Use of coumarin derivatives as activators in the peroxyoxalate system in organic and aqueous media

Autor: Wilhelm J. Baader, Maidileyvis Castro Cabello, Liena Valero Bello
Rok vydání: 2021
Předmět:
Zdroj: Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
ISSN: 1010-6030
DOI: 10.1016/j.jphotochem.2020.113076
Popis: The peroxyoxalate system – base catalyzed reaction of oxalic ester derivatives with hydrogen peroxide in the presence of a fluorescent activator – is one of the most efficient chemiluminescence transformations known and widely utilized in analytical and bioanalytical applications. Coumarin derivatives have found widespread application as fluorescent labels for the determination of enzymatic activity in biological fluids and in fluorescence immunoassays, among others. In this work, we show that coumarin derivatives can be utilized as activators in the peroxyoxalate reaction (with two oxalic esters, including a new, environmentally compatible derivative) in anhydrous and aqueous systems, leading to reproducible kinetic results and singlet quantum yields similar to that obtained with commonly utilized activators. Quantum yields are lower in aqueous than in anhydrous medium, however still considerably high to allow the application in analytical and bioanalytical assays. The chemiluminescence parameters (singlet quantum yields at infinite activator concentration and relative electron transfer rate constants) determined in the systems indicate the occurrence of electron or charge transfer steps according to the Chemically Initiated Electron Exchange Luminescence (CIEEL) mechanism.
Databáze: OpenAIRE