AuPt Nanodonuts as a Novel Coreaction Accelerator and Luminophore for a Label-free Electrochemiluminescence Aptasensor.

ABSTRACT

Novel and effective coreaction accelerators are of great importance in electrochemiluminescence (ECL) systems. In this work, novel AuPt nanodonuts, i.e., SnS2 quantum dots (QDs)/Cys-AuPt heterogeneous nanorings (NRs), serve as both a highly effective coreaction accelerator and the luminophore in a label-free ECL aptasensor. The novel AuPt nanodonuts were formed by decorating SnS2 QDs onto AuPt NR surfaces, which would promote the production of more coreactant intermediate in the SnS2 QDs/K2S2O8 system. As a result, the ECL performance was greatly improved. Meanwhile, l-cysteine (l-Cys) played an important role in the combination between AuPt NRs and SnS2 QDs, and the nanodonuts served as the matrix to load numerous lincomycin (Lin) aptamers. Under optimal conditions, the ECL aptasensor exhibited ultrasensitive detection of Lin from 1 fg/mL to 0.1 pg/mL with a limit of detection (LOD) of 0.7 fg/mL (1.72 fM).