基于CdSe-CdTe量子点能量转移荧光猝灭法测定前列腺抗原

研究了CdSe-CdTe量子点间发生的荧光共振能量转移,并用于荧光猝灭法测定超痕量前列腺抗原(PSA)。在pH 8.0的Tris-HCl缓冲溶液中,CdSe-CdTe间发生有效能量转移,使CdTe荧光大大增强。PSA抗原与CdTe标记的PSA抗体发生特异性反应,使能量转移体系的CdTe上的荧光强度降低,即发生猝灭。建立了CdSe-CdTe能量转移荧光猝灭法测定PSA抗原的方法。在优化的实验条件下,PSA抗原的线性范围为0.28～10μg/L,相关系数r=0.9992,检出限达1.5×10-2μg/L(n=11)。

Fluorescence Resonance Energy Transfer Between Quantum Dots of CdSe and CdTe and Its Application for Determination of Serum Prostate Specific Antigen

Fluorescence resonance energy transfer(FRET) from CdSe quantum dots to CdTe quantum dots and the application for determining serum prostate specific antigen(PSA) were studied.It was found that the effective energy transfer can occur between CdSe and CdTe in the Tris-HCl buffer solution at pH=8.0 in which the CdTe fluorescence intensity has been increased.As adding prostate specific antigen,the fluorescence intensity of CdSe-CdTe system is decreasing and finally quenching because of the specific immunological reaction between the PSA antigen and CdTe labled PSA antibody.There were good linear correlations between the concentrations of PSA antigen and the fluorescence quenched intensities.Then a new determination strategy of PSA was built by using the CdSe-CdTe system.Under optimum conditions,the linear range of determining PSA antigen was 0.28-10 μg/L,with a correlation coefficient of r=0.9992 and a detection limit of 1.5×10-2 μg/L(n=11).