Optimization of aflatoxin B removal efficiency of DNA by resonance light scattering spectroscopy.

In this paper, firstly, the resonance light scattering spectra of aflatoxin B (AFB) and DNA were measured by resonance light scattering spectroscopy (RLS), and the DNA binding saturation value (DBSV) of AFB was calculated from their spectral results. Then the interaction intensity between DNA and AFB and the effects of some external factors on the interaction between DNA and AFB were evaluated by corresponding DBSVs, so as to establish and optimize a way for removing AFB by DNA. DBSV of AFB was 2.04 at 30℃ and pH 7.40. However, after adding sodium ion, calcium ion, vitamin E, vitamin C and D-glucose, DBSV of AFB was changed to 2.72, 3.17, 2.67, 1.68 and 1.33 respectively. Correspondingly, the removal efficiency of AFB by DNA was changed from 90.05% to 93.25%, 95.48%, 93.08%, 82.36% and 78.90% respectively. These results indicated that the external factors had a significant impact on the interaction between DNA and AFB. Among them, some factors enhanced the interaction between DNA and AFB, while some factors weakened the interaction between DNA and AFB1. The change of these external factors led to the corresponding changes in DBSV and the removal efficiency of AFB. DBSV of AFB could really be used as an index to evaluate the intensity of the interaction between DNA and AFB, and to optimize the removal efficiency of AFB by DNA. The experimental data also showed that the adsorption of AFB to DNA was consistent with the pseudo-second-order kinetic model and the Freundlich isothermal model, was an exothermic and spontaneous process. All these results will give good references for establishing and optimizing a way of AFB removal via DNA intercalation.