title: Substrate specificity and interferences of a direct-electron-transfer-based glucose biosensor.
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.
authors.affiliation: Department of Food Science and Technology, Vienna Institute of Biotechnology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 11/1/56, Vienna, Austria.
authors.forename: Alfons K G
authors.initials: AK
authors.lastname: Felice
authors.forename: Christoph
authors.initials: C
authors.lastname: Sygmund
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Harreither
authors.forename: Roman
authors.initials: R
authors.lastname: Kittl
authors.forename: Lo
authors.initials: L
authors.lastname: Gorton
authors.forename: Roland
authors.initials: R
authors.lastname: Ludwig
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002237:Carbohydrate Dehydrogenases; D004563:Electrochemistry; D004566:Electrodes; D004583:Electrons; D004800:Enzymes, Immobilized; D005947:Glucose / Q000032:analysis*; D013379:Substrate Specificity
chemical_list: D004800:Enzymes, Immobilized; D002237:Carbohydrate Dehydrogenases; C019859:cellobiose-quinone oxidoreductase; D005947:Glucose