Spectral studies on the interaction of Amido black 10B with DNA in the presence of cetyltrimethylammonium bromide.
The interaction of Amido black 10B (AB) with DNA in basic medium was studied in the presence of cetyltrimethylammonium bromide (CTMAB) based on the measurements of resonance light scattering (RLS), UV-vis, CD spectra, and RLS imaging. The interaction has been proved to give a ternary complex of CTMAB-DNA-AB in Britton-Robinson buffer of pH 11.55, which exhibits strong negative Cotton effect at 233.3nm and 642.8nm, and strong RLS signals characterized at 469nm. Experiments showed that the enhanced RLS intensities (DeltaI(RLS)) against the mixture of AB and CTMAB are proportional to the concentration of fish sperm DNA (fsDNA) and calf thymus DNA (ctDNA), respectively over the range of 0.03-1.0 and 0.05-1.5microg ml(-1), with the limits of determination (3sigma) of 7.3ng ml(-1) for fsDNA and 7.0ng ml(-1) for ctDNA.
Long
Yun Fei
YF
College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
Huang
Cheng Zhi
CZ