Observation of the complex formation between Cu(II) and protein by capillary electrophoretic system incorporating an UV/CL dual detector

We investigated the complex formation between Cu(II) and human serum albumin (HSA) through a biuret reaction by use of capillary electrophoretic system incorporating an ultra-violet absorption (UV) and chemiluminescence (CL) dual detector. Cu(II)–tartrate complex and Cu(II)–human serum albumin complex were detected by UV detection (282 nm) with on-capillary, followed by CL detection (luminol–hydrogen peroxide CL reaction) with end-capillary. We examined the effects of the reaction time and temperature on the UV and CL responses. On the basis of the obtained results we considered the Cu(II)–human serum albumin complex formation processes and its catalytic activity for the CL reaction. The system easily, rapidly, and simultaneously produced useful information concerning the complex formation of Cu(II) and human serum albumin due to the presence of the both detectors.