Nanozyme activity of silver nanowires for colorimetric detection of bisphenol A following salting-out assisted liquid-liquid extraction

The increasing use of industrial chemicals has raised major concerns about their environmental and health impacts, with bisphenol A (BPA) being one of the most widely studied contaminants. In this work, we introduce a proof-of-concept approach that combines the peroxidase-like catalytic activity of silver nanowires (AgNWs) with a salting-out assisted liquid–liquid extraction (SALLE) strategy for BPA detection. AgNWs catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in an acidic environment, producing a measurable color change that is effectively suppressed in the presence of BPA. This inhibition enables a simple colorimetric quantification of BPA with a detection limit of 31.62 ng/mL (LOQ = 95.83 ng/mL). The method demonstrated a practical linear response within the range of 200–700 ng/mL, making it suitable for screening moderately contaminated water samples. Furthermore, the work offers good recovery values for the extraction of BPA from spiked environmental water samples. Integrating AgNWs nanoenzyme activity with an eco-friendly pre-concentration step provides a promising low-cost, straightforward, and rapid alternative to conventional chromatographic methods, particularly suited for preliminary screening of contaminated waters.