氯霉素分子印迹电化学传感器的制备与应用

Preparation and Application of a Chloramphenicol Electrochemical Sensor Based on Molecularly Imprinted Polymer

以纳米氧化铝(Al_(2)O_(3))和羟基化多壁碳纳米管(MWCNTs)为增敏材料,制备以氯霉素(CAP)为模板分子,间氨基苯酚(MAP)和β-环糊精(β-CD)为双功能单体的一种新型灵敏检测CAP的分子印迹电化学传感器。通过扫描电镜(SEM)、差分脉冲伏安法(DPV)和电化学交流阻抗法(EIS)对印迹传感器的表面形貌和电化学性能进行表征。同时优化了MWCNTs及Al_(2)O_(3)的修饰量、模板分子与功能单体的摩尔比、电聚合圈数、洗脱剂种类、洗脱时间、检测体系pH值和孵育时间等参数对印迹传感器响应的影响。结果表明,制备的传感器对CAP具有较高的选择性和灵敏度,归因于Al_(2)O_(3)和MWCNTs的协同作用能显著提高修饰电极的表面积和催化性能,以及使用双功能单体制备印迹膜具有较高的亲和力和选择性。在优化条件下,传感器的峰电流与CAP浓度在1.0~60.0 nmol/L范围内呈良好线性关系,检出限(3S/k)为0.14 nmol/L。将传感器用于自来水、饲料和牛奶样品中CAP含量的检测,加标回收率为88.0%~110%,相对标准偏差(RSD)小于10%。方法简单易行、准确可靠。

A novel molecularly imprinted electrochemical sensor sensitized with aluminium oxide(Al_(2)O_(3))and hydroxylated multi-walled carbon nanotubes(MWCNTs)was prepared for the sensitive determination of chloramphenicol(CAP)by using CAP as template molecule,m-aminophenol(MAP)andβ-cyclodextrin(β-CD)as binary functional monomers.The surface morphology and electrochemical performance of the imprinted sensor were characterized by scanning electron microscopy(SEM),differential pulse voltammetry(DPV)and electrochemical impedance spectroscopy(EIS).The experimental parameters influencing the response of the imprinted sensor,such as modification amount of MWCNTs and Al_(2)O_(3),molar ratio of template molecule to functional monomer,number of electropolymerization cycles,eluent type,elution time,pH value and incubation time were also optimized.Results showed that the prepared sensor exhibited high selectivity and sensitivity in the detection of CAP,which was attributed to the synergistic effect of Al_(2)O_(3) and MWCNTs to significantly enhance the surface area and catalytic performance of the modified electrode,as well as high affinity and selectivity of imprinted membrane prepared with the binary functional monomers.Under the optimal conditions,the peak current was linearly related to the CAP concentration in the range of 1.0-60.0 nmol/L,with a detection limit(3S/k)of 0.14 nmol/L.The sensor was applied to detect CAP in tap water,chicken feedstuff and milk samples,with recoveries of 88.0%-110% and relative stan dard deviations less than 10%.The proposed method is simple,accurate and reliable.