Highly sensitive and selective fluorescent assay for quantitative detection of divalent copper ion in environmental water samples

摘要

It was found that Cu2+ has a great catalytic effect on p-cresol oxidation by hydrogen peroxide under alkaline conditions, leading to an intense fluorescence signal due to the fast formation of 2,2′-dihydroxy-5,5′-dimethylbiphenyl, an oxidation product of p-cresol. Investigation of the fluorescence spectra of the p-cresol–hydrogen peroxide system demonstrated the catalytic behavior of Cu2+. On this basis, a very simple, sensitive, and selective fluorescent method was established for the determination of trace copper in this study. Under the optimal conditions, the proposed system could respond down to 1.0 × 10?8 mol L?1 of Cu2+ with a linear calibration range of 3.0 × 10?7 mol L?1 to 5.0 × 10?5 mol L?1. The relative standard deviation (RSD) was 2.1% for 7.0 × 10?6 mol L?1Cu2+ (n = 15). The proposed method was successfully applied in the determination of trace Cu2+ in lake, river and swimming pool water samples with satisfactory results. The results obtained by the proposed method are in good agreement with those obtained by a conventional atomic absorption spectroscopy method...