Reagentless recycling of pyruvate oxidase on a conducting polymer-modified electrode

Electrochemical Recycling of Adenosine Triphosphate in Biocatalytic Reaction Cascades

“…Using the formalism introduced by Saveant et al , the rate constant for the oxidation of PO by the oxidized FcMeOH can be extracted, giving a value of 1.0 × 10 5 M –1 s –1 , similar to the previously reported value for FcMeOH (1.5 × 10 5 M –1 s –1 ) . Interestingly, this rate is also similar to that previously measured for the oxidation of PO with molecular O 2 (1.7 × 10 5 M –1 s –1 ), , suggesting that the turnover of PO by a redox mediator is possible at competitive rates. When PO is depleted of FAD, we observe a decrease in the oxidation rate (Table , entry 11), which suggests that the mediator oxidizes FADH 2 and not TPP (Scheme ).…”

“…However, in the presence of PO, a catalytic S-shaped curve is observed, indicating the turnover of the enzyme by the mediator (Figure ). Using the formalism introduced by Saveant et al , the rate constant for the oxidation of PO by the oxidized FcMeOH can be extracted, giving a value of 1.0 × 10 5 M –1 s –1 , similar to the previously reported value for FcMeOH (1.5 × 10 5 M –1 s –1 ) . Interestingly, this rate is also similar to that previously measured for the oxidation of PO with molecular O 2 (1.7 × 10 5 M –1 s –1 ), , suggesting that the turnover of PO by a redox mediator is possible at competitive rates.…”

Electrochemical Recycling of Adenosine Triphosphate in Biocatalytic Reaction Cascades

“…Using the formalism introduced by Savéant et al 13 , the rate constant for the oxidation of PO by the oxidized FcMeOH can be extracted, giving a value of 1.2 x 10 5 M -1 s -1 , similar to the previously reported value for FcMeOH (1.5 x 10 5 M -1 s -1 ). ( 16) Interestingly, this rate is also similar to that previously measured for oxidation of PO with molecular O2 (1.7 x 10 5 M -1 s -1 ), 17,22 suggesting that turnover of PO by a redox mediator is possible at competitive rates. ( 21) Within the ranges studied, the observed oxidation rate is independent of both mediator oxidation potential and pH, since similar rates are observed with ferrocene derivatives with oxidation potentials ranging from 0.25 to 0.48 V vs. Ag/AgCl (Table S1) and from pHs ranging from 6.0 to 7.5 (Table S2).…”

Electrochemical kinetic analysis of a 1,4-hydroxynaphthoquinone self-assembled monolayer

“…Transduction can be performed using the intrinsic electroactivity of the polymer backbone [11][12][13]. Our group is currently concerned with devices based on functionalized conducting polymers modified electrodes, in view of applications in enzymes [14][15][16] and DNA electrochemical sensors [17][18][19].…”