Switch-Off fluorescence of 5-amino-2-mercapto benzimidazole with Ag3O4 nanoparticles: Experimental and theoretical investigations
Abstract The binding interaction of 5-amino-2-mercaptobenzimidazole (AMB) with Ag 3 O 4 nanoparticles was studied. AMB adsorbs strongly on the surfaces of nano semiconductor. The interaction of AMB with Ag 3 O 4 was studied by absorption, fluorescence, FT-IR, SEM and EDX spectral studies. The Ag 3 O 4 nanoparticles were synthesized by chemical route and was characterized by XRD study. Excellent results observed were due to electron transfer between AMB and Ag 3 O 4 nanoparticles. To confirm the binding site of Ag 3 O 4 with AMB, molecular electrostatic potential (MEP) study was carried out theoretically. It confirmed the higher electron density at azomethine nitrogen atom. Photo-induced electron transfer is responsible for fluorescence quenching of AMB. The interaction between AMB and Ag 3 O 4 occurs through static quenching mechanism. The apparent association constant ( K app  = 2.0 × 10 5  M −1 ) was obtained from the fluorescence quenching data.