A novel aptamer-based photoelectrochemical sensor for zearalenone detection: Integration of g-C3N4/BiOBr with in situ growth Ag2S quantum dots

Abstract

Zearalenone (ZEN), a secondary metabolite mycotoxin primarily synthesized by Fusarium species and prevalent in cereal grains, exerts estrogenic effects that could induce reproductive toxicity and teratogenic outcomes. To enhance the precision of ZEN detection, we have developed an innovative photoelectrochemical (PEC) aptamer-based sensor employing in situ growth silver sulfide (Ag₂S) quantum dots-sensitized graphitic carbon nitride/bismuth oxybromide (g-C₃N₄/BiOBr) heterojunction. The g-C₃N₄/BiOBr composite exhibits robust structural stability and straightforward synthesis. In situ growth Ag₂S quantum dots could significantly amplify the signal, thereby elevating the sensor’s sensitivity. The sensor utilizes ZEN-specific aptamers for target-specific binding, ensuring high selectivity. Within the concentration range of 0.001 to 100 ng·mL⁻¹, the photocurrent response demonstrated a significant linear correlation with the logarithmic scale of ZEN concentration, with a detection limit reaching 0.122 pg·mL⁻¹. This PEC aptamer sensor exhibits excellent stability, reproducibility, and selectivity, which is expected to be used as an effective analytical tool for ZEN detection in practical applications.