摘要
水相中合成了谷胱甘肽(GSH)修饰的CdTe量子点(GSH-CdTe QDs).利用紫外-可见吸收光谱(UV-vis)、共振瑞利散射(RRS)光谱、荧光光谱(FL)和傅里叶变换红外光谱(FTIR)研究了GSH-CdTe QDs与L-天冬氨酸(L-Aspartic acid,L-Asp)的相互作用机理.在pH为5.3的BR缓冲溶液中,GSH-CdTe QDs与L-Asp主要通过静电引力和氢键作用在GSH-CdTe QDs周围形成了粒径较大的聚集体,导致体系的RRS显著增强和GSH-CdTe QDs的荧光急剧猝灭.在一定浓度范围内RRS增强和荧光猝灭均与L-Asp的浓度成正比,其中RRS法灵敏度更高(对L-Asp检出限为14.2 ng?mL–1),据此建立了以GSH-CdTe QDs作RRS探针测定L-Asp的一种新方法.同时讨论了反应条件和共存物质对体系RRS强度的影响.用于实际尿样中L-Asp的测定,实验结果满意.
Glutathione（GSH） capped CdTe quantum dots（GSH-CdTe QDs） were synthesized in aqueous solution.The mechanism of interaction between GSH-CdTe QDs and L-Aspartic acid（L-Asp） was studied by UV-vis absorption,resonance Rayleigh scattering（RRS）,fluorescence and infrared spectra.In pH 5.3 BR buffer solution,L-Asp could be combined with the GSH-CdTe QDs by the electrostatic attraction and hydrogen bond,forming a bigger diameter aggregate,which resulted in RRS increased markedly and the fluorescence of GSH-CdTe QDs quenched sharply.The increased RRS intensity and the quenched fluorescence intensity were directly proportional to the concentration of L-Asp in a certain range and the sensitivity of RRS method was higher（the detection limit for L-Asp was 14.2 ngomL-1） than the fluorescence method,so a new sensitive RRS method for the determination of L-Asp was established by using GSH-CdTe QDs as a probe.In addition,the optimum conditions of the reaction and the influences of coexisting substances were tested by RRS method,which could be satisfactorily applied to the determination of L-Asp residues in urine samples.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2011年第24期2969-2974,共6页
Acta Chimica Sinica
基金
国家自然科学基金(No.20875078)
发光与实时分析重庆市重点实验室(西南大学)资助项目(No.CSTC
2006CA8006)
