Total internal reflected resonance light scattering detection of DNA at water/tetrachloromethane interface with acrindine orange and cetyltrimethylammonium bromide Original Research Article

Total internal reflected resonance light scattering (TIR-RLS) technique is employed to detect DNA at the water/tetrachloromethane (H2O/CCl4) interface with good selectivity and sensitivity. At pH 7.56 and ionic strength 0.007 M and in the presence of cetyltrimethylammonium bromide (CTMAB), the interaction of acrindine orange (AO) with with DNAs, including calf thymus DNA (ctDNA) and fish sperm DNA (fsDNA), results in strong enhanced TIR-RLS signals with the maximum peak located at 368.0 nm. The enhanced TIR-RLS intensity at 368.0 nm was found to be proportional to the concentration of ctDNA and fsDNA in the range 0.0032–2.0 and 0.0025–2.4 μg ml−1, respectively, and the limits of determination (3σ) are 0.32 and 0.25 ng ml−1, correspondingly. Artificial samples with highly interfering backgrounds have been analyzed satisfactorily.