Effects of the grafting on the fluorescence properties of CdTe nanocrystals

In this paper, we systematically investigated the influence of graft reagents having an amino or a carboxyl terminus with different chain lengths on the fluorescence properties of water-soluble thioglycolic acid-stabilized CdTe nanocrystals (TGA-CdTe). Strong enhancement effects of the grafting on the fluorescence intensity of TGA-CdTe were observed. The experiment results demonstrated that short-chain-length grafting can increase the fluorescence intensity of CdTe nanocrystals (NCs) better than long-chain-length grafting, and the grafting did not influence the emission wavelength of the CdTe NCs. The fluorescence intensity of the carboxyl-grafted TGA-CdTe was more stable than that of the amino-grafted TGA-CdTe at wide pH ranges (pH 5.1-10.0).