Multi-spectroscopic techniques to evaluate the toxicity of alloyed CdSeS quantum dots

Alloyed CdSeS quantum dots (QDs) were successfully synthesized in aqueous phase using microwave irradiation. UV–vis spectroscopy, fluorescence spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques proved that the prepared alloyed QDs are composed of a CdSe-rich core and thick CdS shell with homogeneous size distributions. In order to study its biological toxicity, multi-spectroscopic techniques were adopted to investigate their conjugation with BSA. Fluorescence quenching methods indicated the prepared CdSeS QDs strongly quenched the fluorescence of BSA due to the formation of non-fluorescence ground-state complex. UV–vis absorbance spectra, synchronous fluorescence spectra and CD spectra further confirmed the alloyed CdSeS QDs binded with BSA and destroyed their hydrogen bonding networks, which induced the conformation changes of this macromolecule.