Discrimination of copper and silver ions based on the label-free quantum dots

Abstract

A simple and fast method for copper ions (Cu2+) and silver ions (Ag+) detection was established with cadmium telluride quantum dots (CdTe QDs) as fluorescent probes. In the presence of Cu2+ or Ag+, the fluorescence intensity of TGA-CdTe QD can be significantly quenched, which fitted a linear relationship between the fluorescence quenching degree (F0–F)/F0 and the concentration of metal ions. In this work, the lowest detected concentration for Cu2+ and Ag+ was 35.0 nM and 25.3 nM, respectively. In addition, the differentiation of Cu2+ and Ag+ at different concentrations was realized with the principal component analysis (PCA). Furthermore, Cu2+ was successfully detected in body fluids. This method provides a good potential for copper ions and silver ions detection with simplicity, rapidity, and excellent selectivity.