Removal of proteinaceous soils using hydroxyl radicals generated by the electrolysis of hydrogen peroxide

We have developed here for the first time a novel method to generate hydroxyl radicals, •OH, by applying slightly negative electric potentials (-0.2 - 0.8 V vs Ag/AgCl) to the surface of a metal (or metal oxide) that is in contact with hydrogen peroxide solution containing a supporting electrolyte. Namely, •OH radicals were generated at the surface by the electrolysis of hydrogen peroxide according to the equation, H₂O₂ + e^- → •OH + OH^-. This method was used to clean a stainless steel fouled with a model protein, β-lactoglobulin. The •OHs generated at the surface were effective in removing β-lactoglobulin that had been irreversibly adsorbed, by several minutes of treatment at room temperature (22 ± 23°C). The removal rates measured for various concentrations of H₂O₂ and supporting electrolyte and different potentials were determined exclusively by the electric current.