CdSe量子点荧光猝灭法测定尿嘧啶

Uracil Determination Based on Fluorescence Quenching of CdSe Quantum Dots

以CdSe量子点为荧光探针,基于荧光猝灭法对碱基尿嘧啶进行了定量检测,考察了缓冲液体系、反应时间、量子点浓度等多种因素的影响.实验结果表明,在pH7.4的0.2 mol/L Na2HPO4-NaH2PO4缓冲液中,反应时间为60 min,尿嘧啶浓度为10-6～10-4mol/L范围时,其线性回归方程为F0/F=0.992+3.35×104Q(mol/L),检测限为3.23×10-6mol/L(即0.36μg/ml).该方法检测范围宽,灵敏度高,为尿嘧啶的测定提供了新的方法.

Uracil （U） was quantitatively detected based on its fluorescence （FL） quenching of CdSe quantum dots （QDs）. The experimental conditions including buffer solution, concentration of CdSe QDs, and incubation time are optimized in view of their influence on the FL behavior of the QDs. Under the optimized conditions, i.e. Na2HPO4-NaH2PO4 buffer solution with pH 7.4 and 60 min of incubation, the emission intensity of CdSe QDs and the concentration of U follow the Stern-Volmer equation in the range of 10^-6 - 10^-4 mol/L. The obtained linear fitting equation is： Fo/F = 0.992 ＋ 3.35 × 10^4 Q （mol/L） with the correlation coefficient of 0.999 1. The method has a detection limit of 3.23× 10^-6 mol/L （0.36 μg/ml）. These results show that CdSe QDs can be potentially used as luminescent probe for detecting U.