“Turn-on” fluorometric probe for hydroquinone and catechol based on an in situ reaction between protamine sulfate and dihydroxybenzene isomers and the formation of fluorescent polymer nanoparticles

Abstract

Hydroquinone (HQ) and catechol (CC) pose serious risks to human and ecosystem health, so it is important to develop sensitive methods for detecting HQ and CC. Here, we describe an environmentally friendly turn-on fluorescent method for detecting HQ and CC involving monitoring the intrinsic fluorescence of fluorescent polymer nanoparticles (FPNs) synthesized by crosslinking protamine sulfate with HQ or CC in an aqueous solution. The FPN fluorescence intensities at excitation/emission peaks of 333/430 and 320/397 nm were related to the HQ and CC concentrations, respectively. A linear relationship was found between the fluorescence intensity and HQ or CC concentration. The detection limits for HQ and CC were 0.21 and 0.33 μM, respectively. Importantly, no interferences from 10 common interfering substances were found, meaning that the method is very selective. The method was successfully used to detect HQ and CC in spiked water samples and gave satisfactory results.