Nanomolecularly imprinted polymer–surface plasmon resonance platform for monitoring trace-level Bisphenol A in drinking water

Abstract

Abstract Bisphenol A is a widespread endocrine-disrupting contaminant frequently detected in aquatic environments, creating a need for rapid and reliable methods for water quality monitoring. Here we show that a solid-phase-synthesized nanomolecularly imprinted polymer (nanoMIP) can be integrated into a surface plasmon resonance (SPR) platform for selective, label-free detection of bisphenol A in water. The nanoMIPs exhibited uniform spherical morphology with an average hydrodynamic diameter of 94 nm, enabling homogeneous immobilization on gold SPR chips. Real-time measurements showed concentration-dependent binding over the 5–800 nM range with a detection limit of 1.46 nM. The sensor exhibited heterogeneous binding behavior, strong discrimination against structurally related bisphenols, and high imprinting efficiency compared with control nanoMIPs. Validation against liquid chromatography–mass spectrometry yielded recoveries of 96.90–98.93%. Analysis of commercial carboy waters revealed detectable bisphenol A and temperature-dependent migration. These findings demonstrate that the nanoMIP–SPR platform provides a rapid, reusable, and amplification-free strategy for sensitive monitoring of bisphenol A in aqueous environments.