Screen-Printed Silver/Silver Chloride Electrodes Inhibit Alcohol Oxidase Activity

Silver/silver chloride (Ag/AgCl) is ubiquitous in the field of electrochemical biosensing due to its suitability as a reference electrode material. However, we recently discovered that screen-printed Ag/AgCl ink has a detrimental effect on Alcohol Oxidase enzyme stability. We performed an optical absorbance assay to isolate the interaction of enzyme and electrode to discover a surprisingly strong inhibition effect. The halftime of enzymatic activity was reduced from nearly 1 week in buffer to 10 h in the presence of the Ag/AgCl electrode. We expect this discovery to have broad implications on enzymatic biosensors that use Ag/AgCl as reference electrode material.