Immobilization of horseradish peroxidase on lysine-functionalized gum Arabic-coated FeO nanoparticles for cholesterol determination.

Background: Horseradish Peroxidase (HRP) is ranked as one of the most important industrial enzymes that is extensively used in industry. Cholesterol is routinely detected indirectly by cholesterol oxidase in the presence of O, liberating HO as a by-product. The HO content is determined through the HRP activity in the presence of a redox dye, producing a red colored quinoneimine which can be measured quantitatively.