TY - JOUR
T1 - Electron-transfer studies with a new flavin adenine dinucleotide dependent glucose dehydrogenase and osmium polymers of different redox potentials
AU - Zafar, Muhammad Nadeem
AU - Wang, Xiaoju
AU - Sygmund, Christoph
AU - Ludwig, Roland
AU - Leech, Dónal
AU - Gorton, Lo
PY - 2012/1/3
Y1 - 2012/1/3
N2 - A new extracellular flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase from Glomerella cingulata (GcGDH) was electrochemically studied as a recognition element in glucose biosensors. The redox enzyme was recombinantly produced in Pichia pastoris and homogeneously purified, and its glucose-oxidizing properties on spectrographic graphite electrodes were investigated. Six different Os polymers, the redox potentials of which ranged in a broad potential window between +15 and +489 mV versus the normal hydrogen electrode (NHE), were used to immobilize and "wire" GcGDH to the spectrographic graphite electrode's surface. The GcGDH/Os polymer modified electrodes were evaluated by chronoamperometry using flow injection analysis. The current response was investigated using a stepwisely increased applied potential. It was observed that the ratio of GcGDH/Os polymer and the overall loading of the enzyme electrode significantly affect the performance of the enzyme electrode for glucose oxidation. The best-suited Os polymer [Os(4,4′-dimethyl-2,2′-bipyridine) 2(PVI)Cl] + had a potential of +309 mV versus NHE, and the optimum GcGDH/Os polymer ratio was 1:2 yielding a maximum current density of 493 · cm -2 at a 30 mM glucose concentration.
AB - A new extracellular flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase from Glomerella cingulata (GcGDH) was electrochemically studied as a recognition element in glucose biosensors. The redox enzyme was recombinantly produced in Pichia pastoris and homogeneously purified, and its glucose-oxidizing properties on spectrographic graphite electrodes were investigated. Six different Os polymers, the redox potentials of which ranged in a broad potential window between +15 and +489 mV versus the normal hydrogen electrode (NHE), were used to immobilize and "wire" GcGDH to the spectrographic graphite electrode's surface. The GcGDH/Os polymer modified electrodes were evaluated by chronoamperometry using flow injection analysis. The current response was investigated using a stepwisely increased applied potential. It was observed that the ratio of GcGDH/Os polymer and the overall loading of the enzyme electrode significantly affect the performance of the enzyme electrode for glucose oxidation. The best-suited Os polymer [Os(4,4′-dimethyl-2,2′-bipyridine) 2(PVI)Cl] + had a potential of +309 mV versus NHE, and the optimum GcGDH/Os polymer ratio was 1:2 yielding a maximum current density of 493 · cm -2 at a 30 mM glucose concentration.
UR - http://www.scopus.com/inward/record.url?scp=84855365640&partnerID=8YFLogxK
U2 - 10.1021/ac202647z
DO - 10.1021/ac202647z
M3 - Article
SN - 0003-2700
VL - 84
SP - 334
EP - 341
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 1
ER -