Abstract: 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.

Key words: DNA/CdS nanoparticle composites, Photoelectrochemical property, Spectroscopic property