Photoelectrochemical aptasensor based on cascade dual Z-scheme CdTe-polyaniline@MoS2 heterostructure for the sensitive carbendazim detection

Photoelectrochemical (PEC) aptasensing has been extensively studied for hazardous material (e.g., pesticide residue) detection, with investigation on photoactive materials being their main focus of study. Herein, a cascade Z-scheme [email protected] 2 ( [email protected] 2 ) heterostructure was designed to fabricate a PEC aptasensor for carbendazim (CBZ) detection in tomato. The [email protected] 2 heterostructure was prepared by taking advantage of electrostatic adsorption between components. The cascade Z-scheme electron transfer was verified in [email protected] 2 , resulting in a significantly enlarged photocurrent (e.g., 2.7-fold higher of that at CdTe/MoS 2 ) for the efficient separation of electron-hole pair. The PEC aptasensor was developed based on the principle that the specific binding of aptamer to target on the surface of [email protected] 2 increased the steric hindrance for electron transfer, facilitating a “signal-off” detection mode for CBZ. The fabricated aptasensor offered a linear range of 0.523–5230 nM (0.1–100 ng mL −1 ) with a detection limit of 1.74 × 10 -10 M (0.033 ng mL −1 ) for CBZ detection, and it was successfully applied to tomato sample analysis. This work will stimulate exploration of cascade Z-scheme materials for sensing, and provides a high-performance PEC sensing platform for the detection of various species.