High-performance VS2 QDs-based type II heterostructured photoanode for ultrasensitive aptasensing of lysozyme

High visible-light active materials with boosted photoelectric conversion efficiency are the key to fabricate high-performance photoelectrochemical (PEC) sensor. Herein, we report in-situ formation of VS 2 QDs-Bi 2 S 3 heterostructure for promising application in constructing PEC aptasensor. Dramatically enhanced photoelectric conversion capacity is verified by photoluminescence spectroscopy (PL), electrochemical impedance spectroscopy (EIS) and PEC measurements. The intrinsic metallic feature of VS 2 , efficient visible light absorption of Bi 2 S 3 nanotube, and well-aliened band structure between them are responsible to substantially enhanced photocurrent. By covalently linking 5′-NH 2 -terminated lysozyme (Lys) aptamer on the VS 2 QDs-Bi 2 S 3 heterostructure, a self-powered PEC aptasensor for Lys is constructed. Under optimal conditions, ultrasensitive and selective detection of Lys is established in a wide linear range of 3.5 pM-70 nM with good selectivity and stability. The detection limit is 1.1 pM. Trace monitoring Lys in biological systems is realized with desired accuracy and satisfactory recovery. This work illustrates the prospect of VS 2 QDs-based heterostructure for PEC sensing and possible photocatalytic applications.