Molecularly Imprinted Electrochemical Sensors

In this review, the applications of molecularly imprinted polymer (MIP) materials in the area of electrochemical sensors have been explored. The designs of the MIPs containing different polymers, their preparation and their immobilization on the transducer surface have been discussed. Further, the employment of various transducers containing the MIPs based on different electrochemical techniques for determining analytes has been assessed. In addition, the general protocols for getting the electrochemical signal based on the binding ability of analyte with the MIPs have been given. The review ends with describing scope and limitations of the above electrochemical based MIP sensors.     

Molecularly Imprinted Poly-o-phenylenediamine Electrochemical Sensor for Entacapone

We have developed a molecularly imprinted polymer (MIP) electrochemical sensor for entacapone (ETC) based on an electropolymerised polyphenylenediamine (Po-PD) on a glassy carbon electrode (GCE) surface. The direct electropolymerisation of the o-phenylenediamine monomer (o-PD) was carried out with ETC as a template. The steps of electropolymerization process, template removal and binding of the analyte were tested by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) using [Fe(CN)₆]³⁻/[Fe(CN)₆]^{4 −} as a redox probe. The operation of the sensor has been investigated by differential pulse voltammetry (DPV). Under optimal experimental conditions, the response of the DPV was linearly proportional to the ETC concentration between 1.0×10⁻⁷ and 5.0×10⁻⁶ M ETC with a limit of detection (LOD) of 5.0×10⁻⁸ M. The developed sensor had excellent selectivity without detectable cross-reactivity for levodopa and carbidopa. The MIP sensor was successfully used to detect ETC in spiked human serum samples.     

Capacitive Chemical Sensor for Thiopental Assay Based on Electropolymerized Molecularly Imprinted Polymer

A novel capacitive sensor based on electropolymerized molecularly imprinted polymer (MIP) for thiopental detection is described. The molecularly imprinted film as a recognition element was prepared by electropolymerization of phenol on a gold electrode in the presence of thiopental (template). Cyclic voltammetry and capacitive measurements were used for characterization and evaluation of the polymeric film. The template molecules were removed from the modified electrode surface by washing with an ethanol:water solution. The sensor’s linear response range was between 3 and 20 µM, with a detection limit of 0.6 µM. The proposed sensor exhibited good selectivity, reproducibility. Satisfactory results were obtained in the direct detection of real samples.     

吲哚-3-乙酸分子印迹聚合物膜电化学传感器的研制

利用分子印迹技术,以吲哚-3-乙酸(IAA)为模板分子,甲基丙烯酸为单体,在玻碳电极表面采用原位聚合制备分子印迹敏感膜.采用方波伏安法对吲哚乙酸在该印迹电极上的电化学行为进行了研究.结果表明,0.62 V(vs.SCE)处的峰电流与吲哚乙酸的浓度在5.0×10-6～2.0×10-4mol/L范围内呈线性关系,检出限(S...     

分子印迹电化学传感器的研究进展

本文综述了分子印迹电化学传感器的制备及其在电分析化学领域中的应用研究。引用文献83篇。     

A Sensitive Electrochemical Sensor Based on Solution Polymerized Molecularly Imprinted Polymers for Procaine Detection

A sensitive and selective method for the determination of procaine hydrochloride using molecularly imprinted polymers (MIPs) modified glassy carbon electrodes was developed. The MIPs were prepared by solution polymerization using procaine hydrochloride as the template molecules and acrylic acid (AA) and vinyltriethoxysilane (WD‐20) as the functional monomer and cross‐linking agent, respectively. A film was formed on the surface of the glassy carbon electrodes and later cross‐linked with ethanol as solvent. Next, these electrodes were employed to detect procaine hydrochloride by differential pulse voltammetry (DPV). Under the optimized conditions, good linearity (correlation coefficient of 0.9986) was observed between the oxidation peak current and the concentration of procaine hydrochloride in the range of 4.0×10^?8 to 2.4×10^?5 M in a pH 7.0 0.04 M phosphate buffer solution, and the detection limit (S/N=3) was 1.02×10^?8 M. In addition, the stability and reproducibility of the sensors were satisfactory. Moreover, the concentration of procaine hydrochloride in human blood serum samples was detected, and its recoveries ranged from 97.5 % to 106.4 % with RSD less than 2.15 %. These results suggest that the prepared molecularly imprinted electrochemical sensors can be used for the determination of procaine in clinical studies.     

基于石墨烯的毒死蜱分子印迹电化学传感器的制备及对毒死蜱的测定

利用分子印迹技术,以马来松香丙烯酸乙二醇酯为交联剂,使用自由基热聚合法在石墨烯修饰的玻碳电极表面合成毒死蜱( CPF)分子印迹聚合膜,制得了CPF分子印迹电化学传感器。采用循环伏安法、线性扫描伏安法和电化学交流阻抗法等,考察了此CPF分子印迹膜的电化学性能。在最佳检测条件下,传感器的峰电流与CPF浓度在2.0×10-7~1.0×10-5mol/L范围内呈线性关系,线性方程为Ip(μA)=-7.1834-0.2424C (μmol/L),相关系数r2=0.9959,检出限为6.7×10-8 mol/L(S/N=3)。构建了CPF分子印迹电化学传感器的动力学吸附模型,测得印迹传感器的印迹因子β=2.59,结合速率常数k=12.2324 s。传感器表现出良好的重现性和稳定性,并成功用于实际水样和蔬菜样品中CPF的测定,加标回收率为94.1%~101.4%。     

Graphene Doped Molecularly Imprinted Electrochemical Sensor for Uric Acid

A highly sensitive uric acid molecularly imprinted electrochemical sensor was prepared by using graphene doped chitosan as the functional matrix and uric acid as the template molecule; a electrodeposition technique was used to form a controllable graphene–chitosan–uric acid composited film on glassy carbon electrode whose uric acid was removed via electrochemical induce elution. Under the optimized preparation and detection conditions, the detection sensitivity of uric acid at graphene doped molecularly imprinted sensor was improved significantly compared with the undoped molecularly imprinted sensor. The mechanisms of sensitivity enhancement were studied by a.c. electrochemical impedance, adsorption model, and chronocoulometry. The observations suggest the effect of sensitivity enhancement resulted from magnified surface area and good electronic conduction of graphene. Additionally, the developed sensor exhibited specific recognition to uric acid against the competitors which consisted of structure liked substances and coexisting interference in blood serum.     

基于石墨烯分子印迹电化学传感器测定芦丁

将石墨烯(GR)滴涂至裸Au电极表面,并以邻氨基酚为功能单体,芦丁为模板分子,制备了芦丁分子印迹膜电化学传感器,利用循环伏安法(CV)和差分脉冲伏安法(DPV)对制得的传感器进行了电化学性能研究,并且对制备条件和测定条件进行了优化。结果表明,与裸Au电极相比,该GR修饰的Au电极在[Fe(CN)_6]~(3-/4-)溶液中峰电流明显增大,显著提高了芦丁分子印迹传感器的灵敏度。在最优实验条件下,基于GR分子印迹电化学传感器在4.40×10~(-6)~2.80×10~(-4) mol/L范围内呈良好的线性关系,检测限为1.46×10~(-6) mol/L。用该传感器测定了黑茶中芦丁的含量,获得较好结果。     

自组装碳纳米管-氯洁霉素分子印迹溶胶-凝胶电化学传感器研究

结合自组装技术, 采用电聚合方法在碳纳米管修饰金电极表面制备对氯洁霉素具有特异性识别位点的分子印迹溶胶-凝胶薄膜, 成功构建了一种新型印迹溶胶-凝胶电化学传感器. 通过循环伏安法(CV)、示差脉冲法(DPV)、安培计时法(I-t)和扫描电镜(SEM)表征了该印迹溶胶-凝胶膜的电化学性能和表面形貌. 结果表明, 该传感器具有良好的选择性和灵敏度, 氯洁霉素在多壁碳纳米管修饰的印迹溶胶-凝胶传感器上的响应明显提高. 该印迹溶胶-凝胶传感器对氯洁霉素的浓度响应线性范围为5.0×10^-7~8.0×10^-5 mol/L, 检出限为2.44×10^-8 mol/L. 该传感器被成功地用于人体尿液中氯洁霉素的分析测定.     

Molecularly Imprinted Impedimetric Sensor for Determination of Mycotoxin Zearalenone

The mycotoxin zearalenone (ZEA) prompts reproductive toxicity due to its strong estrogenic effects. In this work, an electrochemical sensor for determination of ZEA was developed by electropolymerization of a molecularly imprinted poly (o‐phenylenediamine) (PPD) film on screen‐printed gold electrode (SPGE) surface. The sensor was examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) using K₃[Fe(CN)₆]/K₄[Fe(CN)₆] as redox probe. The molecularly imprinted polymer (MIP) sensor showed a wide determination range from 2.50 to 200.00 ngmL^?1 for ZEA. The Limit of detection (LOD) was calculated to be 0.20 ngmL^?1, based on the signal to noise (S/N) ratio equal to 3.0. The sensor displayed good repeatability, with RSD values≤4.6 %, and maintained 93.2 % of its initial response after storage for 10 days in air at room temperature. The developed method was successfully applied for the determination of ZEA in corn flakes with mean recoveries ranged from 96.2 % to 103.8 % and RSDs within the interval of 2.1 % to 3.8 %.     

异丙隆分子印迹敏感膜传感器

在弱酸(pH 5.5)条件下,采用电聚合法在金电极上制备邻氨基酚异丙隆分子印迹膜,对该印迹膜的性能、分子印迹效应和印迹膜对模板分子及其结构相似物的选择性响应等进行了研究.以K3Fe(CN)6为印迹电极和底液间的探针,建立了一种检测异丙隆的方法.该传感器对异丙隆具有良好的选择性和敏感度,异丙隆浓度在1.0×10-7～4.0×10-4 mol/L范围内与K3Fe(CN)6还原峰电流减少量呈线性关系; 检出限为2.95×10-8 mol/L.对农田水中异丙隆含量进行了测定,回收率为99.0%～102.0%.     

盐酸金霉素分子印迹电化学传感器的研制

构建了一种选择性检测盐酸金霉素(CTC)的分子印迹电化学传感器。在NaClO4溶液中,以邻氨基酚(OAP)为功能单体,盐酸金霉素(CTC)为模板,通过循环伏安法在玻碳电极表面上聚合制备了CTC印迹敏感膜(MIPs)。在含0.005 mol/L K3[Fe(CN)6]及0.1 mol/L KCl的磷酸盐缓冲液(PBS)中,应用差分脉冲伏安法(DPV)研究了传感器的响应性能。DPV峰电流差与CTC浓度在2.0×10!8~6.1×10!7mol/L范围内呈线性关系,检出限为1.5×10!8mol/L(3σ)。实验表明,用甲醇/H2SO4混合洗脱溶液可以使传感器再生,对CTC的测定具有良好的重现性,并具有良好的储存稳定性。传感器对于干扰物氯霉素及青霉素没有响应,结构相似的四环素、土霉素有微弱的响应,显示了良好的选择性。在牛奶和鸡肉实际样品中所测得的CTC加标回收率为86.4%~96.9%。与文献报道的CTC检测方法相比,本传感器具有低的检测限,操作简便,整个过程无需衍生化处理,响应快,成本低。     

盐酸普萘洛尔分子印迹电化学传感器的制备与研究

以盐酸普萘洛尔为目标模板分子,通过电聚合多巴胺,在多壁碳纳米管修饰的玻碳电极表面制备了对目标分子有特异响应的分子印迹电化学传感器.利用扫描电子显微镜、循环伏安法和差示脉冲伏安法对此传感器的表面形貌及性能进行了表征,并且优化了检测条件,研究了印迹传感器对模板分子及其结构类似物的选择性响应.结果表明:此传感器具有较好的选择性响应,而且碳纳米管的存在显著提高了传感器的灵敏度.盐酸普萘洛尔的浓度在0.20～100 μmol/L范围内与峰电流呈良好的线性关系;检出限为2.53×10-8 mol/L(S/N=3).此传感器还具有良好的稳定性和重现性.     

A Study of Preparation and Performance of a Dichlorvos Electrochemical Sensor Based on Molecularly Imprinted Technique

A new dichlorvos molecularly imprinted electrochemical sensor was prepared. The sensitive membrane sensor was fabricated by electro-polymerizing on an Au electrode surface using o-aminophenol as a monomer and dichlorvos as a template. The 5 mmol/L K₃[Fe(CN)₆] containing 0.1 mol/L KCl was used as the test background solution, while cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to study the properties of the senor. The changes of oxidation peak current versus dichlorvos concentration showed linearity in the range of 0.12–0.42 µmol/L (R ² = 0.9432) and 0.45–15 µmol/L (R ² = 0.9516) with a detection limit of 0.06 µmol/L (S/N = 3). Moreover, the selectivity and repeatability properties of the dichlorvos electrochemical sensor were examined. Results showed that the senor had excellent repeatability (RSD = 3.92%, n = 5), good selectivity to the dichlorvos in detection, and only a ten minute response time. Organophosphorus insecticides have some response signals in the detections.     

A Novel Electrochemical Sensor Based on Molecularly Imprinted Solid-Phase Extraction for Rapid Determination of Ractopamine in Pig Urine

A new absorbent (polymer) for solid-phase extraction of ractopamine (RAC) was synthesized on the multi-walled carbon nanotubes (MWCTs) using grafting technique and surface imprinting methods. The superficial characteristics of the polymer were studied by scanning electron microscopy (SEM) and UN spectrometry was applied to investigate the static and kinetic adsorption capacity of the new absorbent. After the experimental conditions for the solid-phase extraction of RAC were optimized, a sensing system for the determination of RAC was established by connecting the solid-phase extraction column with a portable amperometric sensing system. The SEM study showed that numbers of imprinted micro-pores were exhibited on the surface of the imprinted polymers, and the absorption experiments indicated that the molecularly imprinted absorbent possessed satisfactory kinetics for the adsorption of ractopamine. The current response of the amperometric sensor demonstrated a linear correlation to the concentration of RAC over the range of 50 to 450 nM (r = 0.998) and the detection limit was 15 nM. Satisfactory sensitivity and stability was also presented under the optimized experimental conditions. The recoveries of RAC samples reached 87.3–94.8% in urine sample.     

Electrochemical Sensor for trans‐Resveratrol Determination Based on Indium Tin Oxide Electrode Modified with Molecularly Imprinted Self‐Assembled Films

A voltammetric sensor for sensitive and specific determination of trans‐resveratrol (RES) were prepared based on immobilization of an RES‐imprinted film on the surface of functionalized Indium Tin Oxide (ITO) electrode, which was modified with γ‐methacyloxypropyl trimethoxysilane (γ‐MPS). Cyclic Voltammetry (CV) was presented to extract RES from the molecularly imprinted polymer film and RES were extracted rapidly and completely. The binding performance of the imprinted electrode with the template RES were investigated using differential pulse voltammetry (DPV). The results showed that the imprinted ITO film can give selective recognition to the template RES over that of structurally analogous molecules. A linear response to RES in the concentration range of 2.0×10^?6 M to 2.0×10^?5 M was observed with a correlation coefficient of 0.992, and the detection limit of the electrochemical sensor was 8.0×10^?7 M. Whereas, binding to the reference nonimprinted electrode, made in the same way but without the addition of template RES, there was almost no response to RES.     

氧化石墨烯基异丙隆分子印迹聚合物的制备及其吸附性能研究

以氧化石墨烯为载体,异丙隆为模板分子,采用表面印迹技术制备了分子印迹聚合物。采用透射电子显微镜、拉曼光谱和热重分析仪对该分子印迹聚合物的结构进行了表征,并通过动态平衡结合法研究了该分子印迹聚合物的吸附能力。结果表明:准二级动力学模型很好地拟合了吸附动力学,相关系数(R2)为0.999 7;与非分子印迹聚合物相比,制备的印迹材料表现出高吸附效率和快速的吸附动力学;选择性吸附试验表明该分子印迹聚合物对异丙隆具有选择性和特异性吸附。     

桑色素分子印迹传感器的制备与应用

以邻氨基酚( o-AP)为功能单体,桑色素为模板分子,基于分子间的相互作用力,在金电极表面电聚合制备具有特异性识别孔穴的桑色素分子印迹传感器膜。采用循环伏安法( CV)、差分脉冲伏安法( DPV)等研究了分子印迹膜的性能和分子印迹效应。探索了聚合膜配比及聚合扫描圈数对传感器性能的影响,优化了洗脱时间和印迹时间。比较了此传感器对其结构相似物的选择性响应,发现其对桑色素检测具有良好的选择性。在最佳实验条件下,此传感器对桑色素浓度定量测定范围为0.05~1.70μmol/L,线性方程为I(μA)=1.0800lgc(mol/L)+9.3599, R=0.9934,检出限为0.01μmol/L。用此传感器测定黑茶样品中桑色素的含量,加标回收率为104.0%~108.0%。     

Molecularly Imprinted Polypyrrole for DNA Determination

In this study graphite electrodes modified by a thin DNA‐imprinted polypyrrole layer, which was able to bind specific target‐DNA, are reported. For this aim, electrochemical synthesis of polypyrrole was performed on a pencil graphite electrode by cyclic voltammetry (CV) or by potential pulse sequences (PPS). The modified electrode surface was used for electrochemical determination of target‐DNA by differential pulse voltammetry. According to our best knowledge this is a first report on the application of DNA‐imprinted polymer for the determination of target‐DNA. The results showed that the molecularly imprinted polypyrrole (MIPPy) layer that formed on the carbon electrode surface was sensitive for target‐DNA, while the nonimprinted polypyrrole layer was not sensitive to the same target‐DNA. Comparison of electrodes modified using PPS and CV techniques is presented.