Metallic Bi-decorated BiVO4 nanosheets enabling improved photoelectrochemical detection of trace chlorpyrifos under visible light through localized surface plasmon resonance.

A visible-light-powered photoelectrochemical (PEC) sensor was devised for chlorpyrifos (CPs) determination  using metallic Bi-decorated BiVO4 nanosheets (Bi@BiVO4 NSs) with localized surface plasmon resonance (SPR) synthesized via a one-step hydrothermal method. It was observed that Bi@BiVO4-based PEC sensors exhibit significantly enhanced PEC responses over pristine BiVO4 due to the collaborative effect of metallic Bi's SPR phenomenon and BiVO4's visible-light-driven properties. Furthermore, the addition of CPs selectively suppresses the photocurrent signal of the sensor due to the in-situ formation of Bi-CPs complexes, which hindered electron transfer through specific chelation reactions between Bi sites and CPs. The designed PEC sensor achieved high-sensitivity detection of CPs, with a linear concentration range from 0.02 to 20 ppb and a detection limit of  0.01 ppb. These attributes  may offer a blueprint for developing diverse PEC sensing systems to monitor various environmental pesticide contaminants like CPs by synergistic integration of visible-light-responsive BiVO4 and SPR-active metallic Bi.