基于纳米金的分子印迹传感器检测果蔬中的氧化乐果和乐果

以甲基丙烯酸为功能单体,氧化乐果为印迹分子,构建了一种可用于检测果蔬中氧化乐果和乐果的分子印迹传感器.在金电极上电沉积金纳米粒子,然后将修饰电极浸入10 mL含有氧化乐果和甲基丙烯酸的聚合物溶液中进行9次循环电聚合(-0.3～0.3 V),无水甲醇/乙酸洗涤除去模板分子.循环伏安法和电化学阻抗谱表征传感器,差分脉冲伏安...     

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.     

微囊藻毒素分子印迹传感器的制备与应用

以邻氨基酚为单体,微囊藻毒素(MC-LR)为模板,采用循环伏安法在金电极的表面电聚合成膜分子印迹材料,制备了传感器。采用安培法对MC-LR进行检测。在制备影响条件最佳值(pH=4.5;单体/模板=1.4×108∶1;洗脱时间10 min)的基础上,对该传感器的线性范围、使用寿命、选择性等进行了研究,并与液相色谱方法进行对比,结果表明:该传感器对MC-LR具有良好的选择性和灵敏度,线性范围为0.05～0.35 mg/L;加标回收率为80%～105%;检出限为7.3μg/L。与液相色谱方法对比,当置信度为99%时,无系统误差。     

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.     

3D石墨烯修饰的猛杀威分子印迹电化学传感器的制备

以猛杀威为模板分子、丙烯酰胺( AM)为功能单体、马来松香丙烯酸乙二醇酯( EGMRA)为交联剂、自制的3D石墨烯(3D-rGO)为增敏材料,在玻碳电极表面合成分子印迹聚合物,制备检测猛杀威的分子印迹电化学传感器。运用扫描电镜(SEM)对自制3D石墨烯的形貌进行了表征,通过循环伏安法(CV)、差分脉冲伏安法(DPV)和交流阻抗法(EIS)对猛杀威传感器的性能进行了研究。结果表明,猛杀威的浓度在8.0×10-8~8.0×10-6 mol/L范围内与响应电流值呈良好的线性关系,线性相关系数R=0.9954,检出限为7.3×10-8 mol/L (S/N=3),猛杀威分子印迹敏感膜的印迹因子β=3.88,且相对于3种结构类似物的选择因子α垌1,说明此传感器具有良好的选择性。将此传感器应用于生菜样品检测,加标回收率在96.7%~98.7%之间。     

L-色氨酸分子印迹传感器敏感膜的制备与性能

以L-色氨酸(L-Trp)为模板分子, 邻苯二胺(o-PD)为功能单体, 在金电极表面原位合成了分子印迹聚合物敏感膜; 通过循环伏安法(CV)、 差示脉冲伏安法(DPV)和电化学阻抗谱法(EIS)考察了该电极的性能. DPV测试结果表明, 在1×10^-8~2×10^-7 mol/L范围内, 峰电流与L-Trp的浓度呈线性关系, 检出限为0.3×10^-8 mol/L; 选择识别性实验结果表明, L-Trp印迹敏感膜的印迹因子达到3.72, 相对于干扰物的选择因子均大于1, 对与L-Trp结构相似的L-酪氨酸(L-Tyr)的选择因子也达到2.30, 说明该印迹膜对L-Trp具有良好的选择性; 识别过程动力学研究结果表明, 印迹膜对L-Trp的识别是一个两步连续发生的过程, 即快结合过程和慢吸附过程.     

磁性石墨烯修饰辛基酚印迹传感器制备及应用研究

以辛基酚(4-OP)为模板分子,多巴胺为功能单体,采用电聚合技术在磁性石墨烯修饰碳电极表面制备对辛基酚具有高选择性与灵敏性的印迹电化学传感器。采用循环伏安法(CV)和差分脉冲伏安法(DPV)对此印迹传感器的电化学性能进行详细表征;采用扫描电子显微技术对修饰电极的形貌进行表征。结果表明,此印迹电化学传感器对辛基酚具有良好的特异识别性能。采用 DPV 法考察了孵化时间和洗脱溶剂对印迹传感器性能影响,结果表明,最佳孵化时间为14 min。此印迹电化学传感器的响应电流(△IR )与辛基酚在5.0×10-6~5.0×10-9 mol/ L 范围内浓度的负对数(-lgC)呈良好的线性关系,线性方程为△IR ( mA)=-0.25lgC(mol/ L)+2.35,检出限为3.64×10-10 mol/ L (S/ N=3)。此印迹电化学传感器对辛基酚具有良好的选择性和灵敏性,成功用于实际水样中辛基酚的检测,回收率为96.0%~104.0%。     

氯霉素分子印迹复合膜的制备及电化学

采用电化学聚合法合成了对氯霉素（CAP）有快速响应和高灵敏度的聚苯胺/聚吡咯分子印迹复合膜修饰电极。 通过微分脉冲伏安法、扫描电子显微镜对制备的分子印迹复合膜的电化学性质及表面形貌进行了表征。 结果表明,以铁氰化钾为电化学探针,该膜对CAP的测定电化学信号响应快速、灵敏度高、选择性和膜再生性能良好。 对CAP检测的线性范围为5.00×10-8～1.05×10-6 mol/L,检测限为2.09×10-9 mol/L。     

分子印迹聚合物修饰电化学晶体管检测抗坏血酸分子

以抗坏血酸(AA)为模板分子、邻苯二胺(o-PD)为功能单体,在金电极表面电聚合制备分子印迹聚合物膜(MIP),并以该MIP修饰的电极为栅极制备了具有高选择性、高灵敏度的AA电化学晶体管(OECT)传感器件。应用循环伏安法(CV)、交流阻抗法(EIS)对分子印迹聚合物电极进行一系列的表征与检测。实验结果表明:以pH=5.2,浓度为0.2mol/L HAc-NaAc(体积比2.1∶7.9)的缓冲液为背景溶液,o-PD与AA的物质的量之比为1∶2,以0.5V/s的扫描速率在0~0.8V内扫描20圈,所得分子印迹膜电极性能最佳。应用以该分子印迹修饰电极作为栅极的电化学晶体管检测AA,得到AA浓度的检测限为0.3μmol/L,沟道电流与AA浓度在0.3~3μmol/L(低浓度)与3~100μmol/L(高浓度)这2个范围内成线性关系。     

A novel sensor of cysteine self-assembled monolayers over gold nanoparticles for the selective determination of epinephrine in presence of sodium dodecyl sulfate

A novel sensor of cysteine self-assembled monolayers over gold nanoparticles modified gold electrode has been constructed for the determination of epinephrine in presence of sodium dodecyl sulfate (Au/Au(nano)-CysSDS). Electrochemical investigation and characterization of the modified electrode are achieved using cyclic voltammetry, linear sweep voltammetry, and scanning electron microscopy. The Au/Au(nano)-CysSDS electrode current signal is remarkably stable via repeated cycles and long term stability, due to the strong Au-S bond, compared to the Au/Au(nano) electrode. The catalytic oxidation peak currents obtained from linear sweep voltammetry (LSV) increased linearly with increasing epinephrine concentrations in the range of 2 to 30 μmol L(-1) and 35 to 200 μmol L(-1) with correlation coefficients of 0.9981 and 0.9999 and a limit of detection of 0.294 nmol L(-1) and 1.49 nmol L(-1), respectively. The results showed that Au/Au(nano)-CysSDS can selectively determine epinephrine in the coexistence of a large amount of uric acid and glucose. In addition, a highly selective and simultaneous determination of tertiary mixture of ascorbic acid, epinephrine, and acetaminophen is explored at this modified electrode. Excellent recovery results were obtained for determination of epinephrine in spiked urine samples at the modified electrode. Au/Au(nano)-CysSDS can be used as a sensor with excellent reproducibility, sensitivity, and long term stability.     

Molecularly Imprinted Polyresorcinol Based Capacitive Sensor for Sulphanilamide Detection

A molecularly imprinted polymer (MIP) based capacitive sensor for antibiotic detection in drinking water and milk has been developed on a gold coated silicon electrode (Au Electrode). The electrode was fabricated by electropolymerizing monomer resorcinol (RN) on Au surface in presence of sulphanilamide (SN) as a template molecule, to get insulated RN polymer antibiotic composite. The insulation of the polymer film was improved by incubation of electrode in 1‐Dodecanethiol solution. Subsequently MIP sensor was obtained by extraction of SN in ethanol and acetic acid solution. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) measurements were performed for characterization of the developed MIP electrode at different steps of fabrication. The surface morphology of MIP electrode was characterized using atomic force microscopy (AFM), X‐ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive x‐ray spectroscopy (EDS). Performance of MIP sensor was evaluated by measuring change in capacitance against varying concentration of SN using EIS. A linear response in the range 1 to 200 μg L^?1 SN was recorded for MIP sensor with a detection limit of 0.1 μg L^?1. The developed MIP sensor exhibited good selectivity towards SN in water and milk with recoveries in the range 92 % to 105 %. The obtained results suggest the usability of MIP based sensor for SN estimation in water and milk samples.     

基于抗原决定基的胰岛素分子印迹电化学传感器

采用抗原决定基法制备了胰岛素电化学分子印迹传感器.以胰岛素C端多肽作为模板分子,定向自组装在Au电极上,以邻苯二胺为功能单体,电化学聚合制备分子印迹聚合膜.以NaOH为洗脱液,洗脱模板分子,形成的与胰岛素C端多肽三维结构相匹配的分子印迹孔穴能特异性识别胰岛素.重吸附胰岛素分子后,以K3[Fe(CN)6]/K4[Fe(CN)6]为探针,通过测量探针在电极表面产生的电流大小实现胰岛素的间接测定.在1.0 × 10-14~5.0 × 10-13 mol/L浓度范围内,传感器的电流响应值与胰岛素浓度呈良好的线性关系,检出限为7.24 × 10-15 mol/L(3σ).此传感器具有较好的选择性和稳定性,并成功用于血清样品中胰岛素的测定.     

基于分子印迹电聚合膜的褪黑素传感器的研究

在弱酸条件下,以邻苯二胺为功能单体,褪黑素为模板,以电化学聚合物法在铂电极表面合成了性能稳定的褪黑素分子印迹聚合物膜.采用循环伏安法(CV)和差分脉冲法(DPV)对分子印迹传感器的识别性能进行了研究.结果表明:此传感器对褪黑素具有快的响应、良好的选择性和高的灵敏度.以K3Fe(CN)6为电子传递媒介,建立了一种差分脉冲伏安法(DPV)间接检测褪黑素的分析方法.在1×10-10～1×10-8 moL/L范围内,褪黑素的浓度与K3Fe(CN)6的相对峰电流变化呈良好的线性关系;检出限为1×10-11 mol/L(S/N=3).将此传感器应用于复合褪黑素及尿样中褪黑素含量的测定,加标平均回收率大于94％.     

Preparation of Molecularly Imprinted Electrochemical Sensor for Detection of Vincristine Based on Reduced Graphene Oxide/Gold Nanoparticle Composite Film

An innovative molecularly imprinted electrochemical sensor was fabricated based on reduced graphene oxide (RGO) and gold nanocomposite (Au) for rapid detection of vincristine (VCR). The RGO‐Au composite membrane was obtained via direct one‐step electrodeposition technique of graphene oxide (GO) and chloroauric acid (HAuCl₄) on the surface of a glassy carbon electrode (GCE) by means of cyclic voltammetry (CV) in the potential range between ?1.5 and 0.6 V in phosphate buffer solution (PBS) of pH 9.18, which is capable of effectively utilizing its superior electrical conductivity, larger specific surface area due to its synergistic effect between RGO and Au. The molecularly imprinted polymers (MIPs) were synthesized on the RGO‐Au modified glassy carbon electrode surface with VCR as the template molecular, methyl acrylic acid (MAA) as the functional monomer, and ethylene glycol maleic rosinate acrylate (EGMRA) as a cross‐linker. The performance of the sensor was investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) in detail. Under the optimum conditions, the fabricated sensor exhibited a linear relationship between oxidation peak current and VCR concentration over the range of 5.0×10^?8–5.0×10^?6 mol·L ^minus;1 with a correlation coefficient of 0.9952 and a detection limit (S/N=3) of 2.6×10^minus;8 mol·L^minus;1. The results indicated that the imprinted polymer films exhibited an excellent selectivity for VCR. The imprinted sensor was successfully used to determine VCR in real samples with recoveries of 90% –120% by using the standard addition method.     

分子印迹电化学传感器检测水杨酸

以水杨酸(SA)为模板分子,邻苯二胺(o-PPD)及吡咯(Py)为复合功能单体,在石墨烯修饰的玻碳电极表面制备分子印迹电化学传感器(MIP/GO/GCE),用扫描电镜(SEM)观察印迹膜的表面形貌,方波伏安法(SWV)和循环伏安法(CV)对分子印迹传感器的性能进行表征。通过优化实验条件,显示SA浓度在1.0×10-8~1.0×10-2 mol/L范围内,分子印迹传感器峰电流与SA浓度负对数具有良好的线性关系,检出限为8.6×10-9 mol/L。该传感器对SA具有良好的选择性,样品回收率为101%~106%,相对标准偏差(RSD)为3.8%。SA分子印迹传感器的制备简单、抗干扰性好、灵敏度高、成本低廉,具有较好实用价值。     

聚苯胺分子印迹膜电化学传感器检测氯霉素

以苯胺为功能单体和交联剂,氯霉素(chloramphenicol,CAP)为模板分子,采用电化学聚合法(循环伏安法)在金电极上合成了对CAP具有快速响应能力的聚苯胺分子印迹膜;结合差示脉冲伏安法建立了针对氯霉素的检测方法,并将所制备的聚苯胺分子印迹膜用作电化学传感器以测定氯霉素眼药水中的氯霉素.结果表明,所制备的聚苯胺分子印迹膜具有制备简单、响应快速、灵敏度高、再生性能良好等特点;其对氯霉素眼药水中的氯霉素的检测结果令人满意,有望用于实际样品中氯霉素的检测.     

Construction of a novel electrochemical sensor based on molecularly imprinted polymers for the selective determination of chlorpyrifos in real samples

We present a novel electrochemical sensor based on an electrode modified with molecularly imprinted polymers for the detection of chlorpyrifos. The modified electrode was constructed by the synthesis of molecularly imprinted polymers by a precipitation method then coated on a glassy carbon electrode. The surface morphology of the modified electrode was characterized by using field‐emission scanning electron microscopy and transmission electron microscopy. The performance of the imprinted sensor was thoroughly investigated by using cyclic voltammetry and differential pulse voltammetry. The imprinted electrochemical sensor displayed high repeatability, stability, and selectivity towards the template molecules. Under the optimal experimental conditions, the peak current response of the imprinted electrochemical sensor was linearly related to the concentration of chlorpyrifos over the range 1 × 10⁻¹⁰–1 × 10⁻⁵ mol/L with a limit of detection of 4.08 × 10⁻⁹ mol/L (signal‐to‐noise ratio = 3). Furthermore, the proposed molecularly imprinted electrochemical sensor was applied to the determination of chlorpyrifos in the complicated matrixes of real samples with satisfactory results. Therefore, the molecularly imprinted polymers based electrochemical sensor might provide a highly selective, rapid, and cost‐effective method for chlorpyrifos determination and related analysis.     

分子印迹膜电化学传感器检测土壤中莠去津

本文报道了一种对莠去津有识别特性的分子印迹膜的制备,即在含和不含模板分子(莠去津)的情况下,通过循环伏安技术在金电极表面沉积2-巯基苯并咪唑,制备了2-巯基苯并咪唑聚合膜.利用循环伏安法对印迹和非印迹膜行为进行了评价,对分子印迹膜的影响因素进行了筛选和优化.实验表明,该分子印迹膜对莠去津具有良好的选择性和灵敏度.莠去津的还原峰电流与莠去津的浓度在 1.2 ×10 - 8mal/L～8.0 ×10 - 5mol/ L 范围内具有良好的线性关系( r=0.99862),检出限可达 3.0 ×10 - 9mol/ L.将此传感器用于土壤中莠去津的测定,回收率在90.8% ～ 98.2%之间,取得了很好的结果.     

Enantioselective sensor based on microgravimetric quartz crystal microbalance with molecularly imprinted polymer film

We report a novel quartz crystal microbalance sensor that provides enantioselectivity to dansylphenylalanine enantiomers by using a molecularly imprinted polymer film as a recognition element. The polymeric recognition thin film, imprinted with chiral dansyl-L-phenylalanine, was immobilised on a gold electrode modified with a photoactive precursor monolayer via a self-assembly process using photopolymerization. The fabricated sensor was able to discriminate between L- and D-dansylphenylalanine enantiomers in solution owing to the enantioselectivity of the imprinted sites. The enantiomeric composition of L- and D-enantiomeric mixtures could be quantitatively determined by the fabricated sensor. The detection limit is 5 micrograms mL-1 with a response range of 5-500 micrograms mL-1 at pH 10.0. The influence of the template concentration on the sensitivity and selectivity of the synthesised polymer membranes was investigated and optimised. The surface characteristics of the polymer coating were studied by varying the pH value of the buffer solution, and a convenient regeneration process was proposed to increase the reproducibility and reusability of the sensor by flushing with pH 2.0 buffer. The selectivity and recognition mechanism of the imprinted polymer film were studied with compounds that are structurally related to the template. The method presented in this work provides a novel means of preparing highly selective and sensitive chemical sensors via self-assembly and molecularly imprinting techniques.