Super – Fluorescence Quenching of 1-(E)-styryl-2-(4-(2-(E) - styrylphenoxy) Butoxy)Benzene (Alkoxy Bridged Styryl Benzene)(PPPBB) Colloidal Silver and Gold Nanoparticles

Abstract

The Super-efficient fluorescence quenching of the dye, 1-(E)-styryl-2-(4-(2-(E)-styrylphenoxy) butoxy) benzene (alkoxy bridged styryl benzene) (PPPBB), by silver and gold nanoparticles (Ag NPs and Au NPs) are explored by the steady-state fluorescence measurements in methanol and ethylene glycol (MeOH and EG). The data showed that both radiative and non-radiative energy-transfer perform a key role in the fluorescence super-quenching mechanism. The Stern–Volmer quenching constants (Ksv) were calculated as 1.4 \(\times\) 1010, 1.2 \(\times\) 1010 M− 1 in MeOH and EG for Ag NPs, and 2.69 \(\times\) 108, 6.18 \(\times\) 109 M− 1 in MeOH and EG for Au NPs, respectively. Besides, the quenching sphere radius (r) values were calculated, via Perrin model of quenching, as 160,161 nm in MeOH and EG for Ag NPs, and 45, 85 nm in MeOH and EG for Au NPs, respectively. From active sphere radius results, one can conclude that the fluorescence resonance energy-transfer is responsible for super-quenching of PPPBB. Moreover, the fluorescence energy-transfer had an observable effect on the fluorescence super-quenching of PPPBB by AgNPs and AuNPs in EG more than in MeOH. These Super-quenching processes can pave the way for the usage of (PPPBB/ NPs) quenching systems in the energy transfer-based biosensors and essays with high degree of sensitivity.