“…The response of the CDH modified SPCEs as a function of pH showed that the response current for both immobilised enzymes attained a maximum at pH 4.5 (citrate buffer containing 0.1 M KCl), that was used in the following experiments. In order to minimise enzyme inactivation, possible interferences from other components, which might be present in the sample (e.g., ascorbic, uric acids) [29][30][31][32] but, on the other hand, still be able to detect the analyte with a high sensitivity a potential of 100 mV vs. pseudo Ag|AgCl (which is formed on the surface of the reference electrode due to the presence of KCl in the working buffer) was chosen for all further experiments. A flow rate of 0.57 mL min −1 provided a good combination of both high and rapid analytical response for the chosen system and was used for further experiments.…”