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.     

基于金属卟啉的甲基磷酸二甲酯分子印迹聚合物微球的合成及性能

合成了分别以5-(4-甲基丙烯酰氧苯基)-10,15,20-三苯基锌卟啉(ZnMOTPP)和5-(4-甲基丙烯酰氧苯基)-10,15,20-三苯基钆卟啉(GdMOTPP)为功能单体, 甲基丙烯酸(MAA)为辅助功能单体的甲基磷酸二甲酯(DMMP)分子印迹聚合物微球. 扫描电子显微镜(SEM)表征结果表明, 微球平均粒径为50～100 μm, 粒度均匀. 与甲基丙烯酸作为功能单体的分子印迹聚合物微球的吸附性能和特异性进行对比发现, ZnMOTPP分子印迹微球的吸附性能优于 GdMOTPP分子印迹微球, 金属卟啉分子印迹微球的吸附性能优于仅以甲基丙烯酸作为功能单体的分子印迹微球, 并且微球对其印迹分子DMMP具有特异性吸附. Scatchard分析表明, DMMP分子印迹空穴中只存在一类结合位点, MIPMs-Zn+MAA的最大吸附量Q_max=148 μmol/g, MIPMs-Gd+MAA的Q_max=78.9 μmol/g, MIPMs-MAA的Q_max=13.57 μmol/g.     

磁性分子印迹电化学传感法检测痕量奥卡西平

该文以4-乙烯基吡啶和甲基丙烯酸酯为原料制备了一种可用于检测奥卡西平（OXC）的磁性分子印迹 电化学传感器（MNPs－MIP/MCPE）。首先,依据密度泛函数理论（DFT/B3LYP/6－31 + G）计算,实验成功地 筛选和构建出 OXC与功能单体的最佳组合及比例。随后,基于沉淀聚合法合成了能够识别 OXC的磁性分子 印迹膜（MNPs－MIP）,将MNPs－MIP覆于碳糊电极（MCPE）表面制成MNPs－MIP/MCPE。采用差分脉冲伏安 法（DPV）将 MNPs－MIP/MCPE 传感器用于不同浓度 OXC 的测定。结果显示,传感器的峰电流信号随 OXC 浓 度的增大而增大,且OXC分别在5 × 10－8 ～3 × 10－6 mol/L和3 × 10－6 ～1. 5 × 10－4 mol/L浓度范围内与其峰电流 信号呈线性关系,其线性方程分别为：Ip （μA）= 1. 755 + 1. 097c（μmol/L）,相关系数（r）= 0. 999 7 和 Ip （μA）= 0. 131 + 5. 177c（μmol/L）,r = 0. 999 6。OXC的检出限（LOD = 3S/m）为2. 06 × 10－8 mol/L。该传感器成 功用于实际样品中OXC含量的检测,其回收率为99. 4%~101%,相对标准偏差（RSD）为1. 5%～2. 5%。     

分子印迹电位型传感器快速检测猪尿液中的克伦特罗

以盐酸克伦特罗为模板分子,采用沉淀聚合法合成了克伦特罗的分子印迹聚合物,并以其为离子载体,制得分子印迹聚合物膜克伦特罗离子选择性电极。在最优实验条件下,电极对克伦特罗阳离子的检出限可达7.0×10-8mol/L,线性范围为1.0×10-7～1.0×10-4mol/L,能斯特斜率为55.7 mV/decade。此电极具有优越的选择性、快速的响应时间以及良好的稳定性;已成功应用于实际猪尿样品中克伦特罗的测定,加标回收率为98%～107%,检测时间小于3 min。     

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.     

Au-Pd合金纳米管修饰的尼古丁分子印迹膜传感器的研究

基于Au-Pd合金修饰的玻碳电极为工作电极,采用循环伏安法将邻氨基酚与尼古丁电沉积在工作电极上,制备了尼古丁分子印迹膜传感器。采用差分脉冲伏安法研究尼古丁在尼古丁分子印迹膜传感器上的电化学行为,考察了模板溶解时间、富集时间和溶液pH值对尼古丁测定的影响。在优化实验条件下,尼古丁分子印迹膜传感器的线性范围为1.2×10~(-7)~2.5×10~(-3) mol/L,检出限为4.6×10~(-8) mol/L。用该传感器对吸烟者血液中尼古丁的含量进行检测,结果表明,该传感器具有灵敏度高、线性范围宽、重现性及稳定性好等优点。     

分子印迹聚合物传感器的研究与发展

综述了分子印迹聚合物的历史发展、制备方法、聚合体系的选择、性能表征及作用机理。主要介绍了其作为传感器敏感膜方面的应用,并对需解决的问题提出了建议。     

盐酸阿霉素分子印迹传感器的制备及识别特性

采用自组装以及电聚合的方法,在磷酸盐缓冲液(PBS)中以3,4-乙烯二氧噻吩(EDOT)为功能单体,盐酸阿霉素(DOX)为模板,在金电极表面电聚合制备DOX印迹敏感膜(MIPs),构建了一种选择性检测DOX的分子印迹电化学传感器.采用循环伏安法(CV)及交流阻抗法(EIS)对其性能进行了表征.优化实验条件后,在含0.005 mol/L K3[Fe(CN)_6]及0.1 mol/L KCl的PBS中,应用差分脉冲伏安法(DPV)测试了该传感器的响应性能.实验结果表明,该传感器检测DOX的线性范围为4.0×10~(-7)~1.0×10~(-6)mol/L,相关系数为0.9967,检出限(S/N=3)达6.5×10~(-8)mol/L;采用电化学洗脱法可使传感器再生,对DOX的测定具有良好重现性及稳定性;该传感器对于干扰物长春碱、放线菌素D及5-氟尿嘧啶有微弱的电流响应,显示出良好的选择性.将该传感器用于人体血样中盐酸阿霉素的分析,回收率为96.0%~106.7%,表明其具有潜在的实用价值.     

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%。     

香豆素-3-羧酸分子印迹聚合物复合膜对底物的结合及渗透选择性质的研究

在光照和引发剂的作用下, 模板分子香豆素-3-羧酸、 功能单体丙烯酰胺和交联剂乙二醇二甲基丙烯酸酯(EDMA)或三甲氧基丙烷三甲基丙烯酸(TRIM)在聚偏氟乙烯(PVDF)微孔滤膜表面聚合形成分子印迹聚合物复合膜. 用高效液相色谱仪测定了分别以TRIM和EDMA为交联剂制备的分子印迹聚合物膜在不同溶剂中对混合底物的结合和渗透选择性. 结果表明, 以TRIM为交联剂的印迹膜对模板分子具有更高的结合和渗透选择性. 另外, 以乙腈或乙腈/水作为溶剂对分子印迹膜所作的实验和讨论有助于为从复杂样品中分离模板分子奠定理论和实验基础.     

多壁碳纳米管和分子印迹膜修饰电极检测猪尿液中莱克多巴胺

采用原位热聚合技术,分别以多壁碳纳米管(MWCNs)和分子印迹膜(MIM)修饰丝网印刷电极(SPE),与多壁碳纳米管和非分子印迹膜(NIM)修饰的丝网印刷电极组合在一起,并将其组合的丝网印刷电极通过电极插口与便携式电导仪相连接,组装成检测莱克多巴胺残留的电导型传感器,优化检测条件,并建立了检测莱克多巴胺的标准曲线,测试了实际猪尿样中莱克多巴胺的含量.通过扫描电镜分析了该分子印迹膜的表征结构.结果表明,在莱克多巴胺分子印迹膜表面形成了大量印迹微孔.本传感器装置检测莱克多巴胺具有很高的灵敏度和特异性,检出限为0.033 mg/L,线性范围为0.33～8.0 mg/L,基于猪尿样的检测回收率达到91％～98％,可实现现场快速检测.     

对羟基苯甲酸酯分子印迹电化学传感器的研制

利用分子印迹技术,以对羟基苯甲酸乙酯为模板分子,甲基丙烯酸为单体,在玻碳电极表面原位聚合分子印迹聚合物敏感膜.采用方波伏安法对对羟基苯甲酸乙酯在该印迹电极上的电化学行为进行了研究,当响应时间为15 min时,0.95 V(vs SCE)处的峰电流与对羟基苯甲酸乙酯的浓度在2.0×10-6 ～2.0×10-4 mol/L范围内呈线性关系,检出限(S/N=3)为1.0 μmol/L,而相同条件下,对羟基苯甲酸乙酯在控制电极上的响应非常小并对浓度变化不灵敏;同时在印迹电极上氧化峰电位较在裸电极上发生了微弱正移.同一支印迹电极对对羟基苯甲酸乙酯响应值的RSD为4.3%(n=10).该印迹电极对尼泊金酯类具有良好的选择性,对对羟基苯甲酸甲酯、丙酯以及丁酯的选择性系数分别为1.89、1.70和2.01;对结构相似的苯酚、对羟基苯甲酸、对氨基苯甲酸等响应不灵敏,对结构差异较大的如维生素C等几乎无响应.用该分子印迹电极对实际样品进行分析,加标回收率大于90%.     

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.     

Highly Selective Molecularly Imprinted Polymer Sensor for Indium Detection Based on Recognition of In‐Alizarin Complexes

A highly selective molecularly imprinted polymer electrochemical sensor for In³⁺ detection was proposed. In³⁺ ion was chelated with alizarin red S to form a complex In‐ARS. The complex was used as the template molecule to prepare a molecularly imprinted polymer (MIP) based sensor. The selectivity of the sensor was improved significantly due to the three‐dimensional specific structure of the complex, and the selective complexation of ligands for metal ions. Moreover, the sensitivity of the proposed sensor was improved by recording the reductive current of ligand in complex. This technique was highly sensitive for quantitative analysis of In³⁺ in the concentrations ranged from 1×10^?8 mol/L to 2.5×10^?7 mol/L with a detection limit of 4.7×10^?9 mol/L. The proposed sensor has been successfully used in detecting In³⁺ in real samples.     

以马来松香丙烯酸乙二醇酯为交联剂的咖啡因分子印迹电化学传感器

以咖啡因为模板分子, 含菲环骨架的马来松香丙烯酸乙二醇酯为交联剂, 甲基丙烯酸为功能单体, 在玻碳电极表面以自由基热聚合的方式制备分子印迹聚合物敏感膜, 构建了测定咖啡因的新型分子印迹膜电化学传感器. 通过循环伏安法、 差分脉冲伏安法及电化学交流阻抗法研究了传感器对咖啡因的响应特性. 结果表明, 在最佳的实验条件下, 传感器的峰电流与咖啡因浓度在3.00×10^-3~2.73 mmol/L范围内呈现良好的线性关系, 检出限(S/N=3)为1.12×10^-4 mmol/L. 传感器具有良好的选择性和重现性. 将该传感器用于可口可乐饮料中咖啡因含量的测定, 平均回收率为98.7%.     

Development and Characterization of an Electrochemical Sensor for Cinchonidine Detection Based on Molecularly Imprinted Polymer with Modified Rosin as Cross-linker

Molecularly imprinted polymers(MIPs) were applied as molecular recognition elements to an electrochemical sensor for cinchonidine(CD). A kind of MIP was synthesized with cinchonidine as template, modified rosin( ethylene glycol maleic rosinate acrylate) containing the skeleton of phenanthrene rings as cross-linker and methylacrylic acid as functional monomer. MIP membrane was prepared on a glassy carbon electrode for the determination of CD via free radical polymerization method. Electrochemical impedance spectroscopy(EIS) and cyclic voltammetry( CV) were used to characterize the membrane electrochemical behavior in electrode fabrication process. The experimental conditions were discussed. Under optimum conditions, it was found that the response of peak currents was linear to the concentration of CD in a range of 0.013―2.26 mmol/L. The detection limit for CD is 1 μmol/L, the relative standard deviation for 100 μmol/L CD is 1.34% and the incubation time is 2 min. The sensor was applied to the determination of CD in urine samples with satisfactory results.     

Highly Sensitive Molecularly Imprinted Sensor Based on Platinum Thin‐film Microelectrode for Detection of Chloramphenicol in Food Samples

A highly sensitive and selective electrochemical biomimetic sensor was fabricated for fast detection of chloramphenicol (CAP) in honey and milk samples. Platinum thin‐film microelectrode (Pt TFME), which could provide unique electrochemical properties and achieve measurement using very limited solution volumes, was surface‐modified by electropolymerizing o‐phenylenediamine. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize the preparation process of CAP‐imprinted poly(o‐phenylenediamine) film and rebinding ability of CAP into the imprinted cavities. The electrochemical properties of the sensor were further investigated with square wave voltammetry (SWV) by using K₃Fe(CN)₆ as an electroactive probe. The current difference of oxidation peaks of K₃Fe(CN)₆ had a good linear relationship with the concentration of CAP in the range of 0.9–10 nM. The detection limit was 0.39 nM based on the signal to noise ratio of 3. The developed sensor was successfully applied to determine CAP in honey and milk samples, and the result was in good agreement with that obtained by high performance liquid chromatography‐mass spectrometry (HPLC‐MS). The sensor showed high sensitivity and excellent selectivity to CAP in comparison to other structurally related and/or normally existing antibiotics, and demonstrated great promise for the rapid quantification of CAP in real food samples and field analysis.     

碳纳米管修饰电极分子印迹传感器快速测定沙丁胺醇

以单壁碳纳米管(SWNTs)为电极材料,应用分子印迹技术,以邻苯二胺为功能单体、沙丁胺醇为模板,采用电化学聚合法制备了一种新型的快速检测沙丁胺醇分子印迹传感器,并运用电化学方法去除模板.在磷酸盐缓冲溶液(PBS)中,利用线性溶出伏安法对印迹和非印迹膜的性能进行了比较,对分子印迹膜的影响因素进行了优化.实验表明,本传感器...     

Molecularly Imprinted Polymer Thin Film Based Surface Plasmon Resonance Sensor to Detect Hemoglobin

Molecularly imprinted polymer（MIP） films for hemoglobin detection were prepared onto the Au/Cr coated surface plasmon resonance（SPR） sensor chips by the in situ electropolymerization of 3-aminophenylboronic acid（3-APBA）.The formation of the films and rebinding processes of hemoglobin were monitored by in situ electrochemical-SPR（EC-SPR） spectroscopy,with allowed real-time observation of the simultaneous changes in electrochemical and optical properties of the films.Scanning electron microscopy（SEM） and atomic force microscopy（AFM）were used to characterize the surface morphologies of the MIP films.The effects of pH,ion strength,different metal ions on rebinding Hb,the specific binding and the selective recognition were investigated.The results obtained with the molecular imprinted SPR chips indicate a good adsorption of Hb in a range of 0.0005-5 mg/mL in 0.05 mol/L sodium phosphate buffer at pH=7.0.A linear calibration curve（R2=0.94） of the SPR sensor for Hb detection was obtained in a range of 0.05-5 mg/mL.The detection limit for hemoglobin by this method was 0.000435 mg/mL（S/N=3）.Interference studies indicate that the MIP films have a good selectivity compared with the referenced proteins.The stability of the sensor was also established.Results indicate that the SPR sensor chip keeps 87.6％ of its original response after 14 d of storage under dry and ambient conditions.     

基于分子印迹膜的检测牛奶中琥珀酸氯霉素残留传感方法的研究

采用光聚合法在一次性丝网印刷电极上制备琥珀酸氯霉素分子印迹膜,然后将丝网印刷电极通过电极插口与电化学分析装置相连接,组装成检测琥珀酸氯霉素残留的电化学传感仪.使用与传感装置相连接的记录仪记录响应的结果.采用本传感仪建立了检测氯霉素的标准曲线并测试了实际牛奶样品中氯霉素含量.电镜学观察表明,与非印迹膜相比,在印迹膜表面形成大量直径约为100 nm的印迹微孔.本传感仪装置检测琥珀酸氯霉素具有很高的灵敏度和特异性,检出限为2×10-9 mol/L,检测线性范围为1×10-8～1.2×10-5 mol/L,基于牛奶样品的检测回收率介于93.5%～95.5%之间.