CuInS2 Quantum Dots-based Off/On Probe for Detection of Cetyltrimethylammonium Bromide and L-Cysteine

Abstract

We developed a convenient method for cetyltrimethylammonium bromide (CTABr) detection based on the quenching phenomenon of CuInS2 quantum dots. There existed a good linear relationship between the fluorescence intensity of CuInS2 quantum dots and CTABr concentration from 0.08μmol/L to 6μmol/L with a detection limit of 25nmol/L. The quenched fluorescence intensity of CuInS2 quantum dots by CTABr could be recovered by L-cysteine, which could be also used to detect L-cysteine from 0.05 to 100μmol/L with a detection limit of 20nmol/L.