Substrate Specificity and Interferences of a Direct-Electron-Transfer-Based Glucose Biosensor |
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Authors: | Alfons K G Felice Christoph Sygmund Wolfgang Harreither Roman Kittl Lo Gorton Roland Ludwig |
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Institution: | 1.Department of Food Science and Technology, Vienna Institute of Biotechnology, BOKU—University of Natural Resources and Life Sciences, Vienna, Austria;2.DirectSens GmbH, Klosterneuburg, Austria;3.Department of Analytical Chemistry, Biochemistry and Structural Biology, Lund University Lund, Sweden |
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Abstract: | Objective:Electrochemical sensors for glucose monitoring employ different signal transduction strategies for electron transfer from the biorecognition element to the electrode surface. We present a biosensor that employs direct electron transfer and evaluate its response to various interfering substances known to affect glucose biosensors.Methods:The enzyme cellobiose dehydrogenase (CDH) was adsorbed on the surface of a carbon working electrode and covalently bound by cross linking. The response of CDH-modified electrodes to glucose and possible interfering compounds was measured by flow-injection analysis, linear sweep, and chronoamperometry.Results:Chronoamperometry showed initial swelling/wetting of the electrode. After stabilization, the signal was stable and a sensitivity of 0.21 μA mM−1 cm−2 was obtained. To investigate the influence of the interfering substances on the biorecognition element, the simplest possible sensor architecture was used. The biosensor showed little (<5% signal deviation) or no response to various reported electroactive or otherwise interfering substances.Conclusions:Direct electron transfer from the biorecognition element to the electrode is a new principle applied to glucose biosensors, which can be operated at a low polarization potential of −100 mV versus silver/silver chloride. The reduction of interferences by electrochemically active substances is an attractive feature of this promising technology for the development of continuous glucose biosensors. |
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Keywords: | biosensors cellobiose dehydrogenase continuous glucose measurement direct electron transfer interference selectivity |
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