硫量子点的光稳定性研究

Photostability of Sulfur Quantum Dots

以聚乙二醇-400为钝化剂,以过氧化氢辅助刻蚀的自上而下法合成了分散性良好、荧光性质稳定的硫量子点(SQDs),采用氙灯照射的方式系统研究了硫量子点在不同光照时间和pH条件下的光稳定性。结果表明:随着光照时间的延长,硫量子点的荧光强度逐渐降低;与pH 7.4及11.0相比,硫量子点在pH 3.0条件下荧光强度下降较缓慢,具有更好的光稳定性。另外,在光照条件下,溶解氧会导致硫量子点的荧光发射峰强度降低且峰位蓝移,表明溶解氧对硫量子点的光稳定性也有非常重要的影响。

Sulfur quantum dots(SQDs)with high aqueous dispersion and stable fluorescence is synthesized by an H2O2-assisted etching top-down approach using polyethylene glycol-400 as passivation agents.The photostability of SQDs was systematically investigated by under different Xenon lamp irradiation time and pH conditions(pH 3.0,7.4 and 11.0).The results show that the fluorescence intensity of the SQDs gradually decreases as the irradiation time prolongs.Compared with pH 7.4 and pH 11.0,the fluorescence intensity of the SQDs decreases more slowly under the condition of pH 3.0,indicating that the SQDs has good photostability at pH 3.0.Dissolved oxygen was found resulting in decrease in fluorescence intensity and blue-shifted of fluorescence peak under Xenon lamp irradiation.It shows that dissolve oxygen plays an important role in the photostability of SQDs.