title: An amperometric biosensor based on hemoglobin immobilized in poly(epsilon-caprolactone) film and its application.
abstract: In this study, poly(epsilon-caprolactone) (PCL) was synthesized using the epsilon-caprolactone (CL) monomer ring-opening polymerization. We demonstrated that the hemoglobin (Hb) entrapped in PCL film could retain its original conformation by FT-IR spectra. A pair of well-defined redox peaks with a formal potential (E0') of about -0.38V (vs. SCE) in a pH 7.0 phosphate buffer solution was obtained at the Hb-PCL film modified GC electrode. The dependence of E(0') on the pH of the buffer solution indicated that the conversion of heme Fe(III)/Fe(II) was a reaction of one electron coupled to one proton. The apparent heterogeneous electron transfer rate constants (ks) of Hb confined to PCL was valuated as (18.7+/-0.8)s(-1) according to Laviron's equation. The surface concentration (Gamma*) of the electroactive Hb in the PCL film was estimated to be (7.27+/-0.57)x10(-11)molcm(-2). The Hb-PCL film modified electrode was shown to be an excellent amperometric sensor for the detection of hydrogen peroxide. The linear range is from 2 to 30microM with a detection limit of 6.07x10(-6)M. The sensor was effectively testified by the determination of the hydrogen peroxide in eyedrops as real samples.
authors.affiliation: LTCS and Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871, China.
authors.forename: W
authors.initials: W
authors.lastname: Zheng
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: Y F
authors.initials: YF
authors.lastname: Zheng
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006454:Hemoglobins / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis* / Q000737:chemistry; D008567:Membranes, Artificial; D011091:Polyesters / Q000737:chemistry*; D011485:Protein Binding; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D006454:Hemoglobins; D008567:Membranes, Artificial; D011091:Polyesters; C016240:polycaprolactone; D006861:Hydrogen Peroxide