Study on the interaction of nucleic acids with silver nanoparticles—Al(III) by resonance light scattering technique and its analytical application

It is found that Al(III) can further enhance the intensity of resonance light scattering (RLS) of the silver nanoparticles (AgNPs) and nucleic acids system. Based on this, a novel method of determination of nucleic acids is proposed in this paper. Under optimum conditions, there are linear relationships between the enhancing extent of RLS and the concentration of nucleic acids in the range of 1.0 × 10−9–1.0 × 10−7 g mL−1, 1.0 × 10−7–2.0 × 10−6 g mL−1 for fish sperm DNA (fsDNA), 1.0 × 10−9–7.0 × 10−8 g mL−1 for calf thymus DNA (ctDNA) and 1.0 × 10−9–1.0 × 10−7 g mL−1 for yeast RNA (yRNA). The detection limits (S/N = 3) of fsDNA, ctDNA and yRNA are 4.1 × 10−10 g mL−1, 4.0 × 10−10 g mL−1 and 4.5 × 10−10 g mL−1, respectively. The studies indicate that the RLS enhancement effect should be ascribed to the formation of AgNPs–Al(III)–DNA aggregations through electrostatic attraction and adsorption bridging action of Al(III). And the sensitivity and stability of the AgNPs–fsDNA system could be enhanced by Al(III).