d-Fructose detection based on the direct heterogeneous electron transfer reaction of fructose dehydrogenase adsorbed onto multi-walled carbon nanotubes synthesized on platinum electrode

摘要

Multi-walledcarbon nanotubes(MWCNTs)were synthesizedonplatinum plate electrodes by the chemical vapor deposition (CVD) method. From the results of X-ray photoelectron spectroscopy and voltammetric investigation, the iron nanoparticles used as a catalyst for the MWCNT synthesis were enclosed with MWCNTs. TheMWCNTs synthesized on the Pt plate (MWCNTs/Pt) electrodewere immediately immersed into solutions of d-fructose dehydrogenase (FDH) to immobilize the enzyme onto the MWCNTs/Pt electrode surfaces. After the FDH was immobilized onto the MWCNTs/Pt electrode, a well-defined catalytic oxidation current based on FDHwas observed fromca.-0.15V (versus Ag/AgCl/sat’d KCl), whichwas close to the redox potential of heme c as a prosthetic group of FDH. From an analysis of a plot of the catalytic current versus substrate, the calibration range for the fructose concentrationwas up to ca. 40mmoldm-3, and the apparent Michaelis–Menten constant was evaluated to be 11±1mmoldm-3.