A resonance Rayleigh scattering detection of DNA hybridization based on interaction between DNA and surfactants

Abstract

We developed a new method that used surfactants to detect DNA hybridization in aqueous media, this method is highly sensitive and based on a resonance Rayleigh scattering (RRS) technique. Cationic surfactants, cetyltrimethyl ammonium bromide (CTAB) and cetylpyridinebromide (CPB), anionic surfactants, sodium dodecylbenzene sulphonate (SDBS) and sodium dodecyl sulphonate (SDS), nonionic surfactants Triton-100 (TX-100) and Tween-80 (T-80), interacted with double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA), and were investigated respectively. The RRS signal was strongest in the case of the CTAB complex which therefore was selected as the probe. Based on the RRS data, a linear relation between RRS intensity and target DNA concentration was found. Mechanism investigations have shown that CTAB can bind to DNA by electrostatic and hydrophobic interactions and aggregate on the molecular surface of dsDNA at pH 7.2. By using CTAB as a probe, we detected and analyzed two kinds of characteristic sequences.