Enhanced Sensitivity for Aflatoxin B1 Detection in Food through a h-Zn1Cd5S-based Photoelectrochemical Aptasensor

Designing photoelectrochemical sensors for detecting ultra-trace amounts of Aflatoxin B1 (AFB1) in complex samples poses a significant challenge. In pursuit of this objective, we engineered hollow-structured ZnCdS (denoted as h-Zn1Cd5S) material and applied an electrodeposition method to introduce Au nanoparticles (AuNPs) on the surface. This approach resulted in a significant enhancement of the photocurrent response of the photoelectrode, attributed to the synergistic effects of the hollow structure and surface plasmon resonance, thereby underscoring its potential for advanced applications. Utilizing density functional theory, we computed the transfer route and energy band formation of photogenerated electrons. Subsequently, we developed an AFB1 photoelectrochemical (PEC) aptasensor based on the competition mechanism, coupled with aptamer probe technology. This aptasensor allows for the ultra-trace determination of AFB1, exhibiting a remarkable detection limit as low as 1.32 fg/mL and a linear range from 1.0×10-2 to 100.0 pg/mL. The PEC aptasensor for AFB1 demonstrates excellent sensitivity and selectivity. When applied to the detection of AFB1 in Tsaoko, wheat, and corn samples, its performance aligns closely with high-performance liquid chromatography (HPLC) results, validating its applicability for analyzing real-world samples.