关键词: 电化学发光, 适体, 可卡因, 点击化学, 重氮盐法

Abstract: 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.

Key words: electrogenerated chemiluminescence, aptasensor, cocaine, click chemistry, diazotization