β-Cyclodextrin sensitized chemiluminescence of hemoglobin–hydrogen peroxide–carbonate and its analytical application Original Research Article

The weak chemiluminescence (CL) from the reaction of hemoglobin (Hb) with hydrogen peroxide in an aqueous carbonate solution was significantly enhanced in the presence of β-cyclodextrin (β-CD). The mechanism was discussed by examining CL emission spectrum and the effect of various free radical scavengers on CL emission intensity. The β-CD could form encapsulation complex with heme, which was dissociated from Hb in alkaline medium. The formed complex showed better catalytic activity than free heme thus resulting in an enhanced CL emission intensity. A flow injection CL method for the determination of Hb ranging from 2.0×10−9 to 1.0×10−5 g ml−1 was developed with β-CD as a sensitizer. The detection limit (3σ) for Hb was 1.2×10−9 g ml−1 (1.9×10−11 mol l−1) and the relative standard deviation (R.S.D.) for seven independent detections of 1.0×10−7 g ml−1 Hb was 2.4%. Since metal ions could not form complex with β-CD, this method showed a good selectivity. The proposed method was used for the determination of Hb in human blood and serum.