-responsive MIPs (P-MIPs) can be created and they carry out a photo-driven isomerization by converting the stimulus of photo-irradiation to a chemical signal.25-29 After carefully considering the advantages of P-MIPs and the unique electrochemical property of PCM, a novel magnetic electrochemical sensor basing on photo responsive MIPs was developed for photo-controlled PCM extraction and sensing from biological samples. P-MIPs were prepared from a light switchable monomer, azobenzene (AZO), which shows promising photo-driven reversible isomerization between their trans and cis forms when exposed to UV light.30-33 In order to increase active template imprinting sites and stability of P-MIPs on an electrode surface,34-36 the P-MIPs were fabricated on the surface of magnetic Fe3O4 nanoparticles through living radical polymerization.37-39 Finally, the nanosized P-MIPs were immobilized on a reduced graphene oxide (r-GO) modified magnetic-controlled glassy carbon electrode (MCGCE) (r-GO/MCGCE) through a flexibly installed magnet within the MCGCE. Therefore, the sensor is vested with sample self-extraction and -release functions by the P-MIPs, which are achieved from the photo-responsive configurational changes (cis → trans/trans → cis) upon programmed 440/365 nm light exposure. Meanwhile, the PCM extraction process can be quantitatively monitored and electrochemically reflected to the active PCM imprinted to P-MIPs on the electrode surface, resulting in sensing functionality. Comparing to the previous report of our group about thermo-responsive electrochemical sensor,40 the photo-responsive electrochemical sensor provides a 3



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more convenient operation way and is no need of external redox probes.

2. Experimental 2.1 Materials N,N,N’,N’’,N’’-Pentamethyldlethylenetrlamlne

(PMDETA

99%),

ethyl

α-bromoisobutyrate (99%), copper(I) bromide (99%), sodium hydroxide (NaOH), ethylene glycol dimethacrylate (EGDMA), N,N-dimethylaminopyridine (DMAP), N,N-dimethylformamide (DMF), triethylamine, phenol, sulfanilic acid, sodium nitrite, chitosan, methacrylic chloride, acrylic acid (AA), uric acid (UA), paracetamol (PCM), 4-nitrophenol (4-NP), 4-aminophenol (4-AP) were purchased from TCI. All of the reagents were analytical grade without further purification. All of aqueous solutions were prepared by using ultra-pure water (purified by 18.2 MU, Milli-Q, Millipore). 4-[(4-Methacryloyloxy) phenylazo] benzenesulfonic acid (MAPASA) was chosen as the photo-responsive functional monomer and prepared according to the Scheme 1.41 Typically, sulfanilic acid (3.00 g, 17.0 mmol) and K2CO3 (2.40 g, 17.0 mmol) were added in 10.0 mL of deionized water. When the above mixture was completely dissolved, 10.0 mL of NaNO2 (1.38 g, 20.0 mmol) aqueous solution was added dropwise to the mixture. The mixed solution was then cooled down to 0 oC by an ice-salt bath under constant stirring. After that 10.0 mL of 5 mol L−1 HCl was dropwise added to form a suspension. While maintaining the temperature of the suspension not greater than 3 oC, a white crystal of diazonium salt can be formed during the process. A 10.0 mL of phenol (1.63 g, 17.0 mmol) aqueous solution was then dropwise added into the resultant slurry after 1 h stirring in an ice-salt bath, making the slurry become brownish-orange. The slurry was further stirred in an ice-salt bath for another 3 h and then neutralized with 4.0 mol L−1 HCl. By washing with deionized water and drying over a freeze-drier after filtration, a crude product was obtained. After further recrystallization by mixing with extra 30.0 mL ethanol/H2O (5:1, v/v), 3.50 g of 4-[(4-Hydroxy) phenylazo] benzenesulfonic acid (PABSA) yellow powder is obtained (yielded 72.0%). 1H NMR (400 MHz, DMSO-d6) δ (ppm): 10.32 (s, 1H), 7.82 (d, J = 6.0 Hz, 2H), 7.77 (s, 4H), 6.96 (d, J = 5.6 Hz, 2H). 4


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MS: (negative mode) m/z: 277.0 (mass = 278.0 g mol–1). N,N-Dimethylaminopyridine (20 mg, 0.18 mmol), PABSA (3.00 g, 10.0 mmol), and triethylamine (1.52 g, 15.0 mmol) were added in 80 mL of acetonitrile. The above mixture was cooled down to 0 oC by an ice-salt bath. The methacrylic chloride (1.57 g, 15.0 mmol) in 7.0 mL of acetonitrile was added dropwise to the mixture under magnetic stirring. After the addition, the solution was heating up to 50 oC for 36 h and then cooled down to 25 oC for 2 h under constant stirring. By adding with saturated brine solution (50.0 mL) and filtration then washed with 3×15.0 mL of 4.0 mol L−1 HCl and drying over a freeze-drier, a crude product was obtained after. After further recrystallization by mixing with extra 20.0 mL ethanol/H2O (5:1, v/v), 2.60 g of orange crystals MAPASA was obtained (yielded 57.7%). 1H NMR (400 MHz, DMSO-d6) δ (ppm): 8.00 (d, J = 8.0 Hz, 2H), 7.80 - 7.88 (m, 4H), 7.44 (d, J = 8.0 Hz, 2H), 6.34 (s, 1H), 5.95 (s, 1H), 2.04 (s, 3H). MS (ESI): (negative mode) m/z: 345.0 (mass = 346.0 g mol–1).

Scheme 1. Synthesis route for MAPASA.

To prevent the Fe3O4 NPs aggregation, we used oleic acid to modify magnetic Fe3O4 nanoparticles (Fe3O4@OA) by a chemical coprecipitation method.42,43 Typically, 1.0 g of Fe3O4 NPs was mixed with 4.0 mL of oleic acid. The mixture was heated up to 80 oC for an hour and then cooled down to room temperature. The produced Fe3O4@OA NPs were washed repeatedly by water and ethanol with the aid of an external magnetic field. As shown in Scheme 2A, the nanosized photo-responsive MIPs (P-MIPs) were prepared using atom transfer radical polymerization (ATRP). In a 50 mL flask, 30 mg of Fe3O4@OA was dispersed in 5.0 mL of DMF and 5.0 mL of deionized water. After the above mixture ultrasonic stirring 15 min, PCM (10 mg, 69 µmol), MAPASA (80 mg, 227 µmol), and EGDMA (227 mg, 1.15 mmol) were introduced. Subsequently, the mixture was mechanical 5



stirring at 25 oC for 5 h in the dark. Under nitrogen atmosphere, 14.0 mg of CuBr (0.10 mmol), 20.0 uL of PMDETA (0.10 mmol), and 30.0 uL of ethyl α-bromoisobutyrate (0.15 mmol) were added into the mixture. Afterwards, the mixture was keep 65 oC for 12 h through mechanical stirring. Finally, the resulted PCM containing P-MIPs were collected by a magnet and dried at 40 oC for 24 h. In order to remove the template, PCM containing nanosized P-MIPs was washed with 200 mL of methanol:acetic acid (8:2) mixture for 48 h followed by 200 mL of methanol for 24 h in the dark. The completion of the PCM removal is optimized by UV-Vis spectral changes of PCM in the washing elution (Figure S1), where the PCM absorbance gradually decreases with the elution time suggesting the washing process is efficient to remove PCM from the nanosized P-MIPs matrix in total 72 h. The obtained nanosized P-MIPs were dried under vacuum at 50 oC. The photo responsive non imprinted polymer (P-NIPs) was also fabricated by the same manner without the PCM.

Scheme 2. (A) Synthesis route for P-MIPs and (B) P-MIPs/r-GO/MCGCE.

2.2 Instrumentation The chemical structure of MAPASA was characterized by 1H NMR spectrometer (AVANCE III HD 400 MHz, Bruker, Germany). Ultraviolet-Visible (UV-Vis) spectra were obtained on a spectrophotometer (UV-3900H, Hitachi, Japan). 365 nm and 440 nm lights were obtained by a CEL S-500 Xe light with 365nm and 440 nm filters, respectively. The morphology properties of materials were carried out on scanning electron microscopy (SEM; LEO1530VP, Zeiss, Germany) and transmission electron 6


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microscope (TEM; JEM-2100F, Japan). The magnetic properties of materials were characterized by vibrating specimen magnetometer (VSM, 7407, Lakeshore, USA). Thermal gravimetric analyses were performed on a simultaneous thermal analyzer (STA449 F3, NETZSCH, Germany). The X-ray diffractometer patterns were examined by XRD analyzer (D8-ADVANCE, Bruker, Germany). Fourier Transform infrared spectroscopy (FT-IR) was obtained via spectrometer (VERTEX 70 Bruker, Germany). High-performance liquid chromatography was conducted on a HPLC-UV Agilent 1100 apparatus (λ=254 nm, VP-ODSC18: 150 mm at 25 oC) with a mobile phase of methanol and water mixture (80:20). Electrochemical measurements of the sensor were recorded on a CHI660C electrochemical workstation (Chenhua, Shanghai, China), using a bare or modified magnetic-controlled glassy carbon electrode (MCGCE) working electrode, a platinum wire auxiliary electrode and a saturated calomel reference electrode (SCE). Cyclic voltammetry (CV) was recorded from - 0.2 V to + 0.6 V in a PBS buffer containing 5 mmol L-1 [Fe(CN)6]3-/4- and 0.1 mol L-1 KCl (scan rate: 50 mV s-1). Differential pulse voltammetry (DPV) was conducted for quantitative analysis basing on the variation of the oxidation peak current of PCM before and after being treated with PCM in a PBS buffer from + 0.1 V to + 0.6 V. 2.3 Preparation of photo-responsive MIPs magnetic sensor The P-MIPs magnetic electrochemical sensor was prepared as following steps shown in Scheme 2B: (i) prior to preparation of the P-MIPs sensor, a bare MCGCE with 3 mm diameter was polished with 0.3 µm as well as 0.05 µm alumina powder. Afterwards, washed with distilled water in an ultrasonic bath and dried under nitrogen atmosphere; (ii) r-GO powder was dispersed in 0.1 mol L−1 acetic acid containing 0.5 wt% chitosan to give 1 mg mL-1 r-GO suspension. Afterwards, 5.0 µL of r-GO suspension was coated on the MCGCE surface (r-GO/MCGCE) and dried at 25 oC; (iii) 20.0 mg of nanosized P-MIPs was dispersed into 10.0 mL distilled water by sonication for 30 min to form a homogeneous mixture. Then, 16.0 µL of the resulted suspension was dropped onto the r-GO/MCGCE and dried at 25 oC. For comparison, P-NIPs magnetic electrochemical sensor (P-NIPs/r-GO/MCGCE) was also fabricated following the same procedure. 7



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2.4 Spectroscopic characterization and photoregulated uptake and release studies The spectroscopic characterizations of monomer and material were performed with 0.2 mg mL-1 P-MIPs and 1.0 × 10-5 mol L-1 MAPASA PBS buffer and used air-tight screw-capped quartz cells with 1.0-cm optical path length. The sample was first irradiated at 365 nm and then at 440 nm. For

the

photoregulated

uptake

and

release

of

PCM

study,

the

P-MIPs/r-GO/MCGCE was first immersed into 0.7 mmol L-1 PCM PBS buffer solutions for 15 min. Non-specifically adsorbed samples was completely removed from the sensor by rinsing with PBS buffer and distilled deionized water and then the resulted sensor was transferred into a fresh PBS buffer solution for further electrochemical measurements. For the photo-regulated release of PCM, the PCM imprinted P-MIPs/r-GO/MCGCE was initially placed in a fresh PBS buffer solution in a quartz cell with 3.0 cm optical path and then irradiated by 365 nm light for 40 min. By contrast, the photo-regulated PCM uptake of P-MIPs/r-GO/MCGCE can be obtained by irradiating the electrode with a 440 nm light resource in 0.7 mmol L-1 PCM solutions. The following electrochemical measurements were all performed in a fresh PBS buffer solution. 2.5 Selectivity and application of the P-MIPs/r-GO/MCGCE The selectivity of P-MIPs/r-GO/MCGCE and P-NIPs/r-GO/MCGCE was studied by testing their binding capacities to PCM and analogs (4-NP, 4-AP, AA, and UA). P-MIPs/r-GO/MCGCE and P-NIPs/r-GO/MCGCE were incubated with 3.0 mL 0.7 mmol L-1 of PCM, 4-NP, 4-AP, AA, or UA solutions in PBS buffer for 15 min. The mixture was discarded. Fresh PBS was then added for electrochemical measurements. Human urine was collected from volunteer and subsequently centrifuged. The supernatant was filtered and diluted 100 times with PBS. The P-MIPs/r-GO/MCGCE was incubated in the urine sample in the dark for 15 min to rebind all the PCM from the urine sample. Non-specifically adsorbed samples was completely removed from the sensor by rinsing with PBS buffer and double distilled deionized water. The mixture was discarded. Fresh PBS was then added for electrochemical measurements. For the photo-extracting of PCM, the PCM imprinted P-MIPs/r-GO/MCGCE was 8


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initially placed in a fresh PBS buffer solution in a quartz cell with 3.0 cm optical path and then irradiated by 365 nm light for 40 min (cis). The mixture was discarded. Fresh PBS was then added for electrochemical measurements.

Results and discussion 3.1 Characterization The prepared Fe3O4, Fe3O4@OA, and nanosized P-MIPs were initially characterized by FT-IR spectra, which were displayed in Figure S2A. As expected, all three materials showed a significant feature of Fe-O stretching vibration at 564 cm-1 for Fe3O4. For OA modified Fe3O4 NPs, C=O asymmetric vibration of OA was observed at 1646 cm-1 when the carboxyl groups integrated with Fe atoms onto the Fe3O4 NPs.42,44 For nanosized P-MIPs, some extra features at 2955, 1729, 1247 and 1156 cm−1 can be attributed to C=O, C-H and C-O-C stretching vibrations in EGDMA, implying the successful formation of nanosized P-MIPs. The TGA results of the Fe3O4 (curve a), Fe3O4@OA (curve b), P-MIPs with Fe3O4@OA (curve c) and P-MIPs without Fe3O4@OA (curve d) were displayed in Figure S2B. For curve a, b, and c, 0.48%, 0.37%, 7.35% weight loss below 200 oC can be attributed to the removal of physically adsorbed water. For curve b, the 1.01% weight loss between 200 and 350 oC can be attributed to the decomposition of OA on the Fe3O4 surface. For curve c, 62.33% weight loss between 200 and 750 oC can be assigned to the decomposition of imprinted layer on the Fe3O4@OA surface. For curve d, about 98.21% weight loss above 750 oC, which was attributed to the decomposition of P-MIPs organic framework. The Figure S2C presents the X-Ray Diffraction spectra of Fe3O4 and P-MIPs. The six characteristic diffraction peaks of Fe3O4 (2θ=30.25, 35.77, 43.26, 53.59, 57.16, and 62.85o) were (220), (311), (400), (422), (511), and (440) were obtained for both samples. The nanocrystalline structure of Fe3O4 particles was confirmed by the broad diffraction peaks. Meanwhile, it demonstrates that the P-MIPs are composed of magnetite particles and it also indicates that the synthesis of P-MIP via ATRP did not alter the crystalline phase of magnetite particles. 9



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The magnetic hysteresis loops of Fe3O4, and nanosized P-MIPs were characterized by VSM and shown in Figure S2D. It is obvious that both samples display superparamagnetic characteristics. The saturation magnetization values of the Fe3O4 and P-MIPs were 52.63 and 28.74 emµ g-1, respectively. The intensity of magnetization of P-MIPs weakened was the results of the thin polymeric coating to shield the Fe3O4. These results prove that the P-MIPs were firmly immobilized on r-GO/MCGCE through magnetic force with the MCGCE. The morphologies of MCGCE, r-GO/MCGCE, and P-MIPs/r-GO/MCGCE were observed by SEM (Figure 1). The surface morphology of r-GO film showed the commonly crumple-like structure (Figure 1B) compared bare MCGCE (Figure 1A). Furthermore, nanosized P-MIPs were firmly attached to the surface of r-GO sheets on the MCGCE (Figure 1C). The morphologies of Fe3O4, nanosized P-MIPs and P-NIPs were also characterized by SEM (Figure 2(A-C)) and TEM (Figure 2(D-F)). The size of the Fe3O4 was about 100 nm in diameter with smooth surface and good size mono-disperse (Figure 2A, D). However, the diameter of the naosized P-MIPs and P-NIPs increases after surface imprinting (Figure 2E, F), and the surface became much rougher (Figure 2B, C). The images of Fe3O4, nanosized P-MIPs and P-NIPs high-angle

annular

dark-field

scanning

transmission

electron

microscopy

(HAADF-STEM) were shown in Figure S3, which were analyzed by scanning transmission electron microscopy energy dispersive spectroscopy (STEM-EDS). Compared with the images of HAADF-STEM, the STEM-EDS mapping of Fe, O, N, C exhibits a similar pattern. These results indicate that the elements of Fe, O, N, C are homogeneously distributed within the surface of P-MIP and P-NIPs. It could be concluded that the nanosized P-MIPs and P-NIPs have been prepared successfully on the surface of Fe3O4 via ATRP.

10


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Figure 1. SEM images of MCGCE (A), r-GO/MCGCE (B), and P-MIPs/r-GO/MCGCE (C).

Figure 2. SEM images of Fe3O4 (A), P-MIPs (B), and P-NIPs (C); TEM images of Fe3O4 (A), P-MIPs (B), and P-NIPs (C).

3.2 Electrochemical behavior of the P-MIPs/r-GO/MCGCE As shown in Figure S4A, DPV responses of a bare MCGCE and modified MCGCE were used to further confirm the formation of P-MIPs/r-GO/MCGCE. Using the [Fe(CN)6]3-/4- redox probe, compared with the bare MCGCE (curve a), an obvious increase of the peak current was obtained after the MCGCE was modified with r-GO (curve b). This is due to the good conductivity of r-GO. Afterward, modified with P-MIPs onto the r-GO/MCGCE electrode, the peak current of the probe decreased markedly (curve c), indicating the nanosized P-MIPs blocked the penetrating of the 11



redox probe. It also can be seen that r-GO and P-MIPs layer by layer coated onto the surface of MCGCE successfully. PCM can be electrochemically oxidized into N-acetyl-p-quinoneimine on a GCE, showing at about 356 mv.8 The DPV curve of P-MIPs/r-GO/MCGCE in the absence of PCM was recorded, in which no detectable peak was observed (Figure S4B, curve a), demonstrating the complete removal of PCM after elution. After incubation, an oxidation peak at around 356 mV was clearly recorded with the P-MIPs/r-GO/MCGCE (curve b). Since the electrochemical measurements were carried out in a PCM-free solution, the strong oxidation peak should be entirely attributed to the oxidation reaction of PCM molecules embedded into the imprinted sensor. In comparison, the P-NIPs/r-GO/MCGCE exhibits only a small signal response at 356 mV (curve c), which should be attributed to the non-specifically adsorbed toward the non-imprinted sensor. The higher response signal of imprinted sensor compared to that of non-imprinted sensor suggested that there were a large number of binding sites available in the imprinted sensor. 3.3 Photo-responsive behaviors of the P-MIPs/r-GO/MCGCE The photoisomerization properties of MAPASA and nanosized P-MIPs were investigated by UV-Vis spectroscopy upon alternated irradiation at 365 nm and 440 nm in PBS buffer, respectively. MAPASA typically exhibits a n → π* electron transition of N=N at 331 nm.25-27 Irradiating MAPASA at 365 nm caused the drop of this absorbance (Figure 3A), which is attributed to the trans → cis photoisomerization of azobenzene in MAPASA.33,45 Subsequently, the feature at 331 nm can be almost completely recovered when MAPASA irradiated at 440 nm and this observation suggests the reproduction of trans MAPASA (Figure 3B). By contrast, the azobenzene chromophores in MAPASA still perform the reversible photo driven trans →cis/cis → trans isomerization even in their rigid 3D crosslinked polymer network on the Fe3O4@OA surface (Figure 3C-D). However, within the same period, the degree of nanosized P-MIPs photoisomerization is less than that of MAPASA and this observation may suggest that the photoisomerization ability of the azobenzene chromophores is decreased due to the rigid polymer structure. 12


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Figure 3. Spectroscopic response upon the irradiation at 365 nm and 440 nm for MAPASA (1.0 × 10-5 mol L-1) (A, B) and P-MIPs (0.2 mg mL-1) (C, D).

Electrochemistry was performed to investigate the photo-responsive properties of the P-MIPs/r-GO/MCGCE sensor. Figure 4A represents the CV responses of the probe at the P-MIPs/r-GO/MCGCE upon irradiation at 365 nm and 440 nm in PBS buffer containing 5 mmol L-1 [Fe(CN)6]3-/4- and 0.1 mol L-1 KCl. After exposure to 365 nm for 40 min, the peak currents dramatically decreased (curve b) compared with that initial state (curve a). Subsequent irradiation at 440 nm caused the CV signal of the probe increased (curve c) and restored at nearly to its initial state. This process was totally reversible. Accordingly, the P-MIPs/r-GO/MCGCE can exhibit a stable photo ON–OFF switch property on account of its photo-responsive behavior with repeatable irradiation at 440 nm and 365 nm, respectively (Figure 4C). The results of CVs was also in consonance with observation on EIS (Figure 4B), where the charge transfer ability of the probe to the MCGCE surface can be indicated by the interfacial electron transfer resistance (ETR) and depends upon irradiation at 365 nm and 440 13



nm. This phenomenon is the consequence of the configurational change in the P-MIPs receptor sites. The cis form of azobenzene in MAPASA prevents the redox probe from reaching the electrode surface and results in a weaker CV response and higher interfacial ETR after the P-MIPs irradiated by 365 nm light resource. By contrast, the trans P-MIPs upon the irradiation at 440 nm seem with a less compact structure than the cis from. Thus, the trans P-MIPs allow the diffusion of the redox probe through the P-MIPs more accessible to the electrode surface with the evidences of stronger CV response and smaller interfacial ETR.

Figure 4. CV (A) and EIS (B) responses of the P-MIPs/r-GO/MCGCE before irradiation (curve a) and after 365 nm irradiation for 40 min (curve b) and subsequent irradiation at 440 nm for 40 min (curve c); (C) Variation of 356 mV Ipc of the P-MIPs/r-GO/MCGCE for the photo-switch between irradiation at 365 nm and 440 nm for three cycles.

3.4 Photo-regulated release and uptake of PCM by the P-MIPs/r-GO/MCGCE The adsorption time for the PCM extraction is an essential parameter to assess the property of P-MIPs sensor. Figure S5 shows the change of the peak current with 14


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different incubation time. It was found that the peak current of the PCM increased sharply in the first 15 min and then reached a steady-state current, which means that PCM have almost completely re-bound to the imprinting sites after 15 min. For P-NIPs/r-GO/MCGCE, there were no specific recognition sites, thus the PCM adsorbed on the P-NIPs/r-GO/MCGCE are less than P-MIPs/r-GO/MCGCE. This result was also illustrated by the nitrogen adsorption-desorption and shown in Table S1 and Figure S6. It can be seen that the pore volume, surface area, and average pore size of nanosized P-MIPs are larger than the P-NIPs. As the consequence of photo-regulated conformation changes under alternated irradiation at 365 nm and 440 nm, the processes of PCM release and uptake by the P-MIPs/r-GO/MCGCE is monitored upon PCM oxidation current by DPV method (Figure 5A) and the reversibility is revealed in Figure 5B. For P-MIPs/r-GO/MCGCE, the peak current of PCM was 3.88 µA after obtaining the rebinding equilibrium. The irradiation at 365 nm causes the release of the bound PCM into the solution with an obvious current decrease from 3.88 µA to 0.65 µA after 40 min, which is optimized as shown in Figure S7. The conformational changes of azobenzene are driven by the energy difference between the trans and cis forms,46,47,48 which has been confirmed by the electron density computations of trans and cis MAPASA isomers (Figure S10) and the resulted geometries further vary the hydrogen bonding abilities of the azonium protons.48 Taking them together, the release of PCM from P-MIPs/r-GO/MCGCE principally originates from the photoinduced trans → cis isomerization of MAPASA in the P-MIPs receptor sites, which disorders the initial conformation of the accepting cavities to PCM and as the consequence to potentially weaken hydrogen bonding interactions between the MAPASA and PCM. On the contrary, irradiation at 440 nm causes the uptake of PCM back into the P-MIPs/r-GO/MCGCE with the enhanced PCM oxidation current from 0.65 µA back to 3.76 µA after 40 min. At this time, the imprinting cavities for PCM in P-MIPs/r-GO/MCGCE are re-generated and the receptors enable to provide efficient hydrogen bonding sites to PCM in their trans forms. The photo-driven PCM release and uptake of P-MIPs/r-GO/MCGCE is highly efficient as the steady currents are quantitatively similar even after several irradiation 15



cycles. On the other hand, alternated irradiation on the P-NIPs/r-GO/MCGCE with 365 nm and 440 nm only shows negligible current changes upon the release and uptake of PCM under the same conditions to P-MIPs/r-GO/MCGCE.

Figure 5. (A) DPV of photo-regulated release and uptake of PCM using P-MIPs/r-GO/MCGCE; (B) DPV peak currents changes of PCM for the photo-regulated release and uptake between irradiation at 365 nm and 440 nm for three cycles using P-MIPs/r-GO/MCGCE. The concentration of PCM is 0.7 mmol L-1.

3.5 Selectivity, sensitivity and application of the P-MIPs/r-GO/MCGCE To assess the selectivity of P-MIPs/r-GO/MCGCE for PCM, AA and UA were chosen as the analogs due to they have similar oxidation potential to PCM. Besides, 4-NP and 4-AP were also chosen given structural similarity and electrochemical activity to PCM. As shown in Figure 6A, the current response of sensor towards PCM is much higher than the other analogs. By contrast, the current responses of the P-NIPs/r-GO/MCGCE for PCM and other species are quite similar.

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Figure 6. (A) The selectivity of P-MIPs/r-GO/MCGCE and P-NIPs/r-GO/MCGCE for PCM, 4-AP, 4-NP, AA and UA in PBS buffers. The concentration of PCM or its analogs is 0.7mmol L-1; (B) DPV peak currents changes of PCM with different concentrations recorded on the P-MIPs/r-GO/MCGCE alternated irradiation at 365 nm (▲) and 440 nm (■). PCM concentrations: 0.001, 0.01, 0.07, 0.15, 0.3, 0.5, 0.7, 2, 5, 7 mmol L-1; (C) Calibration curves corresponding to the response recorded on the P-MIPs/r-GO/MCGCE and P-NIPs/r-GO/MCGCE versus the concentration of PCM.

The reusability and PCM sensing ability of P-MIPs/r-GO/MCGCE have been demonstrated in Figure 6B. A single P-MIPs/r-GO/MCGCE was employed for the continuous determination of PCM samples with diverse concentrations, where the determinations was conducted upon the irradiation at 440 nm and the self-cleaning process of the sensor was achieved with 365 nm irradiation. In particular, the oxidation peak currents of PCM by DPV increase with the increment of PCM concentrations ranging from 0.001 to 7 mmol L-1 on the sensor (Figure S8). To eliminate the effect of residual current after each self-cleaning process, the current difference between PCM uptake and release was utilized to prepare the calibration curve. The calibration curve in Figure 6C reveals that the peak currents were proportional to the concentrations of PCM in two segments and demonstrated linear regression equations as ∆I (µA) = 0.481 + 0.005C[PCM] (R2 = 0.96) (0.001-0.7 mmol L-1) and ∆I (µA) = 3.6 + 0.0005C[PCM]. (R2 = 0.95) (0.7-7 mmol L-1), respectively, with a favorable quantification limit of 0.00086 mmol L-1 and a detection limit of 0.00043 mmol L-1. By contrast, the response of the P-NIPs/r-GO/MCGCE were not 17



sensitive to PCM and stayed at relatively low values within the whole testing range, which is due to the lack of affinity. The LOD and LOQ were calculated using 3σ/slope and 10σ/slope ratios, respectively; where σ is the standard deviation of the blank response which is obtained from 20 replicate measurements of the blank PBS buffer solution. The measured DPV curve matrix at the LOD level is shown in Figure S9. The reliability of this calibration curve has been evaluated by RSDs of intra-day and inter-day tests (Table S2),49,50,51 where urine samples with different concentrations (0.3, 1.0, 3.0 mmol L-1) were measured (four measurements on each sample) according the calibration curve in one day and over three days. It shows that the calibration curve has enough precision as expected and is available for the PCM detection in practice. Additionally, we compared the sensing performance of P-MIPs with other reported MIP sensors for PCM determination. The P-MIP sensor presents acceptable detection limit as well as a wide linear dynamic range shown in Table S3. It should be noted that the P-MIPs/r-GO/MCGCE is not only used as an environmental, reliable, and effective sensing platform for PCM, but also provides a light-driven functionality of extraction, which is not achieved by other previously reported PCM sensors. The P-MIPs/r-GO/MCGCE was used as a solid absorbent for the extraction and sensing of PCM from human urine samples (Scheme 3). Human urine was collected from a healthy volunteer and each urine sample was added with required amount of PCM. The results have been concluded in Table S4. As shown, the recoveries of PCM in the urine as determined by P-MIPs extraction were varied between 87.5% - 93.3%, which were in a good line with those obtained by the traditional HPLC method. It implied that the sensor we prepared can be used as an environmental, reliable, and effective sensing platform for extracting and detecting trace PCM in biological samples.

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Scheme 3. Photo-controlled PCM extraction from a human urine sample.

4. Conclusions In summary, a sensitive and selective P-MIPs electrochemical sensor was developed. Basing on a configurational change of azobenzene in the P-MIPs receptor sites upon programmed 365/440 nm light exposure, the proposed sensor exhibited an excellent capability of light-driven reversible release and uptake PCM. These properties provided efficient photo-controlled extraction of PCM from biological samples with good sensitivity, high selectivity, and reproducibility. This work also offer a promising supplementary for stimuli-responsive MIPs sensing applications in particular, through an electrochemical approach. However, the P-MIPs sensors require relatively long time for photo driven sample release and uptake and it may probably limit the detection efficiency in their practical applications.

Associated content Supporting Information UV-Vis spectral changes of PCM in the washing elution with different elution time (Figure S1); FT-IR spectra, TGA curves, XRD patterns, and Hysteresis loops of Fe3O4 and imprinted materials (Figure S2); HAADF and TEM-EDS images of Fe3O4 and materials (Figure S3); DPV responses of bare MCGCE and modified MCGCE (Figure S4); peak currents of PCM recorded on the P-MIPs/r-GO/MCGCE and P-NIPs/r-GO/MCGCE incubated in 0.7 mmol L-1 PCM for different incubation times 19



(Figure S5); isotherms and pore distribution of P-MIPs and P-NIPs (Figure S6); peak currents of PCM removal from PCM imprinted P-MIPs/r-GO/MCGCE under different 365 nm irradiation times (Figure S7); DPV of PCM at P-MIPs/r-GO/MCGCE. PCM concentration: 0.001, 0.01, 0.07, 0.15, 0.3, 0.5, 0.7, 2, 5, 7 mmol L-1 (Figure S8); the matrix DPV curve at the LOD level (Figure S9); electron density surfaces for the trans and cis isomers of MAPASA with the |LUMO|, |HOMO|, |HOMO-1|, |HOMO-2| and |HOMO-3| (Figure S10). The Supporting Information is available free of charge on the ACS Publications website.

Acknowledgements This work was financially supported by the National Natural Science Foundation of China (Grant Nos. 21475046, 21427809, 21645004). We also acknowledge the State Key Laboratory of Pulp and Paper Engineering (201623) and Fundamental Research Funds for the Central Universities (No. 2015ZP028, 2017MS094).

Author information Corresponding Authors *E-mail: [email protected] (Qiang Zeng) *E-mail: [email protected] (Lishi Wang) Notes The authors declare no competing financial interest.

References (1) Carvalho, R. M. D.; Freire, R. S.; Rath, S.; Kubota, L. T. Effects of EDTA on Signal Stability During Electrochemical Detection of Acetaminophen. J. Pharm. Biomed. Anal. 2004, 34, 871-878. (2) Kachoosangi, R. T.; Wildgoose, G. G.; Compton, R. G. Sensitive Adsorptive Stripping Voltammetric Determination of Paracetamol at Multiwalled Carbon Nanotube Modified Basal Plane Pyrolytic Graphite Electrode. Anal. Chim. Acta 2008, 618, 54-60. (3) Celma, C.; Allué, J. A.; Pruñonosa, J.; Peraire, C.; Obach, R. Simultaneous Determination of 20


Page 20 of 25

Page 21 of 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


Paracetamol and Chlorpheniramine in Human Plasma by Liquid Chromatography-Tandem Mass Spectrometry. J. Chromatogr. A 2000, 870, 77-86. (4) Knochen, M.; Giglio, J.; Reis, B. F. Flow-injection Spectrophotometric Determination of Paracetamol in Tablets and Oral Solutions. J. Pharm. Biomed. Anal. 2003, 33, 191-197. (5) Dinc, E.; Onur, F. Application of a New Spectrophotometric Method for the Analysis of a Ternary Mixture Containing Metamizol, Paracetamol and Caffeine in Tablets. Anal. Chim. Acta 1998, 359, 93-106. (6) Easwaramoorthy, D.; Yu, Y. C.; Huang, H. J. Chemiluminescence Detection of Paracetamol by a Luminol-Permanganate Based Reaction. Anal. Chim. Acta 2001, 439, 95-100. (7) Kang, X.; Wang, J.; Wu, H.; Liu, J.; Aksay, I. A.; Lin, Y. A. Graphene-Based Electrochemical Sensor for Sensitive Detection of Paracetamol. Talanta 2010, 81, 754-759. (8) Luo, J.; Ma, Q.; Wei, W.; Zhu, Y.; Liu, R.; Liu, X. Synthesis of Water-Dispersible Molecularly Imprinted Electroactive Nanoparticles for the Sensitive and Selective Paracetamol Detection. ACS Appl. Mater. Interfaces 2016, 8, 21028-21038. (9) Teng, Y.; Fan, L.; Dai, Y.; Zhong, M.; Lu, X.; Kan, X. Electrochemical Sensor for Paracetamol Recognition and Detection Based on Catalytic and Imprinted Composite Film.

Biosens. Bioelectron. 2015, 71, 137-142. (10)

Luo, J.; Cong, J.; Fang, R.; Fei, X.; Liu, X. One-Pot Synthesis of a Graphene Oxide

Coated with an Imprinted Sol-Gel for use in Electrochemical Sensing of Paracetamol. Microchim.

Acta 2014, 181, 1257-1266. (11)

Chen, L.; Wang, X.; Lu, W.; Wu, X.; Li, J. Molecular Imprinting: Perspectives and

Applications. Chem. Soc. Rev. 2016, 45, 2137-2211. (12)

Ma, Y.; Shen, X. L.; Wang, H. S.; Tao, J.; Huang, J. Z.; Zeng, Q.; Wang, L. S.

MIPs-graphene Nanoplatelets-MWCNTs Modified Glassy Carbon Electrode for the Determination of Cardiac Troponin I. Anal. Biochem. 2017, 520 (1), 9-15. (13)

Ma, Y.; Shen, X. L.; Zeng, Q.; Wang, H. S.; Wang, L. S. A Multi-walled Carbon

Nanotubes Based Molecularly Imprinted Polymers Electrochemical Sensor for the Sensitive Determination of HIV-p24. Talanta. 2017, 164 (1), 121-127. (14)

Wackerlig, J.; Lieberzeit, P. A. Molecularly Imprinted Polymer Nanoparticles in

Chemical Sensing-Synthesis, Characterisation and Application. Sens. Actuators B 2015, 207, 144-157. (15)

Orozco, J.; Cortés, A.; Cheng, G.; Sattayasamitsathit, S.; Gao, W.; Feng, X.; Shen, Y.;

Wang, J. Molecularly Imprinted Polymer-Based Catalytic Micromotors for Selective Protein Transport. J. Am. Chem. Soc. 2013, 135 (14), 5336-5339. (16)

Culver, H. R.; Clegg, J. R.; Peppas, N. A. Analyte-Responsive Hydrogels: Intelligent

Materials for Biosensing and Drug Delivery. Acc. Chem. Res. 2017, 50 (2), 170-178. (17)

Terzopoulou, Z.; Papageorgiou, M.; Kyzas, G. Z.; Bikiaris, D. N.; Lambropoulou, D. A. 21



Preparation of Molecularly Imprinted Solid-Phase Microextraction Fiber for the Selective Removal and Extraction of the Antiviral Drug Abacavir in Environmental and Biological Matrices.

Anal. Chim. Acta 2016, 913, 63-75. (18)

Xie, X.; Chen, L.; Pan, X.; Wang, S. Synthesis of Magnetic Molecularly Imprinted

Polymers by Reversible Addition Fragmentation Chain Transfer Strategy and Its Application in the Sudan Dyes Residue Analysis. J. Chromatogr. A 2015, 1405, 32-39. (19)

Li, Z.; Quan, H.; Gong, C.; Yang, Y.; Tang, Q.; Wei, Y.; Ma, X.; Lam, H. W.

Photocontrolled Solid-Phase Extraction of Guanine From Complex Samples Using a Novel Photoresponsive Molecularly Imprinted Polymer. Food Chem. 2015, 172, 56-62. (20)

Peng, H.; Luo, M.; Xiong, H.; Yu, N.; Ning, F.; Fan. J.; Zeng, Z.; Li, J.; Chen, L.

Preparation of Photonic-Magnetic Responsive Molecularly Imprinted Microspheres and Their Application to Fast and Selective Extraction of 17-Estradiol. J. Chromatogr. A 2016, 1442, 1-11. (21)

Xu, S.; Lu, H.; Zheng, X.; Chen, L. Stimuli-Responsive Molecularly Imprinted

Polymers: Versatile Functional Materials. J. Mater. Chem. C 2013, 1, 4406-4422. (22)

Fertier, L.; Théron, C.; Carcel, C.; Trens, P.; Man, M. W. C. pH-Responsive Bridged

Silsesquioxane. Chem. Mater. 2011, 23, 2100-2106. (23)

Li, S. J.; Pilla, S.; Gong, S. Q. Modulated Molecular Recognition by a Temperature

Sensitive Molecularly-Imprinted Polymer. J. Polym. Sci. A 2009, 47, 2352-2360. (24)

Pan, G.; Guo, Q.; Ma, Y.; Yang, H.; Li, B. Thermo-Responsive Hydrogel Layers

Imprinted with RGDS Peptide: a System for Harvesting Cell Sheets. Angew. Chem. Int. Ed. 2013, 52, 6907-6911. (25)

Gong, C. B.; Wei, Y. B.; Liu, L. T.; Zheng, A. X.; Yang, Y. H.; Chow, C. F.; Tang, Q.

Photoresponsive Hollow Molecularly Imprinted Polymer for Trace Triamterene in Biological Samples. Mater. Sci. Eng. C 2017, 76, 568-578. (26)

Tang, Q.; Li, Z.; Wei, Y.; Yang, X.; Liu, L.; Gong, C.; Ma, X.; Lam, M. H. W.; Chow, C.

Photoresponsive Surface Molecularly Imprinted Polymer on ZnO Nanorods for Uric Acid Detection in Physiological Fluids. Mater. Sci. Eng. C 2016, 66, 33-39. (27)

Wei, Y.; Tang, Q.; Gong, C.; Lam, M. H. W. Review of the Recent Progress in

Photoresponsive Molecularly Imprinted Polymers Containing Azobenzene Chromophores. Anal.

Chim. Acta 2015, 900, 10-20. (28)

Zhao, M.; Zhang, C.; Zhang, Y.; Guo, X.; Yan, H.; Zhang, H. Efficient Synthesis of

Narrowly Dispersed Hydrophilic and Magnetic Molecularly Imprinted Polymer Microspheres with Excellent Molecular Recognition Ability in a Real Biological Sample. Chem. Commun. 2014, 50, 2208-2210. (29)

Fang, L.; Chen, S.; Zhang, Y.; Zhang, H. Azobenzene-Containing Molecularly Imprinted

Polymer Microspheres with Photoresponsive Template Binding Properties. J. Mater. Chem. 2011, 21, 2320-2329. (30)

Kim, M.; Safron, N. S.; Huang, C.; Arnold, M. S.; Gopalan, P. Light-Driven Reversible 22


Page 22 of 25

Page 23 of 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


Modulation of Doping in Graphene. Nano Lett. 2012, 12, 182-187. (31)

Loudwig, S.; Bayley, H. Photoisomerization of an Individual Azobenzene Molecule in

Water: An On-Off Switch Triggered by Light at a Fixed Wavelength. J. Am. Chem. Soc. 2006, 128, 12404-12405. (32)

Paoprasert, P.; Park, B.; Kim, H.; Colavita, P.; Hamers, R. J.; Evans, P. G.; Gopalan, P.

Dipolar Chromophore Functional Layers in Organic Field Effect Transistors. Adv. Mater. 2008, 20, 4180-4184. (33)

Ercole, F.; Davis, T. P.; Evans, R. A. Photo-Responsive Systems and Biomaterials:

Photochromic Polymers, Light-Triggered Self-Assembly, Surface Modification, Fluorescence Modulation and Beyond. Polym. Chem. 2010, 1, 37-54. (34)

Yang, G.; Zhao, F.; Zeng, B. Magnetic Entrapment for Fast and Sensitive Determination

of Metronidazole with a Novel Magnet-Controlled Glassy Carbon Electrode. Microchim. Acta 2014, 135, 154-160. (35)

Zamora-Gálvez, A.; Ait-Lahcen, A.; Mercante, L. A.; Morales-Narváez, E.; Amine, A.;

Merkoҁi, A. Molecularly Imprinted Polymer-Decorated Magnetite Nanoparticles for Selective Sulfonamide Detection. Anal. Chem. 2016, 88, 3578-3584 (36)

Lahcen, A. A.; Baleg, A. A.; Baker, P.; Iwuoha, E.; Amine, A. Synthesis and

Electrochemical Characterization of Nanostructured Magnetic Molecularly Imprinted Polymers for 17-β-Estradiol Determination. Sens. Actuators B 2017, 241, 698-705. (37)

Fang, L.; Chen, S.; Guo, X.; Zhang, Y.; Zhang, H. Azobenzene-Containing Molecularly

Imprinted Polymer Microspheres with Photo- and Thermoresponsive Template Binding Properties in Pure Aqueous Media by Atom Transfer Radical Polymerization. Langmuir 2012, 28, 9767-9777. (38)

Hawker, C. J.; Bosman, A. W.; Harth, E. New Polymer Synthesis by Nitroxide Mediated

Living Radical Polymerizations. Chem. Rev. 2001, 101, 3661-3688. (39)

Zhang, H. Controlled/‘‘living’’ Radical Precipitation Polymerization: A Versatile

Polymerization Technique for Advanced Functional Polymers. Eur. Polym. J. 2013, 49, 579-600. (40)

Wei, Y.; Zeng, Q.; Hu, Q.; Wang, M.; Tao, J.; Wang, L. Self-cleaned Electrochemical

Protein Imprinting Biosensor Basing on a Thermo-Responsive Memory Hydrogel. Biosens.

Bioelectron. 2018, 99, 136-141. (41)

Gong, C.; Wong, K. L.; Lam, M. H. W. Photoresponsive Molecularly Imprinted

Hydrogels for the Photoregulated Release and Uptake of Pharmaceuticals in the Aqueous Media.

Chem. Mater. 2008, 20, 1353-1358. (42)

Li, D.; Jiang, D.; Chen, M.; Xie, J.; Wu, Y.; Dang, S.; Zhang, J. An Easy Fabrication of

Monodisperse Oleic Acid-Coated Fe3O4 Nanoparticles. Mater. Lett. 2010, 64, 2462-2464. (43)

Xu, S.; Li, J.; Song, X.; Liu, J.; Lu, H.; Chen, L. Photonic and Magnetic Dual

Responsive Molecularly Imprinted Polymers: Preparation, Recognition Characteristics and Properties as a Novel Sorbent for Caffeine in Complicated Samples. Anal. Methods 2013, 5, 23



124-133. (44)

Lan, Q.; Liu, C.; Yang, F.; Liu, S.; Xu, J.; Sun, D. Synthesis of Bilayer Oleic

Acid-Coated Fe3O4 Nanoparticles and Their Application in pH-Responsive Pickering Emulsions. J.

Colloid Interface Sci. 2007, 310, 260-269. (45)

Goulet-Hanssens, A.; Barrett, C. J. Photo-Control of Biological Systems with

Azobenzene Polymers. Polym. Chem. 2013, 51, 3058-3070. (46)

Beharry, A. A.; Woolley, G. A. Azobenzene photoswitches for biomolecules. Chem. Soc.

Rev. 2011, 40, 4422-4437 (47)

Fehrentz, T.; Schӧnberger, M.; Trauner, D. Optochemical Genetics. Angew. Chem., Int.

Ed. 2011, 50, 12156-12182 (48)

Samanta, S.; McCormick, T. M.; Schmidt, S. K.; Seferos, D. S.; Woolley, G. A. Robust

Visible Light Photoswitching with Ortho-thiol Substituted Azobenzenes. Chem. Commun. 2013, 49, 10314-10316. (49)

Arabi, M.; Ostovan, A.; Ghaedi, M.; Purkait, M. K. Novel Strategy for Synthesis of

Magnetic Dummy Molecularly Imprinted Nanoparticles based on Functionalized Silica as an Efficient Sorbent for the Determination of Acrylamide in Potato Chips: Optimization by Experimental Design Methodology. Talanta 2016, 154, 526–532. (50)

Ostovan, A.; Ghaedi, M.; Arabi, M.; Asfaram, A. Hollow Porous Molecularly Imprinted

Polymer for Highly Selective Clean-up followed by Influential Preconcentration of Ultra-Trace Glibenclamide from Bio-Fluid. J. Chromatogr. A 2017, 1520, 65-74. (51)

Bagheri, H.; Molaei, K.; Asgharinezhad A. A.; Ebrahimzadeh, H.; Shamsipur, M.

Magnetic Molecularly Imprinted Composite for the Selective Solid-Phase Extraction of

p-aminosalicylic Acid followed by High-Performance Liquid Chromatography with Ultraviolet Detection. J. Sep. Sci. 2016, 39, 4166-4174.

Graphical abstract

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Nanosized Difunctional Photo Responsive Magnetic Imprinting

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