Toxicity of CdTe QDs with different sizes targeted to HSA investigated by two electrochemical methods.

QDs have large scale application in many important areas with potential of unintentional exposure to the environment or organism during processing of a nanotechnology containing product's life cycle. In this paper, two classical electrochemical methods, cyclic voltammetry and electrochemical impedance spectroscopy were applied to investigate the influence of particle sizes of CdTe QDs on their toxicity targeted to human serum albumin (HSA) under simulative physiological conditions. The results show that the toxicity of yellow emitting QDs (YQDs) on HSA is slightly stronger than that of the green-emitting (GQDs) and red-emitting QDs (RQDs). We also compared these two classical electrochemical methods with the traditional fluorescence spectroscopy through the above results. The electrochemical methods may be more accurate and comprehensive to investigate the toxicity of QDs at the biomacromolecular level under certain conditions, though fluorescence spectroscopy is simpler and more sensitive.