Authors: Haitao Zheng Jingli Zhou Jimei Zhang Rong Huang Hailian Jia Shinichiro Suye
Publish Date: 2008/10/07
Volume: 165, Issue: 1-2, Pages: 109-115
Abstract
A ferrocenelabeled high molecular weight cofactor derivative PEIFcNAD was prepared by attaching both ferrocene and nicotinamide adenine dinucleotide NAD+ to a water soluble polyelectrolyte polyethylenimine PEI Approximately 98 and 29 of all the primary amino groups of PEI were coupled with ferrocene and the bioactive cofactor respectively The cyclic voltammograms of PEIFcNAD exhibited a oneelectron transfer process and the difference between the anodic and cathodic peak potential was found to be 80 mV The PEIFcNAD was used together with NADdependent dehydrogenase to construct a reagentless biosensor An NADdependent alcohol dehydrogenase ADH was selected as the model enzyme and both ADH and PEIFcNAD were retained onto the sensing area of gold electrodes by a dialysis membrane or immobilized by layerbylayer adsorption method In both cases the modified electrodes showed current response to ethanol without the addition of native NAD+ to the system which suggested that the electrical communication between ADH and the electrode was achieved through PEIFcNAD In summary PEIFcNAD provides a new way for immobilization of mediator and cofactor and exhibits the potential as a platform for constructing reagentless NADdependent dehydrogenase biosensorsThe research was supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars State Education Ministry Natural Science Foundation of Tianjin No 06YFJMJC15000 and the Innovation Funs from Tianjin Polytechnic University
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