Sensitive determination of DNA based on resonance light scattering enhancement of azocarmine G and CTAB

Abstract

A new method for the determination of DNA was developed with azocarmine G(AG) in the presence of cetyltrimethylammonium bromide(CTAB) by the resonance light scattering (RLS) technique. The synthetic samples were determined with satisfactory results, and the reaction mechanism was also studied. The results show that under the optimum conditions, the weak RLS signal of AG can be enhanced by DNA, which results from the formation of a new ternary complex AG-CTAB-DNA with large size. Moreover, the enhanced RLS intensity at 552 nm is directly proportional to the concentration of DNA in the range of 0–1.0 µg/mL for fish sperm DNA (fsDNA) and 0–1.5 µg/mL for calf thymus DNA (ctDNA). Based on this, a new assay of DNA can be established. The detection limits (3σ) are 2.1 ng/mL for fsDNA and 2.2 ng/mL for ctDNA, respectively.

Keywords

determination / resonance light scattering / azocarmine G / DNA / cetyltrimethylammonium bromide