Sandwich-type photoelectrochemical aptasensor based on Cu₂MoS₄/CdS/In₂S₃ nanoclusters for highly sensitive detection of zearalenone in foods

In this study, a sandwich-type photoelectrochemical (PEC) aptasensor based on Cu₂MoS₄/CdS/In₂S₃ nanoclusters was resoundingly exploited for the detection of zearalenone (ZEN) in foods. Specifically, indium tin oxide (ITO) coated glass slides were decorated with Cu₂MoS₄/CdS/In₂S₃ and then ZEN aptamer-1 to create photoactive substrates (Cu₂MoS₄/CdS/In₂S₃-Apt1), with MoS₂ quantum dots modified with ZEN aptamer-2 (MoS₂ QDs-Apt2) serving as a PEC signal quencher. In the presence of ZEN, the close proximity of MoS₂ QDs-Apt2 to Cu₂MoS₄/CdS/In₂S₃-Apt1 created competition for light absorption and electron donors, resulting in a decrease in photocurrent but boosted detection sensitivity. The aptasensor that was constructed demonstrated a broad linear range (10^-5-10³ ng/mL) with a limit of detection (LOD) as low as 2.38 fg/mL. In addition, the aptasensor offered excellent stability, anti-interference properties, and practicality for ZEN detection in real food samples. This work offers a new approach for the ultrasensitive detection of harmful mycotoxins in foods.