用巯基乙酸(TGA)、半胱氨酸(L-Cys)和谷胱甘肽(GSH)这三种巯基稳定剂在水相中制备了CdTe量子点(QDs).红外光谱(FTIR)分析结果表明,三种稳定剂都成功地利用Cd2+与巯基之间的配位与QDs相结合并起到保护及稳定的作用.利用荧光光谱对不同QDs的荧光性能进行了研究,结果表明当采用GSH作为稳定剂时,QDs的生长速率较快,且最大发射波长能够达到约680nm;L-Cys-CdTe的生长速率次之,也能生成具有较大发射波长的QDs;TGA-CdTe的生长速率最慢,且最大发射波长只能达到约620nm,但是其荧光强度较高,适于制备对荧光强度要求较高的QDs.通过MTT(噻唑蓝)比色法对细胞存活率进行测定,同时利用显微镜对细胞形貌进行观察,结果表明各量子点都具有一定的细胞毒性,但TGA-QDs对细胞的伤害作用更大,以20μg/mL的浓度对细胞培养24h后,细胞存活率只有52.6%.
CdTe quantum dots(QDs) were prepared in aqueous phase using thioglycolic acid(TGA),L-cysteine(L-Cys),and glutathione(GSH) as stabilizing agents.The luminescent properties of CdTe QDs with different stabilizing agents were studied by using fluorescence spectra.FTIR spectra analysis demonstrates that CdTe QDs are capped with stabilizing agents through the coordination interaction between Cd2+ and S.Fluorescence spectra show that CdTe QDs with longer emission wavelength(680nm) can be synthesized more easily when L-Cys or GSH is chosen as stabilizing agents and TGA is proper to prepare highly luminescent QDs because of the effect between Cd2+ and sulfhydryl group.The MTT assay and morphology analysis of U87MG cells suggest that the QDs with different stabilizing agents are all toxic to cells.The cytotoxicity of TGA-QDs is higher than that of L-Cys-and GSH-CdTe.The cell viability is only 52.6% when U87MG cells are treated with 20μg/mL of TGA-QDs for 24h.