Enhanced detection of bisphenol A with silver-anchored N-doped carbon electrocatalyst

초록

To develop an efficient catalyst for bisphenol A (BPA) oxidation and detection, Ag nanoparticle (AgNP) decorated N-doped carbon (NC) composites were prepared by heat treatment of a polymer precursor synthesized through a microwave-assisted hydrothermal process, followed by nitric acid functionalization and subsequent AgNP decoration (Ag@NC). The morphology, chemical composition, and crystalline structure of the carbon composites were characterized using surface analytical methods, which confirmed the uniform dispersion of AgNPs on the N-doped carbon surface with enriched nitrogen functionalities obtained by nitric acid treatment. Electrochemical characterization revealed that Ag@NC exhibited enhanced conductivity, reduced charge-transfer resistance, and superior catalytic activity toward BPA oxidation compared to pristine and N-doped carbon. The sensor fabricated by coating Ag@NC with positively charged polyethylene imine (PEI) (Ag@NC/PEI) demonstrated a wide dynamic range (0.1-1000.0 mu M), a low detection limit of 6.3 nM, and excellent reproducibility (RSD <= 3.7%). The sensor also exhibited reliable stability, retaining similar to 94% of its response current after 30 days of storage. Furthermore, it was selectively detected in the certified reference material and extracted from a polycarbonate (PC) plastic bottle, confirming its practical applicability. These findings demonstrate that the Ag@NC composites are highly promising electrode materials for sensitive, reliable, and practical BPA detection.

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