Study on the Interaction of Alaminum Ion with Deoxyribonucleic Acid by Resonance Light Scattering Measurement
In an acidic medium of pH2.21, the interaction of Al~(3+) with deoxyribonucleic acid (DNA) results in enhanced resonance light scattering (RLS) spectra characterized by a peak at 291 nm. That is, Al~(3+) is mainly in combination with phosphate ion of the surface of DNA molecule. Thermally denaturation of double stranded DNA will lead to interaction Al~(3+) with base of DNA, and will decreased th RLS signals. It was found that under the optimal condition the enhanced RLS intensity at 291.0 nm was proportional to the concentration of DNA, and a RLS method for the determination of trace DNA was accordingly established. The limit of determination was nanogram level. The present method was successfully applied to the determination of DNA in synthetic samples with the recovery of 91.6%～105.0%.