In-situ growth of SnO2 nanoparticles on Nb2CTx nanosheets as highly sensitive electrochemical sensing platform for organophosphorus pesticide detection

In this study, the SnO 2 /Nb 2 CT x MXene nanocomposite containing 0D/2D interfaces was prepared by situ growth strategy of one-step hydrothermal method . A SnO 2 /Nb 2 CT x MXene based acetylcholinesterase (AChE) biosensor was constructed for pesticide detection. Highly conductive Nb 2 CT x MXene, acting as substrate material, restrained the agglomeration of nanoparticles (NPs) and accelerated electron migration due to the confinement effect and well-known accordion-like layered structure. In addition, SnO 2 anchored on both sides of the Nb 2 CT x MXene nanosheets effectively provided a large surface area, abundant surface groups and active sites, which preserved numbers of electrons at the interface of the heterojunction . The SnO 2 /Nb 2 CT x MXene hybrids with outstanding conductivity, good biocompatibility and structural stability were beneficial for AChE immobilization. Under the optimized conditions, as-fabricated electrochemical biosensor demonstrated superior performance with linear detection range of 5.1 × 10 −14 - 5.1 × 10 −7 M for chlorpyrifos , along with the limit of detection (LOD) down to 5.1 × 10 −14 M (calculated for 10% inhibition). Furthermore, it is highly expected that this biosensor can be applied for the detection of other organophosphorus pesticides in the environment, providing an effective nanoplatform in biosensing field.