Enhancement of catalytic efficiency of enzymatic redox reaction by composing a horseradish peroxidase-modified electrode with ionic liquids

Abstract We have kinetically estimated the redox reaction at the horseradish peroxidase (HRP)-modified electrode combined with ionic liquids by adding N-(2-methoxythethyl)-N-methylpyrrolidinium bis(trifluoromethane sulfonyl)imide (MEMPTFSI) to HRP/carbon paste (CP)/Ketjenblack EC600JC (EC). The redox reaction at the HRP/CP/EC/MEMPTFSI-modified electrode and the HRP/CP-modified electrode could be correlated by Michaelis-Menten equation. Michaelis constant of the redox reaction at the HRP/CP/EC/MEMPTFSI-modified electrode was the same as that at the HRP/CP-modified electrode. On the other hand, the turnover number of the redox reaction at the HRP/CP/EC/MEMPTFSI-modified electrode was six times larger than that at the HRP/CP-modified electrode. Consequently, the specific constant of the redox reaction at the HRP/CP/EC/MEMPTFSI-modified electrode was much higher than that at the HRP/CP-modified electrode.