A rapid and simple strategy for discrimination and detection of catechol and hydroquinone by fluorescent silicon nanoparticles

In this work, fluorescent silicon nanoparticles (Si NPs) with good water solubility were facilely synthesized by one-step hydrothermal method. The obtained bright blue emitting Si NPs were employed as a fluorescent probe for simultaneously discriminating and sensitively quantifying two dihydroxybenzene (DHB) isomers (catechol (CC) and hydroquinone (HQ). Specifically, the fluorescence of Si NPs was dramatically quenched by HQ without a fluorescence shift. Interestingly, Si NPs revealed an obvious ratiometric fluorescent response characteristic toward CC, and an obvious fluorescent color change from bright blue to green was easily detected. Based on these, a simultaneous visual discrimination strategy for HQ and CC was proposed, and the determination of the concentration of HQ and CC with high sensitivity was obtained, respectively. The proposed strategy was also successfully applied to the assay of HQ and CC in real water samples. Moreover, the fabrication of luminescent test strip based on Si NPs and its application for straightforward visual discrimination of HQ and CC may open new applications of Si NPs in environmental chemistry.