基于电化学双共价键法构建可再生高灵敏的电化学发光适体传感器检测可卡因

基于点击化学和重氮盐法的双共价键固定化方法，制备了一种高灵敏、可重复使用的电化学发光(ECL)适体传感器. 该方法以可卡因为分析物，以可卡因适体为分子识别物质，以钌联吡啶衍生物为ECL信号物质. 采用电化学方法在玻碳电极表面重氮化叠氮苯胺，通过点击反应连接炔基功能化的钌联吡啶衍生物标记可卡因适体，获得适体传感器. 该传感器在共反应剂存在下，产生弱的电化学发光信号，可卡因存在下，电化学发光信号增加. 基于此，建立了“信号增强”型检测可卡因的电化学发光分析新方法. 电化学发光信号与可卡因浓度在0.1 nmol·L^-1 ~ 100 nmol·L^-1范围内呈良好的线性关系，检出限为60 pmol·L^-1. 该传感器具有良好的稳定性，可重复多次使用. 该双共价键法在构建ECL传感器方面具有很好的应用前景.

Sensitive and Reusable Electrogenerated Chemiluminescence Aptasensor Fabricated by Electrochemically Double Covalent Coupling Method for the Detection of Cocaine

A double covalent coupling method based on click chemistry and diazonium chemistry was developed for the fabrication of a sensitive and reusable electrogenerated chemiluminescence (ECL) aptasensor. As a proof-of-concept, cocaine was chosen as a model target, and a specific aptamer was chosen as a recognition molecule element, while ruthenium complex derivative (Ru1) as an ECL signal compound. The ECL aptasensor was fabricated by electrochemically diazotizing a phenylazide on the surface of a glassy carbon electrode, and then, coupling the alkyne functionalized Ru1-labeled cocaine aptamer through click chemistry. The ECL aptasensor was facilely used to determine cocaine in the range from 0.1 nmol·L^-1 to 100 nmol·L^-1 with the detection limit as low as 60 pmol·L^-1 within 30 min via “signal on” mode. The advantage of the ECL aptasensor was further exemplified by good stability and reusability. This work demonstrates that the double covalent coupling method is a promising approach for the fabrication of the ECL biosensor.