In-situ HF-etched MXene as a novel electrode modifier for sensitive detection of bisphenol A

This study explores the use of MXene, a relatively recent class of 2D materials, as an innovative modifier of glassy carbon (GC) electrodes for the electrochemical detection of bisphenol A (BPA), a compound of significant environmental and health concern. MXene Ti₃C₂ was synthesized via in-situ hydrofluoric acid generation using a NaF/HCl mixture that is considered a milder synthetic route in comparison with ex-situ hydrofluoric acid, and safer because it avoids the handling and storage of commercial HF. Nanomaterials obtained at various stages of MXene synthesis were morphologically characterized using scanning electron microscopy. With respect to the bare GC, MXene improved the BPA electroanalysis due to the known MXene properties such as metallic conductivity. This enhanced response was further improved when MXene was exfoliated via a delamination process. Scan rate studies proved that the BPA mechanism was governed by a diffusion-controlled process. Once MXene concentration in aqueous suspensions used to modify the GC surface was optimized, pH and differential pulse parameters were adjusted. The optimal conditions were 0.1 M phosphate buffer at pH 7 as electrolyte, pulse amplitude of 60 mV and scan rate of 20 mV/s. Sensor performance evaluation yielded a detection limit of 0.11 μM. The applicability of the sensor was supported by the analysis of real water samples. Results were corroborated by ultra-high performance liquid chromatographic analysis, demonstrating the sensor's applicability and reliability.