Manganese modified CdTe/CdS quantum dots as a highly selective probe to detect trace copper element in beer samples

Abstract

This paper describes the investigation of manganese modified CdTe/CdS quantum dots as a fluorescence probe for trace copper detection. Manganese modified CdTe/CdS quantum dots were prepared in aqueous solution and were characterized by ultraviolet-visible absorbance, fluorescence spectra, transmission electron microscopy and X-ray diffraction. The as-synthesized manganese modified CdTe/CdS QDs presented a high photoluminescence quantum yield of 84%. The functionalized nanoparticles were used as a fluorescence probe for Cu²⁺. The interference study demonstrated that the normal foreign ions, such as Na⁺, Mg²⁺, Al³⁺et al., had very low interference for the detection of Cu²⁺, and the calibration plot of F⁰/F versus concentration of Cu²⁺ was linear in the range of 5.0 × 10⁻⁹ to 5.0 × 10⁻⁷ mol L⁻¹ with a correlation coefficient of 0.9991. The ultrasensitive fluorescence probe built was directly applied to the detection of trace copper element in beer samples with satisfactory results.