DNA/CdS纳米粒子复合体系的光谱和光电化学性质

Spectroscopic and Photoelectrochemical Properties of DNA/CdS Nanoparticle Composites

在水溶液中以DNA作为模板和稳定剂,构筑了DNA与CdS纳米粒子复合体系(DNA/CdSNPC),研究DNA的含量,单双链等对复合体系光电响应的影响,并综合TEM,UV-Vis,IR和荧光光谱等对其形貌和光谱性质进行表征.结果表明,CdS纳米粒子(CdSNPs)与DNA链之间主要通过静电作用结合;DNA模板对CdSNPs的禁带宽度没有影响;以DNA模板合成的CdSNPs具有较高的表面态密度,其对CdSNPs的荧光有增强作用,而对光电流响应有抑制作用,并且DNA在复合体系中的含量影响荧光增强和光电流减弱的程度.该复合体系在荧光标记检测和DNA的定量分析方面可能具有应用前景.

DNA/CdS nanoparticle composites （DNA/CdS NPC） containing single or double strands and different concentrations of DNA were constructed in aqueous solutions. The effect of DNA on the photoelectrochemical properties of DNA/CdS NPC was investigated and the spectroscopic properties of DNA/CdS NPC were characterized by TEM, UV-Vis, IR, and fluorescent spectrometry. The results showed that CdS nanoparticles （CdS NPs） were combined with DNA strands through the electrostatic interaction; DNA templates did not affect the band gap of CdS NPs; DNA-templated CdS NPs had a higher density of surface states than that stabilized by Na4P2O7, which enhanced the photoluminescence （PL） intensity whereas restrained the photocurrent response of CdS NPs. Besides, there was certain dependency of both the increase of PL intensity and the decrease of photocurrent response on DNA concentrations in DNA/CdS NPC. The composites were hopeful for applications in both fluorescent tagged detections and quantitative analysis of DNA.