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Spectroelectrochemical Study of N ‐Substituted Phenoxazines as Electrochemical Labels of Biomolecules
Author(s) -
Kulys Juozas,
Vidziunaite Regina,
Janciene Regina,
Palaima Algis
Publication year - 2006
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200603604
Subject(s) - electrochemistry , chemistry , electrolysis , redox , cyclic voltammetry , electrode , biomolecule , inorganic chemistry , biochemistry , electrolyte
The electrochemical conversion of N ‐substituted phenoxazines (NSP's) bearing a CH 2 CH 2 X substitute (where XOH, COOH, CH 2 NH 2 , CH 2 SO 3 H, CH 2 NHCOR) was investigated using cyclic voltammetry on a bulk gold electrode and a thin‐layer spectroelectrochemical cell. The electrochemical oxidation of NSP's on the gold electrode was quasi‐reversible and proceeded in a diffusion‐controlled regime. The formal redox potential of NSP's covered the range from 0.39 to 0.45 V vs. SCE. The electrochemical oxidation of NSP's in the thin‐layer spectroelectrochemical cell produced radical cations that showed absorbance at 385, 410 and 530 nm. Electrochemical conversion fitted the general voltammetric current‐potential equation of a reversible wave, whereas electrolysis at constant potential showed a typical Cottrell behavior. Combining of NSP's with a biologically‐relevant theophylline molecule did not change electrochemical and spectral properties of the phenoxazine core. Theophylline enlarged with NSP's demonstrated electrochemical and biocatalytic behavior similar to that of NSP's. The investigated NSP's possess electrochemical and spectral properties that are useful as biomolecular labels for electroanalysis.