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Long‐lasting chemiluminescence of luminol on electrochemically pre‐oxidized platinum electrodes in NaOH solution
Author(s) -
Lin XiangQin,
Sun YuGang,
Cui Hua
Publication year - 2000
Publication title -
luminescence
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.428
H-Index - 45
eISSN - 1522-7243
pISSN - 1522-7235
DOI - 10.1002/1522-7243(200009/10)15:5<299::aid-bio598>3.0.co;2-i
Subject(s) - luminol , chemiluminescence , electrode , platinum , chemistry , redox , polarization (electrochemistry) , electrode potential , catalysis , inorganic chemistry , analytical chemistry (journal) , electrochemistry , chromatography , organic chemistry
A long‐lasting bright chemiluminescence (CL) of luminol was generated at polycrystalline platinum electrodes with open circuit. The CL can last for several hours with the presence of O 2 in the solution when the electrode was preoxidized at potentials more positive than 1.10 V vs. SCE. The effects of the varieties of solution conditions and surface states of the electrode on the CL intensity and the interfacial potential of the electrode were investigated. It was proposed that PtO was generated at the pre‐oxidized potentials and played a role of catalyst of luminol oxidation for generating the CL. The redox couple of PtO/Pt active at the electrode surface was maintained in the presence of O 2 and luminol, and generated the interfacial potential more positive than 140 mV. Mathematical treatment of the reaction mechanism was conducted, which led to an approximated expression of a steady CL intensity ( I CL ) as a function of the pre‐polarization potential ( E h ) and time (τ h ) of the electrode. An empirical equation, ( I CL ) 4/3 = 3480(−1 + 0.82 E h + 0.037 ln τ h ), was estimated from the experimental data. Copyright © 2000 John Wiley & Sons, Ltd.