Chronoamperometric stripping analysis following biocatalytic preconcentration

Electrodes containing glucose oxidase or xanthine oxidase adsorbed on modified glassy carbon electrodes or on conductive complexes, accumulate charge in the presence of substrates, the discharge of which gives the chronoamperometric stripping current. This current is 15 times higher than the stationary current after preconcentration for 8 min. A ten-fold increase in sensitivity of the determination of glucose or hypoxanthine is observed. The stripping current of electrodes based on cytochrome b₂ adsorbed on a graphite electrode is 25 times higher than the stationary current. The electrode is useful for lactate determinations for more than 7 days.