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Effect of Enzyme and Cofactor Immobilization on the Response of Ethanol Oxidation in Zirconium Phosphate Modified Biosensors
Author(s) -
Santiago Mitk'El B.,
Daniel Gabriel A.,
David Amanda,
Casañas Barbara,
Hernández Griselle,
Guadalupe Ana R.,
Colón Jorge L.
Publication year - 2010
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.200900329
Subject(s) - biosensor , nafion , chemistry , nicotinamide adenine dinucleotide , amperometry , alcohol dehydrogenase , glassy carbon , cofactor , inorganic chemistry , nad+ kinase , zirconium phosphate , carbon paste electrode , ethanol , nuclear chemistry , electrode , phosphate , cyclic voltammetry , organic chemistry , electrochemistry , biochemistry , enzyme
Two different self‐contained ethanol amperometric biosensors incorporating layered [Ru(phend) 2 bpy] 2+ ‐intercalated zirconium phosphate (ZrP) as the mediator as well as yeast ‐alcohol dehydrogenase ( y‐ ADH) and its cofactor nicotinamide adenine dinucleotide (NAD + ) were constructed to improve upon a design previously reported where only this mediator was immobilized in the surface of a modified electrode. In the first biosensor, a [Ru(phend) 2 bpy] 2+ ‐intercalated ZrP modified carbon paste electrode (CPE) was improved by immobilizing in its surface both y‐ ADH and NAD + using quaternized Nafion membrane. In the second biosensor, a glassy carbon electrode was modified with [Ru(phend) 2 bpy] 2+ ‐intercalated ZrP, y‐ ADH, and NAD + using Nafion as the holding matrix. Calibration plots for ethanol sensing were constructed in the presence and absence of ZrP. In the absence of ZrP in the surface of the modified glassy carbon electrode, leaching of ADH was observed as detected by UV‐vis spectrophotometry. Ethanol sensing was also tested in the presence and absence of ascorbate to measure the selectivity of the sensor for ethanol. These two ethanol biosensors were compared to a previously reported one where the y ‐ADH and the NAD + were in solution, not immobilized.