Signal-amplified electrochemiluminescence aptasensor for mucin 1 determination using CdS QDs/g-C₃N₄ and Au NPs@TEOA

A novel electrochemiluminescence (ECL) aptasensor, using graphite carbonitride (g-C₃N₄) capped CdS quantum dots (CdS QDs@g-C₃N₄) and Au nanoparticles decorated triethanolamine (AuNPs@TEOA) as dual coreactants, was proposed for the determination of mucin 1 (MUC1). Higher ECL efficiency was acquired due to the double enhancement contribution of CdS QDs and TEOA to Ru (bpy)₃²⁺ ECL. Additionally, AuNPs@TEOA also acted as nanocarrier for MUC1 aptamer immobilization. After the aptasensor was incubated in target MUC1, the decreased ECL emission was obtained because of the poor conductivity of MUC1. The ECL aptasensor displayed a good linear correlation for MUC1 in the range 0.1 pg mL^-1 -1000 ng mL^-1, and the detection limit was 33 fg mL^-1. MUC1 spiked into human serum samples was quantified to assess the practicability of the ECL aptasensor.