基于银纳米粒子-CdTe量子点复合物荧光探针检测水样和血清中L-半胱氨酸

Determination of L-Cysteine in Water and Serum Based on Silver Nanoparticles-CdTe Quantum Dot Complex Probe

利用无荧光的碳量子点-银纳米颗粒(CQDs-AgNPs)中Ag+与CdTe QDs表面S 2-的强亲和作用,通过S-Ag键形成弱荧光的CQDs-AgNPs/CdTe QDs纳米复合物探针。L-半胱氨酸(L-Cys)中-S-与复合物探针中Ag+竞争络合,可使CdTe QDs的荧光恢复,基于L-Cys对复合物探针的荧光恢复作用,建立了水样和血清中L-Cys的荧光检测新方法。最佳条件下,该方法的检出限和相对标准偏差分别为32 nmol/L和2.6%。方法具有灵敏度高、操作简单的优点,已成功应用于水样和人血清中L-Cys的测定。

The weakly fluorescent CQDs-AgNPs/CdTe QDs nanocomposite probes has been formed by S-Ag bonds because of the strong affinity of Ag+in non-fluorescent carbon quantum dot silver nano particles composite(CQDs-AgNPs)with S 2-on the surface of CdTe QDs.Due to the competitive complexation of-S-in L-cysteine(L-Cys)with Ag+in the complex probe,the fluorescence of CdTe-QDs was activated.Based on the fluorescence activating effect of L-Cys on CQDs-AgNPs/CdTe QDs,a new fluorescence detection method for L-Cys in water and serum was established.Under the optimal conditions,the detection limit and RSD of this method were 32 nmol/L and 2.6%.It has the advantages of high sensitivity and simple operation and has been successfully applied to the determination of L-Cys in water and human serum with satisfactory results.