Molecularly Imprinted Polymer Sensor Research Articles

Fabrication of a molecularly imprinted silylated graphene oxide polymer for sensing and quantification of creatinine in blood and urine samples

A graphene oxide (GO)-based electrochemical sensor, trimethyl silane propyl methacrylate-GO copolymerized with 2-hydroxymethacrylate/methyl methacrylate [TMSPMA-GO-co-HEMA/MMA], to detect creatinine (Cn) was fabricated by molecular imprinting technology followed by electrochemical detection. Electrochemical measurements were made by cyclic voltammetry and differential pulse voltammetry. Polymerization of GO-TMSPMA was achieved in the presence of Cn with ethylene glycol dimethacrylate as crosslinker and 2,2′-azobisisobutyronitrile as initiator. The physical and chemical properties of the resulted material were characterized by FTIR spectroscopy, NMR spectroscopy, Raman spectroscopy, XRD, SEM, and AFM. The effective pH for the response of the sensor material was found to be 7.4. The electrode exhibited a response time of ∼2 min, and the limit of detection obtained was 0.1878 mg/dL and the limit of quantification was 0.6122 mg/dL. The fabricated molecular imprinted polymer sensor could be reused several times without decrease in its selectivity. The feasibility of the present sensor in real time was successfully verified by analyzing Cn level in human blood serum and urine samples. By comparing the present sensing method with the traditional Jaffe method, we obtained a linear correlation with a coefficient of 0.9928; this implies that the present biosensor possesses a sensitivity comparable to that of the traditional laboratory method.

Metal-organic framework-based molecularly imprinted polymer as a high sensitive and selective hybrid for the determination of dopamine in injections and human serum samples

A highly sensitive and selective molecular imprinting polymer (MIP) sensor was fabricated based on polypyrrole (PPy)/ZIF-67/Nafion hybrid modified glassy carbon electrode (GCE) for the determination of dopamine (DA). The ZIF-67 material was facilely prepared by using hydrothermal synthesis method; subsequently, the PPy/ZIF-67/Nafion hybrid was obtained through a one-pot synthesis method. The physical properties of the materials and the modified sensors were investigated by using X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Nitrogen adsorption-desorption isothermal (BET), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM) and Atomic force microspectroscopy (AFM) apparatus. Cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscope (EIS) were used to evaluate the electrochemical performance of the sensors. The influence factors controlling the performance of the MIP sensor were studied and included scan rate, pH value and scan cycles. Under optimal conditions, DPV peak was linearly related to DA concentration over two concentration intervals (0.08–100 µM and 100–500 µM). The detection limit of PPy/ZIF-67-MIPs/Nafion/GCE sensor for DA was 0.0308 µM (S/N = 3) and sensitivity was equal to 1.656 µA µM cm−2. Furthermore, good reproducibility, long-term stability and favorable selectivity were obtained in the experiment. Moreover, the fabricated MIP sensor was successfully applied in the determination of DA concentrations in injection and human serum samples with satisfactory recoveries.

Breast cancer biomarker (HER2-ECD) detection using a molecularly imprinted electrochemical sensor

The extracellular domain of the human epidermal growth factor receptor 2 (HER2-ECD) is a protein breast cancer biomarker. Its quantification in peripheral blood could provide an important contribution to diagnostics and patient follow-up. In this work an electrochemical molecularly imprinted polymer (MIP) sensor for the quantification of HER2-ECD was developed. The MIP was electropolymerized by cyclic voltammetry using a solution containing phenol and HER2-ECD on a screen-printed gold electrode (AuSPE). The sensor was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The analysis of HER2-ECD was performed by differential pulse voltammetry using ([Fe(CN)6]3−/4−as redox probe. The linear range was established in the concentration interval from 10 to 70 ng/mL HER2-ECD, with a limit of detection of 1.6 ng/L and a limit of quantification of 5.2 ng/mL. Through the analysis of other protein biomarkers, the MIP sensor was found to be selective. Furthermore, these proteins did not interfere in the analysis of the selected biomarker. The developed sensor was used for the analysis of spiked human serum samples, providing adequate recovery values and precise results. The outcomes of this study indicate that the developed MIP sensor could be useful in the non-invasive analysis of HER2-ECD in breast cancer patients.

Development of a molecularly imprinted polymer-based electrochemical sensor for tyrosinase

For the first time a molecularly imprinted polymer (MIP)-based sensor for tyrosinase is described. This sensor is based on the electropolymerization of scopoletin or o-phenylenediamine in the presence of tyrosinase from mushrooms, which has a high homology to the human enzyme. The template was removed either by treatment with proteinase K or by alkaline treatment. The measuring signal was generated either by measuring the formation of a product by the target enzyme or by evaluation of the permeability of the redox marker ferricyanide. The o-phenylenediamine-based MIP sensor has a linear measuring range up to 50 nM of tyrosinase with a limit of detection of 3.97 nM (R$^{2}$ = 0.994) and shows good discrimination towards other proteins, e.g., bovine serum albumin and cytochrome c.

A screen-printed carbon electrode modified with gold nanoparticles, poly(3,4-ethylenedioxythiophene), poly(styrene sulfonate) and a molecular imprint for voltammetric determination of nitrofurantoin.

A molecularly imprinted polymer (MIP) and a nanocomposite prepared from gold nanoparticles (AuNP) and poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT:PSS) were deposited on a screen-printed carbon electrode (SPCE). The nanocomposite was prepared by one-pot simultaneous in-situ formation of AuNPs and PEDOT:PSS and was then inkjet-coated onto the SPCE. The MIP film was subsequently placed on the modified SPCE by co-electrodeposition of o-phenylenediamine and resorcinol in the presence of the antibiotic nitrofurantoin (NFT). Using differential pulse voltammetry (DPV), response at the potential of ~ 0.1V (vs. Ag/AgCl) is linear in 1nM to 1000nM NFT concentration range, with a remarkably low detection limit (at S/N = 3) of 0.1nM. This is two orders of magnitude lower than that of the control MIP sensor without the nanocomposite interlayer, thus showing the beneficial effect of AuNP-PEDOT:PSS. The electrode is highly reproducible (relative standard deviation 3.1% for n = 6) and selective over structurally related molecules. It can be re-used for at least ten times and was found to be stable for at least 45days. It was successfully applied to the determination of NFT in (spiked) feed matrices and gave good recoveries. Graphical abstract Schematic representation of a voltammetric sensor for the determination of nitrofurantoin. The sensor is based on a screen-printed carbon electrode (SPCE) modified with an inkjet-printed gold nanoparticles-poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) nanocomposite and a molecularly imprinted polymer.

Electrochromic Molecular Imprinting Sensor for Visual and Smartphone-Based Detections.

Electrochromic effect and molecularly imprinted technology have been used to develop a sensitive and selective electrochromic sensor. The polymeric matrices obtained using the imprinting technology are robust molecular recognition elements and have the potential to mimic natural recognition entities with very high selectivity. The electrochromic behavior of iridium oxide nanoparticles (IrOx NPs) as physicochemical transducer together with a molecularly imprinted polymer (MIP) as recognition layer resulted in a fast and efficient translation of the detection event. The sensor was fabricated using screen-printing technology with indium tin oxide as a transparent working electrode; IrOx NPs where electrodeposited onto the electrode followed by thermal polymerization of polypyrrole in the presence of the analyte (chlorpyrifos). Two different approaches were used to detect and quantify the pesticide: direct visual detection and smartphone imaging. Application of different oxidation potentials for 10 s resulted in color changes directly related to the concentration of the analyte. For smartphone imaging, at fixed potential, the concentration of the analyte was dependent on the color intensity of the electrode. The electrochromic sensor detects a highly toxic compound (chlorpyrifos) with a 100 fM and 1 mM dynamic range. So far, to the best of our knowledge, this is the first work where an electrochromic MIP sensor uses the electrochromic properties of IrOx to detect a certain analyte with high selectivity and sensitivity.

Development of a novel electrochemical sensor based on electropolymerized molecularly imprinted polymer for selective detection of sodium lauryl sulfate in environmental waters and cosmetic products

In this study, a novel molecularly imprinted polymer (MIP) sensor for the electrochemical detection of sodium lauryl sulfate (SLS) is reported. The MIP based screen-printed gold electrode (Au-SPE) was prepared by an electrochemical polymerization of 2-aminothiophenol (2-ATP) in the presence of SLS as target molecule. For control, a non-imprinted polymer (NIP) sensor was also constructed identically by omitting the SLS template. Moreover, the selectivity of the proposed MIP sensor was investigated by using analogues such as Ethylenediaminetetraacetic acid (EDTA), Tween 80 and Urea, revealing satisfactory selectivity toward SLS. The electrochemical characterization of the elaborated sensor was performed using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) techniques. The morphology of the MIP sensor was studied by means of Atomic Force Microscopy (AFM) and Fourier Transform Infrared Spectroscopy (FTIR) methods. Some experimental parameters such as number of cycle for the electropolymerization, incubation time of 2-ATP, elution and SLS incubation time, were optimized to improve the sensor performances. Under optimal conditions, the electrochemical sensor exhibits a logarithmic working range from 0.1 to 1000 pg/mL, and a detection limit of 0.18 pg/mL. Additionally, compared with reported works, the sensor possesses remarkable properties, such as a higher sensitivity and selectivity, a good reproducibility, a wider logarithmic range, a lower detection limit and a long-term stability. As real application, the developed MIP sensor was well employed to determine SLS contents in environmental waters and cosmetic products samples. A UV–vis spectrophotometer was used as reference method. A partial least squares (PLS) technique was well employed to study the correlation between the spectrophotometer and the MIP sensor technology with a satisfactory regression coefficient (R = 0.99). The obtained results during the sensor development and applications suggested an interesting and valuable tool for environmental analysis.

Molecularly imprinted sensor based on Russian Matryoshka structured molecules for enhanced specific identification and double amplification in ultra-trace Tb3+ determination

The selective and sensitive detection of rare earth elements is thought to be difficult because the concentration of those elements in the sample is commonly at a low level and they normally have severe mutual interference which is caused by homologous chemical properties. In this study, a novel molecularly imprinted polymer (MIP) sensor was fabricated for highly sensitive and selective determination of ultra-trace Tb3+. The Tb3+-ethylenediaminetetraacetic acid complex (Tb-EDTA) as the template molecule was incorporated into mono-6-mercapto-β-cyclodextrin (mono-6-SH-β-CD) to form a Russian Matryoshka (RM)-structured molecule (CD/Tb-EDTA). Titanium isopropoxide was utilized in vapor sol–gel polymerization to construct MIP membrane. Moreover, the selectivity of the RM MIP sensor was remarkably enhanced by the “triple-selectivity” recognition of EDTA-to-Tb3+, β-CD-to-(Tb-EDTA), and 3D cavity-to-(CD/Tb-EDTA), while the sensitivity of the MIP sensor was significantly improved by ECL signal enhancement based on double amplification, in other words, the electrochemiluminescence resonance energy transfer (ECL-RET) between the ECL donor of CD/Tb-EDTA and the ECL acceptor of Ru(bpy)32+, and the ECL enhancement by the co-reactant of CD/Tb-EDTA on Ru(bpy)3Cl2. When the imprinted cavities were occupied by Tb-EDTA during rebinding, the host-guest inclusion structured complex was formed and the ECL intensities produced by the Ru(bpy)3Cl2 ECL system increased with increasing concentration of Tb-EDTA. The proposed sensor was used for quantitative analysis of Tb3+ with concentrations ranging from 8.00 × 10–13 mol/L to 4.00 × 10–9 mol/L and successfully applied to detect Tb3+ in seawater samples. The detection limit of the sensor was found to be 3.90 × 10–13 mol/L (DL = 3δb/K), which is lower than previously reported values. Thus, the fabricated sensor is feasible for practical applications.

Electrochemical impedance sensor for herbicide alachlor based on imprinted polymer receptor

Alachlor (ALA), a carcinogenic herbicide is detected in surface and groundwater, as well as in milk, eggs, and meat. So, the sensitive detection of ALA is essential for humans. To respond, we report a molecularly imprinted polymer (MIP) receptor for simple electrochemical sensing of ALA. The MIP film was immobilized onto glassy carbon electrode by electrodeposition of o‑phenylenediamine (o‑PD) in the presence of ALA as a template, followed by the ALA leaching out to create specific recognition cavities to ALA. The stepwise fabrication of the sensor was characterized by recording cyclic, square wave voltammetry peak currents and the electron transfer resistance (Ret) where the [Fe(CN)6]3−/4− was used as an electro-active probe. The mole ratio of ALA to o‑PD as well as the controlled release of the alachlor from the MIP‑o‑PD network was optimized to create a maximum number of free imprinted sites that affected the sensor sensitivity and its linear range. The increment in the Ret of the redox probe [Fe(CN)6]3−/4− upon selective recognition of ALA to the free cavities of MIP film is employed as the sensor response. At the optimal experimental conditions, the relative change in Ret is linearly correlated to the ALA concentrations in a range of 1 nM to 1 μM ALA. This sensor shows the high sensitivity of ALA with a limit of detection of 0.78 nM ALA. The affinity of MIP to ALA is proved by calculating the dissociation constant (Kd) in nM range. The high selectivity of the MIP sensor against the interferences propachlor and metalaxyl has been confirmed. Finally, the reliability of MIP-GCE for ALA detection is proved in tap water samples spiked by ALA. These findings indicate that such a sensor can be used for in-field measurements of other herbicides as a simple detection platform.

Towards Phosphate Detection in Hydroponics Using Molecularly Imprinted Polymer Sensors.

An interdigitated electrode sensor was designed and microfabricated for measuring the changes in the capacitance of three phosphate selective molecularly imprinted polymer (MIP) formulations, in order to provide hydroponics users with a portable nutrient sensing tool. The MIPs investigated were synthesised using different combinations of the functional monomers methacrylic acid (MAA) and N-allylthiourea, against the template molecules diphenyl phosphate, triethyl phosphate, and trimethyl phosphate. A cross-interference study between phosphate, nitrate, and sulfate was carried out for the MIP materials using an inductance, capacitance, and resistance (LCR) meter. Capacitance measurements were taken by applying an alternating current (AC) with a potential difference of 1 V root mean square (RMS) at a frequency of 1 kHz. The cross-interference study demonstrated a strong binding preference to phosphate over the other nutrient salts tested for each formulation. The size of template molecule and length of the functional monomer side groups also determined that a short chain functional monomer in combination with a template containing large R-groups produced the optimal binding site conditions when synthesising a phosphate selective MIP.

Poly(3,6-diamino-9-ethylcarbazole) based molecularly imprinted polymer sensor for ultra-sensitive and selective detection of 17-β-estradiol in biological fluids

In this work, we reported the synthesis of 3, 6-diamino-9-ethylcarbazole and its application as a new monomer for preparation of molecularly imprinted polymer (MIP) electrochemical sensor. The as prepared MIP sensor exhibited ultrahigh sensitivity and selectivity for the detection of 17-β-estradiol in attomolar levels (1 × 10–18molL−1). The sensor works by detecting the change of the interfacial impedance that is derived from recognition of 17-β-estradiol on the MIP layer. The MIP sensor based on 3, 6-diamino-9-ethylcarbazole monomer revealed better performance than that of unmodified carbazole monomer. The monomer/template ratio, electropolymerization scanning cycles, and the incubation pH values were optimised in order to obtain the best detection efficiency. Under the optimised condition, the MIP sensor exhibits a wide linear range from 1aM to 10μM (1 × 10–18 ̶ 1 × 10−5molL−1). A low detection limit of 0.36aM (3.6 × 10–19molL−1) and a good selectivity towards structurally similar compounds were obtained. The proposed MIP sensor also exhibits long-term stability and applicability in human serum samples. These advantages enabled this MIP sensor to be a promising alternative of electrochemical sensor and may be extended to detection of other endogenous compounds.

Molecularly imprinted polymers for the selective detection of multi-analyte neurotransmitters

This paper reports on the development of electrochemical sensors for the detection of multiple neurotransmitters using molecularly imprinted polymers (MIPs). Pyrrole (PPy) and o-phenylenediamine (o-PD) were used as functional monomers for the MIP sensor development, and the characteristics of those sensors were analyzed. Specifically, we demonstrate a selective detection of dopamine (DA), norepinephrine (NE), and epinephrine (EP) by applying differential pulse voltammetry (DPV) to each uniquely developed MIP-based sensor. Furthermore, the selectivity of the analyte was quantified based on the sensitivity matrix. Our results demonstrate that all MIP sensors possessed higher sensitivity than non-imprinted (NIP) sensors due to the unique molecular receptors. The detection limits of the developed MIP sensors were less than 1.3×10−5M. The uniqueness of the cross-reactivity in the DA-imprinted and EP-imprinted sensors demonstrate the possibility of implementing a multi-analyte sensing platform that can detect multiple neurotransmitters simultaneously from a single sample solution.

Bioelectronic tongue using MIP sensors for the resolution of volatile phenolic compounds

Abstract The proposed approach reports the combined advantages of biosensors made of molecularly imprinted polymers (MIPs) and the modelling capabilities of Artificial Neural Networks (ANN) in a bio-electronic tongue (BioET) analysis system for the very first time. Molecularly imprinted polymers taylor-made for 4-ethylphenol (4-EP) and 4-ethylguaiacol (4-EG) and their control polymers, non-imprinted polymers (NIPs), were succesfully synthesized with similar morphologies and integrated onto an electrochemical sensor surface, as the recognition element, via sol-gel immobilization. The resulting MIP-functionalized electrodes were employed to arrange an array of different biosensor electrodes to quantify by means of ANN the binary mixtures of 4-EP and 4-EG yielding an obtained vs. expected correlation coefficient >0.98 and a normalized root mean square error (NRMSE)

Enhancing determination of quercetin in honey samples through electrochemical sensors based on highly porous polypyrrole coupled with nanohybrid modified GCE

A novel MIP/MIL-101 (Cr)/MoS2/GCE sensor was fabricated for the determination of quercetin (Qu), based on MIL-101 (Cr)/MoS2 modified GCE, followed by molecularly imprinted polymer (MIP) immobilized on modified electrode. Nanoscale materials of MIL-101 (Cr) and MoS2 as electrochemical sensor modifiers were synthesized via hydrothermal methods The physical characterizations of the prepared MIL-101 (Cr), MoS2 and MIL-101 (Cr)/MoS2 were examined by FTIR, XRD, BET and TEM. The influencing parameters controlling the performance of the prepared sensor were in detailed studied. Under the optimized conditions, the electrochemical behavior of Qu at the MIP/MIL-101 (Cr)/MoS2/GCE sensor was investigated by using differential pulse voltammetry (DPV) method. The proposed sensor possessed desirable linear relationship between the peak currents and the Qu concentrations. Two linear concentration ranges can be observed at the MIP/MIL-101 (Cr)/MoS2/GCE sensor in the ranges of 0.1 to 10.5μM and 10.5 to 700μM, with a detection limit of 0.06μM in phosphate buffer solution (PBS, pH=3.5) (S/N=3). Additionally, the MIP sensor presented excellent reproducibility, stability and selectivity. Furthermore, the imprinted sensor was also successfully applied for the determination of Qu in honey samples and received satisfactory recoveries.

Constructing a novel composite of molecularly imprinted polymer-coated AuNPs electrochemical sensor for the determination of 3-nitrotyrosine

A sensitive and highly selective imprinted sensor for detecting an oxidative stress biomarker 3-nitrotyrosine (3-NT) detection was developed based on electropolymerized pyrrole molecularly imprinted polymer (MIP) doped with gold nanoparticles (AuNPs) on a glassy carbon electrode (GCE) modified with activated multiwall carbon nanotube @ graphene oxide nanoribbons (AMWCNT@GONRs). Adding AuNPs into the polymer composite effectively generated electrical response by facilitating the charge transfer process. As the specific recognition sites, the fabricating imprinted polymer-AMWCNT@GONRs composite exhibited excellent sensitivity, stability and specific selectivity behavior towards 3-NT. The surfaces morphology of the MIP modified electrode was characterized by scanning electron microscopy (SEM) showing that AMWCNT@GONRs were well dispersed under the imprinted polymer owning to highly porous surface structure. Under optimal conditions, the determination range of imprinted sensor for 3-NT was linearly response from 0.2 to 50.0 μM with a detection limit (S/N = 3) of 50.0 nM. Furthermore, this modified MIP sensor was successfully used for detection of 3-NT in human serum and urine samples.

Electrochemical determination of enrofloxacin based on molecularly imprinted polymer via one-step electro-copolymerization of pyrrole and o-phenylenediamine

A novel molecularly imprinted polymer (MIP), poly(pyrrole-co-o-phenylenediamine) (p(Py-co-OPD)), has been developed in order to construct an enrofloxacin (EF) sensor by using cyclic voltammetry (CV) technique. The preparation conditions including the pH level, EF concentration, the number of CV cycles, extraction solution of the template and the incubation time were optimized. The performance of the MIP sensor was evaluated by square wave voltammetry (SWV). Under the optimal experimental conditions, the MIP sensor exhibited long time stability, good selectivity and a wide linear range of 1.0×10−4–1.0×10−10mol/L with a low detection limit of 6.57×10−13mol/L towards EF. Moreover, the sensor was successfully used to determine the EF amount in the pharmaceutical samples with satisfactory results.

Highly sensitive and selective sensor for sunset yellow based on molecularly imprinted polydopamine-coated multi-walled carbon nanotubes

Polydopamine (PDA) can be formed by monomeric self-polymerization in water. This convenient behavior was exploited to prepare a molecularly imprinted polymer (MIP) layer on the surface of multi-walled carbon nanotubes (MWCNTs) with sunset yellow (SY) as a template molecule. The prepared nanocomposites were characterized, and their electrochemical behavior towards SY was investigated. Under the optimized conditions, a glassy carbon electrode modified with the imprinted nanocomposite showed a highly selective and ultrasensitive electrochemical response to SY compared with the performance of control electrodes and previously reported electrochemical sensors for SY. The improved behavior of the developed sensor can be attributed to its superficial highly matched imprinted cavities on the excellent electrocatalytic matrix of MWCNTs and the electronic barrier of the non-imprinted PDA to outside molecules. The fabricated sensor expressed a linear relationship to SY concentrations from 2.2nM to 4.64μM with a detection limit of 1.4nM (S/N = 3). The sensor also exhibited excellent selectivity for SY over its structural analogs, good stability, and adequate reproducibility. The prepared sensor was successfully used to detect SY in real spiked samples. This methodology has potential application value and may be readily adapted to design other PDA-based MIP sensors.

Coupled electrochemical-chemical procedure used in construction of molecularly imprinted polymer-based electrode: a highly sensitive impedimetric melamine sensor

A novel molecularly imprinted sensor was fabricated and used for the impedimetric detection of melamine. Considering the identity of polymeric film and the pK a of a melamine template, an effective procedure was established to construct the MIP-based melamine sensor. The proposed method is based on the electropolymerization of pyrrole (Py) in the presence of melamine on the electrochemically reduced graphene oxide modified glassy carbon electrode (ERGO/GCE), followed by treatment with the solution of 1% H2O2 in alkaline water/CH3CN-mixed solvents. The surface morphology and the electrical feature of molecularly imprinted polymer (MIP) were characterized by scanning electron microscopy (SEM), Fourier transformation infrared spectroscopy (FTIR), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The EIS was also utilized to transduce the change of charge transfer resistance (R ct) at the interface of polymer film-electrolyte, after subsequent incubation of electrode in the solution containing different concentrations of analyte, and consequently, a linear response was obtained over the range of 4.0 to 240 nM with a detection limit of 0.83 nM (S/N = 3). The effect of possible interferences on the response of sensor was studied, and the results confirmed the good selectivity of the proposed device for melamine assay. The MIP sensor was successfully applied to determine melamine in a multiple concentration-spiked milk sample.

An electrochemical sensor based on a molecularly imprinted polymer for determination of anticancer drug Mitoxantrone

A novel electrochemical sensor based on the molecularly imprinted polymer (MIP) film is presented for the determination of an anticancer drug Mitoxantrone (MTX). The MIP film was prepared by electrochemical polymerization of β-cyclodextrins (β-CD) and MTX on a glassy carbon electrode (GCE) for the first time, wherein β-CD served as the functional monomer, MTX as the template that was extracted afterwards, thereby creating the imprinted cavities complementary to the template in the polymer matrix. MTX could be specifically recognized and binding by the imprinted cavities. The developed MIP sensor exhibits a rapid electrochemical response, high sensitivity and selectivity for the determination of MTX in pharmaceutical formulations and spiked urine samples. Moreover, the proposed approach presents distinct advantages over reported electrochemical methods for determination of MTX because it is a one-step preparation and the template molecule could be easily removed by cyclic voltammetry scans, and no elution reagent is required. Under the optimal experimental conditions, the linear response range for MTX concentrations by the MIP sensor was 6×10−8M–1×10−5M with a detection limit of 3×10−8M (S/N=3), showing a good sensitivity and low LOD for MTX detection. This study demonstrates that the proposed MIP sensor is feasible for the detection of anticancer drugs.

Electrochemical Quantitative Detection of Glial Fibrillary Acidic Protein Based on Molecularly Imprinted Polymer Sensor

Electrochemical Quantitative Detection of Glial Fibrillary Acidic Protein Based on Molecularly Imprinted Polymer Sensor