Elucidating the Mechanism of Copper-Induced Photoluminescence Quenching in 2-Phenylbenzimidazole-5-Sulfonic Acid.
J Fluoresc
; 2024 Apr 29.
Article
en En
| MEDLINE
| ID: mdl-38683267
ABSTRACT
To explore the possible impact of 2-Phenylbenzimidazole-5-sulfonic acid (PBSA) on the function of a sunscreen, in this work we investigate the binding of copper metal ions (Cu2+) to PBSA. Due to the existence of an intrinsic interaction phenomenon between Cu2+ ions and PBSA molecules, the photoluminescence (PL) quenching arises owing to the charge transfer from PBSA to Cu2+ ions. The mechanism of fluorescence quenching is probed experimentally following excitation at 306 nm by evaluating various quenching parameters with the help of the Stern-Volmer plot. Through the assessment of the values of the Stern-Volmer constant ( K SV = 45.2 M - 1 ) and bimolecular quenching rate constant ( k q = 0.77 × 10 10 M - 1 . s - 1 ), it is deduced that the dynamic mode of PL quenching is operative between PBSA and Cu2+ ions. We evaluate the number of binding sites (n = 1) that advocate the presence of a single binding site in PBSA for Cu2+ ions. The numerical value of standard Gibbs free energy change, Δ G o ~ -27.485 kJ.mol-1 implies the spontaneous binding between Cu2+ ions and PBSA molecules. The results obtained give an insight into the mechanism of metal-induced PL quenching of water soluble PBSA sunscreen.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
J Fluoresc
Asunto de la revista:
BIOFISICA
Año:
2024
Tipo del documento:
Article
País de afiliación:
Pakistán
Pais de publicación:
Países Bajos