Highly sensitive electrochemiluminescence aptasensor based on a g-C3N4-COOH/ZnSe nanocomposite for kanamycin detection.

Schematic showing the steps involved in fabrication of the electrochemiluminescence aptasensor. [Display omitted] • A novel and highly sensitive ECL aptasensor was constructed for kanamycin detection. • g-C 3 N 4 -COOH/ZnSe was used for constructing ECL aptasensor and promote the ECL intensity. • The proposed ECL aptasensor presented splendid sensitivity, specificity and stability. In this paper, carboxylated C 3 N 4 (g-C 3 N 4 -COOH) was prepared by a new method, and then combined with ZnSe quantum dots (QDs) through amide reaction to form g-C 3 N 4 -COOH/ZnSe nanocomposite and used for detecting kanamycin. The prepared g-C 3 N 4 -COOH/ZnSe nanocomposite was used as the subatrate of aptasensor. Then, the g-C 3 N 4 -COOH/ZnSe nanocomposite-modified electrode was incubated with aptamer DNA (NH 2 -DNA), after cholamine blocked the unbond sites of the electrode surface, the ferrocene-labled quenching probe (Fc-DNA) as electrochemiluminescence (ECL) signal quencher was incubated on the electrode surface through base complementation with aptamer DNA. In the absence of kanamycin, the ECL signal was quenched effectively by Fc-DNA. On the contrary, kanamycin was specifically bond with aptamer DNA, and Fc-DNA was detached from the aptasensor electrode surface because of the deformation of aptamer DNA, generating an effectively enhanced ECL signal. The aptasensor exhibited a wide detection range for detecting kanamycin (1.0 nM − 100 μM) with a low limit of detection (0.7982 nM). The prepared aptasensor displayed a stable and selective detection for kanamycin, and also provided a promising strategy for a variety of other protein target. [ABSTRACT FROM AUTHOR]