TY - JOUR
T1 - Glucose oxidase electrodes via reconstitution of the apo-enzyme
T2 - Tailoring of novel glucose biosensors
AU - Katz, Eugenii
AU - Riklin, Azalia
AU - Heleg-Shabtai, Vered
AU - Willner, Itamar
AU - Bückmann, A. F.
PY - 1999/4/5
Y1 - 1999/4/5
N2 - Reconstitution of an apo-flavoenzyme with a relay-FAD-cofactor dyad yields an electrically contacted enzyme, 'electroenzyme'. This is exemplified by the reconstitution of apo-glucose oxidase, apo-GOx, with a ferrocene-tethered FAD-cofactor. The resulting semisynthetic protein stimulates the bioelectrocatalyzed oxidation of glucose. Kinetic analysis of the ferrocene-FAD reconstituted enzyme reveals that its electrical communication with an electrode support is superior as compared to a protein randomly functionalized by ferrocene relay units. A pyrroloquinolinoquinone (PQQ)-FAD cofactor monolayer is assembled on a Au-electrode. Apo-GOx is reconstituted on the solid support to yield an aligned enzyme electrode of unprecendently efficient electrical contact. The electron-transfer turnover rate with the electrode is estimated to be 900±150s-1, a value close to the electron transfer rate between native GOx and molecular oxygen. The effective electrical communication of the integrated enzyme electrode stimulates the efficient bioelectrocatalyzed oxidation of glucose, and results in high current densities and high sensitivity for glucose. The effective electrical contact of the enzyme-electrode yields also a specific glucose sensing electrode that is not perturbed by oxygen or interferrants. The possible application of the enzyme-electrode as an invasive biosensor is addressed. Copyright (C) 1999 Elsevier Science B.V.
AB - Reconstitution of an apo-flavoenzyme with a relay-FAD-cofactor dyad yields an electrically contacted enzyme, 'electroenzyme'. This is exemplified by the reconstitution of apo-glucose oxidase, apo-GOx, with a ferrocene-tethered FAD-cofactor. The resulting semisynthetic protein stimulates the bioelectrocatalyzed oxidation of glucose. Kinetic analysis of the ferrocene-FAD reconstituted enzyme reveals that its electrical communication with an electrode support is superior as compared to a protein randomly functionalized by ferrocene relay units. A pyrroloquinolinoquinone (PQQ)-FAD cofactor monolayer is assembled on a Au-electrode. Apo-GOx is reconstituted on the solid support to yield an aligned enzyme electrode of unprecendently efficient electrical contact. The electron-transfer turnover rate with the electrode is estimated to be 900±150s-1, a value close to the electron transfer rate between native GOx and molecular oxygen. The effective electrical communication of the integrated enzyme electrode stimulates the efficient bioelectrocatalyzed oxidation of glucose, and results in high current densities and high sensitivity for glucose. The effective electrical contact of the enzyme-electrode yields also a specific glucose sensing electrode that is not perturbed by oxygen or interferrants. The possible application of the enzyme-electrode as an invasive biosensor is addressed. Copyright (C) 1999 Elsevier Science B.V.
KW - Biosensor
KW - Electrical contact of enzymes
KW - Enzyme monolayers
KW - FAD
KW - Flavin adenine dinucleotide
KW - Glucose oxidase
KW - Glucose sensor
KW - Integrated enzyme electrodes
KW - Reconstituted enzymes
UR - http://www.scopus.com/inward/record.url?scp=0032994640&partnerID=8YFLogxK
U2 - 10.1016/S0003-2670(98)00688-6
DO - 10.1016/S0003-2670(98)00688-6
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AN - SCOPUS:0032994640
SN - 0003-2670
VL - 385
SP - 45
EP - 58
JO - Analytica Chimica Acta
JF - Analytica Chimica Acta
IS - 1-3
ER -