Simultaneous Determination of the Chemical (kr) and the Physical (kq) Quenching Rate Constants of Singlet Oxygen in Aqueous Solution by the Chemiluminescence-quenching Method†

被引:3
作者
Pierlot, Christel [1 ]
Nardello-Rataj, Veronique [1 ]
Aubry, Jean-Marie [1 ]
机构
[1] Univ Artois, Univ Lille, Cent Lille, CNRS,UMR 8181,UCCS, Lille, France
关键词
HYDROGEN-PEROXIDE; MOLECULAR-OXYGEN; NAPHTHALENE DERIVATIVES; DISPROPORTIONATION; GENERATION; CARRIERS; MECHANISMS; OXIDATION; SEARCH;
D O I
10.1111/php.13471
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
This work reports a novel and visual method for the simultaneous determination of the chemical (k(r)) and the physical (k(q)) quenching rate constants of singlet oxygen (O-1(2),(1) increment (g)) in aqueous media. It is based on the disruption, by a water-soluble substrate S, of the O-1(2) chemiluminescence (CL) generated by the H2O2/Na2MoO4 catalytic system. A mathematical analysis of the CL signal at 1270 nm vs time provides separately the overall (k(r) + k(q)) and the chemical (k(r)) quenching rate constants. In ordinary water (H2O), O-1(2) lifetime is short and the CL intensity is weak allowing solely the investigation of very reactive substrates for which (k(r) + k(q)) > 3 x 10(6) m(-1) s(-1) while, in D2O, O-1(2) lifetime is significantly longer lifetime and the CL signal is much stronger allowing the study of poorly reactive substrates for which (k(r) + k(q)) > 4 x 10(5) m(-1) s(-1). The method has been successfully tested on a series of anionic and nonionic water-soluble naphthalene derivatives commonly used as bio-compatible O-1(2) carriers. The obtained k(r) and k(q) values are in good agreement with the values determined by conventional techniques, namely, flash photolysis and competitive kinetics with a reference quencher.
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页码:1343 / 1352
页数:10
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