Pt@COOH-MWCNT enhanced conductive hydrogel with antibacterial and salt-tolerant properties for sensitive electrochemical detection of bisphenol a in seawater

Pt@COOH-MWCNT/PVA/AM hydrogel is synthesized by in situ gelation method. • Hydrogel modified electrode is used to sensitive electrochemical analysis of BPA. • Good properties of conductivity, antibacterial and salt-resistant are realized. • The sensor has a wide range of 0.05–1000.00 μM and a low LOD of 0.045 μM. Bisphenol A (BPA), which is extensively employed in plastics and food-contact products, poses serious hazards to the ecological environment and human health because of its endocrine disruptor property. Owing to its wide usage and environmental persistence, sensitive, selective and rapid BPA detection is urgently required, particularly in seawater. In this work, a conductive hydrogel prepared by anchoring Pt nanoparticles (NPs) onto carboxyl-functionalized multi-walled carbon nanotubes (COOH-MWCNT) was used to modify a glassy carbon electrode (GCE) for BPA electrochemical detection. The morphology and structure of the resulting composite were characterized, which revealed a dense, three-dimensional porous conductive network with fast electron transport ability and good mechanical stability. The incorporation of Pt@COOH-MWCNT significantly improved both the electrical conductivity and the electrocatalytic oxidation performance toward BPA. The fabrication and electrochemical detection parameters were optimized. Under optimal conditions (0.1 M phosphate buffer solution, pH 6.0), the sensor exhibits a BPA linear response range of 0.05–1000.00 μM with a detection limit of 0.045 μM, along with superior anti-interference, good stability, reproducibility (RSD = 0.9%), excellent salt tolerance, and antibacterial activity. When applied to real seawater samples, the recoveries were ranged from 97.50% to 106.00% with a relative standard deviation below 3.5%, confirming the sensor's favorable accuracy and reliability. The proposed sensor integrates robust structural integrity, enhanced conductivity, high catalytic activity, cost-effectiveness, and antibacterial performance, which offers a new strategy for on-site rapid monitoring of BPA in seawater environments with great application potential. The detection of bisphenol A (BPA) in seawater remains challenging due to complex matrices and the lack of simple, low-cost sensing platforms, as conventional electrochemical sensors often involve tedious fabrication or suffer from limited performance. Herein, a Pt@COOH-MWCNT/PVA/AM conductive hydrogel is fabricated via a straightforward in situ gelation strategy, providing a facile and cost-effective approach. Exploiting the high conductivity of COOH-MWCNT, the electrocatalytic activity of Pt nanoparticles, and the porosity, antibacterial property, and salt tolerance of the PVA/AM matrix, the constructed sensor achieves sensitive BPA detection over a wide linear range (0.05–1000 μM) with a low detection limit (0.045 μM), along with good reproducibility, anti-interference capability, and stability. Satisfactory recoveries (97.50%–106.00%) obtained in real seawater samples confirm its analytical reliability. This work offers a promising strategy for developing robust, low-cost electrochemical sensors suitable for on-site monitoring of BPA in complex marine environments. Download: Download high-res image (144KB) Download: Download full-size image