莱克多巴胺核酸适配体电化学生物传感器的研制

莱克多巴胺(RAC)被大量非法用于畜牧生产,易在动物组织残留,对人体造成危害。因此,研发灵敏、快捷的检测RAC的新方法是有效控制RAC滥用的关键环节之一。通过等温滴定量热法筛选到了一条对莱克多巴胺有高亲和力(Kd=1.66×10-6mol/L)的核酸适配体,利用该适配体作为识别分子成功的构建了莱克多巴胺适配体电化学生物传感器。差分脉冲伏安法分析,在0.5~1.0×102ng/ml浓度范围内,峰电流值的差值ΔIp与莱克多巴胺浓度的对数呈现良好的线性关系,相关系数R2=0.977 0,检测限达到0.1 ng/ml,反应时间为15 min。对同一浓度的莱克多巴胺重复检测7次,其峰电流值的RSD值为3.8%;说明该传感电极具有良好的检测重现性。不仅如此,该适配体传感器还具有良好的选择性。

Development of An Electrochemical Aptasensor Basic on the ssDNA Aptamer of Ractopamine

Ractopamine was illegally used in stock farming widely. The ractopamine residues in animal tissues had a potential risk to human beings. Therefore, a sensitive and selective analytical method was developed for determination and monitoring of ractopamine. In this paper, a single-stranded DNA aptamer which could bind actopamine with high affinity was obtained by Isothermal Titration Calorimetry method. With this aptamer as a bio-recognizer, an electrochemical biosensor of detecting ractopamine was developed successfully. According to the differential pulse voltammetry analysis, a linear relationship was observed between the peak current value (ΔIp) and the log concentration of ractopamine ranging from 0.5 ng/ml to 1.0×10² ng/ml, and the correlation coefficient was 0.977 0. The detection limit was 0.1 ng/ml with a reaction time of 15 min. Ractopamine with a same concentration was detected 7 times and the RSD was 3.8%, it indicates the aptasensor have a good reproducibility. What' more, the aptasensor have a good specificity to RAC.