Deactivation of bilirubin oxidase by a product of the reaction of urate and O2.
The "wired" bilirubin oxidase (BOD) bioelectrocatalyst is superior to pure platinum as an electrocatalyst of the four-electron electroreduction of O(2) to water. Not only is its overpotential for O(2) reduction lower, but unlike platinum, it is not affected by organic compounds like glucose. The "wired" BOD-coated carbon cathode operates for >1 week at 37 degrees C in a glucose-containing physiological buffer solution. One of its key applications would be in a glucose-O(2) biofuel cell, which would operate in living tissues. The cathode is, however, short-lived in serum, losing its electrocatalytic activity in a few hours. Here we show that the damaging serum component is a product of the reaction of urate and dissolved oxygen. Exclusion of urate, by application of Nafion film on the cathode, improves the stability in serum.
Kang
Chan
C
Department of Chemistry, Chonbuk National University, Chonju 561-756, Korea.
Shin
Hyosul
H
Zhang
Yongchao
Y
Heller
Adam
A
D002384:Catalysis; D002413:Cations, Divalent / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D004789:Enzyme Activation / Q000187:drug effects; D007093:Imidazoles / Q000737:chemistry; D010084:Oxidation-Reduction; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D010100:Oxygen / Q000737:chemistry* / Q000494:pharmacology; D011489:Protein Denaturation; D014527:Uric Acid / Q000737:chemistry* / Q000494:pharmacology
D002413:Cations, Divalent; D007093:Imidazoles; D014527:Uric Acid; D003300:Copper; C029899:imidazole; D044925:Oxidoreductases Acting on CH-CH Group Donors; C042401:bilirubin oxidase; D010100:Oxygen