Hydrothermal synthesis of GSH–TGA co-capped CdTe quantum dots and their application in labeling colorectal cancer cells

We have successfully synthesized GSH and TGA co-capped CdTe quantum dots (QDs) with good biological compatibility and high fluorescence intensity. The effects of different reaction time, temperature, pH value, ligand concentration and the molar ratio of GSH/TGA were carefully investigated to optimize the synthesis condition. The optical properties of as-prepared CdTe QDs were studied by UV–visible absorption spectrum and fluorescence spectrum, meanwhile their structure and morphology were characterized using transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR) and X-ray powder diffraction (XRD). Compared with the CdTe QDs that are single-capped with either GSH or TGA, the GSH–TGA co-capped CdTe QDs demonstrated significantly improved fluorescence intensity and optical stability. In addition, GSH–TGA co-capped CdTe QDs were conjugated to amonoclonal antibody ND-1. The GSH–TGA co-capped CdTe QDs-antibody probe was successfully used to label colorectal cancer cells, CCL187, in vitro.