Interaction of Spectral Probe with Biomacromolecule: Safranin T-Nucleic Acid Assembly

Abstract The microsurface–spectral correction (MSASC) technique has been described and applied to study the assembly of safranin T on nucleic acids at pH 2.21. The formation of the electrostatic film in nucleic acids causes the aggregation of small molecules and the aggregation obeys the Langmuir isothermal adsorption. The characterization of the assembly complexes was made. Results have showed that the maximal assembly number of ST is 1.62 on each phosphate in deoxyribonucleic acid and 0.84 on each phosphate in ribonucleic acid and the binding constants of the complexes are K DNA-P-ST = 2.11 × 104 and K RNA-P-ST = 1.41 × 104 L mol−1. This aggregation was applied to the quantitative detection of nucleic acids in samples with satisfactory results.