Disposable poly ( o -aminophenol)-carbon nanotubes modified screen print electrode-based enzyme sensor for electrochemical detection of marine toxin okadaic acid

Based on the inhibition of okadaic acid (OA) on protein phosphatase 2A (PP2A), we developed disposable poly- o -aminophenol-carbon nanotubes (PoAP-CNTs) modified screen print electrode (SPE)-based electrochemical enzyme sensor for OA detection. Electropolymerized PoAP-CNTs composite film was coated on electrode for the immobilization of PP2A. Owing to the excellent physicochemical characteristic of PoAP-CNTs film, the performance of enzyme sensor was enhanced. Under the optimal conditions, the biosensor provides a larger linear range, and lower detection limit for the analysis of OA compared with colorimetric PP2A inhibition assay and PP2A/SPE. The spiked OA shellfish samples were applied to verify the efficiency of method for OA detection. The results shows acceptable recovery rate and low RSD, demonstrating the applicability of this method for in suit OA assessment in the quality and toxicity monitoring of seafood.