Spectroscopy studies of sandwich-type complex of silver(I) co-ordinated to nuclear fast red and adenine and its analytical applications

A novel fluorometric method for the determination of adenine was proposed, based on the fluorescence quenching of a nuclear fast red-silver complex as a small molecule optical probe in the presence of adenine. The characteristic spectra of absorption, resonance Rayleigh scattering (RRS) and the fluorescence of the system were analysed. Adenine, Ag⁺ and nuclear fast red formed a sandwich-type complex. The composition of the compound and the mechanisms of fluorescence quenching were discussed. The optimal conditions for the reaction and the effects of co-existing substances were also investigated. The quenched fluorescence intensity was proportional to the concentration of adenine in the range of 0.03–0.90 µg mL^?1, with the limit of detection of 0.023 µg mL^?1. The method was applied satisfactorily to the determination of adenine in synthetic samples, herring sperm DNA, human sera and vitamin B₄ tablets with recoveries from 95.3 % to 105 %.