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

Novel and effective coreaction accelerators are of great importance in electrochemiluminescence (ECL) systems. In this work, novel AuPt nanodonuts, i.e., SnS 2 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 SnS 2 QDs onto AuPt NR surfaces, which would promote the production of more coreactant intermediate in the SnS 2 QDs/K 2 S 2 O 8 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 SnS 2 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).