Development of Redox Sensors for Environmental Applications Based on Immobilized Redox Indicators

Autor:	T. L. Lemmon, Jr. J. D. Ingle, and J. C. Westall
Rok vydání:	1996
Předmět:	Absorption spectroscopy Standard hydrogen electrode medicine.diagnostic_test Chemistry Inorganic chemistry Analytical chemistry Electrochemistry Redox Thionine Analytical Chemistry Redox indicator chemistry.chemical_compound Affinity chromatography Spectrophotometry medicine
Zdroj:	Analytical Chemistry. 68:947-953
ISSN:	1520-6882 0003-2700
DOI:	10.1021/ac950885a
Popis:	Two redox indicators, thionine and phenosafranine, were successfully immobilized on an affinity chromatography gel and were shown to retain their redox activity. The formal potentials (versus the standard hydrogen electrode) near pH 7 were determined to be 52 mV for immobilized thionine and −286 mV for immobilized phenosafranine. It was demonstrated that the immobilized indicators can be packed in a flow cell and monitored spectrophotometrically to determine their speciation. The absorption spectra and electrochemical behavior of the indicators were only slightly affected by immobilization on the gel. For both indicators, immobilization caused the formal potential to decrease (15−20 mV) and the absorption spectrum to shift to higher wavelengths (20−40 nm) with respect to the free (unbound) indicators. These immobilized redox indicators couple with some redox-active species [Cr(VI), O2, and Fe(II)] that are important in environmental samples.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::a300517b550200d44fadb3d2ce9cc40f https://doi.org/10.1021/ac950885a Zobrazit plný text záznamu