PVDF membrane immobilized acetylcholinesterase-based fluorescence biosensor for chlorpyrifos detection

Trace residues of chlorpyrifos (organophosphorus pesticides) pose significant environmental hazards due to their acute insecticidal toxicity. Chlorpyrifos inhibits acetylcholinesterase (AChE), which heightens the risks of neurological disorders. The implications of these interactions underscore the urgent need for detection strategies to mitigate the risks associated with chlorpyrifos exposure. Considering the inherently fragile nature of AChE, a novel composite membrane (PVDF/PDA/PEI) was introduced to immobilize AChE for its excellent simplicity, portability and ease of separation. And a ratiometric fluorescence biosensor based on photoluminescent carbon dots emitting at 468 nm and cobalt oxyhydroxide nanosheets emitting at 568 nm were constructed. The resulting fluorescence ratio at F468/F568 was served as a ratiometric fluorescence signal for AChE assay and chlorpyrifos detection, with a detection limit of 0.103 ng/mL. This study facilitates the precise monitoring of chlorpyrifos levels in real samples, providing a reliable method to detect even trace amounts of this widely used chlorpyrifos. By offering a balance between the activity and stability of fragile AChE, facilitating the utilization of PVDF/PDA/ PEI immobilized AChE in the fabrication of a ratiometric fluorescence sensor for the purpose of chlorpyrifos detection. This advancement not only improves detection sensitivity but also contributes significantly to environmental safety and public health monitoring.