An electrochemical biosensor for rapid detection of bovine serum albumin damage induced by hydroxyl radicals in room temperature ionic liquid

Oxidative protein damage has been widely implicated in carcinogenesis and other disorders. Sensitive and reliable detection of protein oxidative damage remains a significant challenge. Reported herein is a novel electrochemical biosensor for direct detection of bovine serum albumin (BSA) oxidative damage in 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]). Oxidation of BSA immobilized on the electrode was induced by hydroxyl radical produced from Fenton reaction. An electroactive indicator, Tris(2,2′-bipyridyl)cobalt(III)perchlorate, was employed in the detection. The oxidative peak current of Co(bpy)33+ decreased with the incubation time of BSA film in Fenton reagents. Electrochemical impedance spectroscopy was used to study the interface properties of the protein modified electrode surface. More dramatic damage in [BMIM][PF6] compared with that in an aqueous solvent media confirmed that [BMIM][PF6] was suitable medium for the electrochemical detection of BSA damage. The influences of the incubation time, the concentrations of Fenton reagents and antioxidants on BSA damage were obtained. The method is promising for a rapid and sensitive detection of protein damage.