β-Cyclodextrin protected Cu nanoclusters as a novel fluorescence sensor for graphene oxide in environmental water samples.

This paper proposed a simple and sensitive approach for detecting graphene oxide (GO) in a wide pH range in environmental water samples using fluorescent β-CD protected Cu NCs based on the hydrogen-bond interactions between GO and 6-SH-β-CD. The influences of dilution ratio and pH were investigated. We found that the fluorescence quenching efficiency of Cu NCs by GO remained almost the same under pH from 4 to 10, which benefitted the monitoring of GO under different pH conditions in real samples. The fluorescence quenching mechanism was also discussed. The fluorescence of β-CD protected Cu NCs could be quenched in the presence of GO with a lowest detection concentration of 0.1 mg·L-1 . Good linear correlations were obtained over the concentration range from 0 to 30 mg·L-1 at different pH values (pH = 4, pH = 7 and pH = 12). In addition, this method was successfully applied to the determination of GO in real samples which presents more opportunities for application in environmental and material sciences.