title: Mixed hemi/ad-micelles coated magnetic nanoparticles for the entrapment of hemoglobin at the surface of a screen-printed carbon electrode and its direct electrochemistry and electrocatalysis.
abstract: An efficient procedure for the physical entrapment of proteins within a biocompatible matrix and their immobilization on electrode surfaces is of utmost importance in the fabrication of biosensors. In this work, the magnetic entrapment of hemoglobin (Hb) at the surface of a screen-printed carbon electrode (SPCE), through mixed hemi/ad-micelles (MHAM) array of positively charged surfactant supported iron oxide magnetic nanoparticles (Mag-NPs), is reported. The Hb/MHAM@Mag-NPs biocomposite is captured at SPCE by a super magnet (Hb/MHAM@Mag-NPs/SPCE). To gain insight in the configuration of the mixed hemi/ad-micelles of CTAB at Mag-NPs, zeta-potential measurements were performed. The entrapment of Hb at MHAM@Mag-NPs was confirmed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Fourier transform infrared spectroscopy (FT-IR). Direct electron transfer of the Hb intercalated into the composite film showed a pair of well-defined quasi-reversible redox peak at formal potential of -0.255 V vs. Ag/AgCl corresponding to heme Fe(III)/Fe(II) redox couple. It shows that the MHAM@Mag-NPs composite could increase the adsorption ability for Hb, thus provides a facile direct electron transfer between the Hb and the substrate. The proposed biosensor showed excellent electrocatalytic activity to the H2O2 reduction in the wide concentration range from 5.0 to 300.0 µM obtained by amperometric measurement. The Michaelis-Menten constant (Km) value of Hb at the modified electrode is 55.4 µM, showing its high affinity. Magnetic entrapment offers a promising design for fast, convenient and effective immobilization of protein within a few minutes for determination of the target molecule in low sample volume at disposable cost-effective SPCE.
authors.affiliation: Electroanalytical Chemistry Laboratory, Department of Analytical Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran; AXES, Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
authors.forename: Mohaddeseh
authors.initials: M
authors.lastname: Amiri-Aref
authors.affiliation: Electroanalytical Chemistry Laboratory, Department of Analytical Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran. Electronic address: j.raoof@umz.ac.ir.
authors.forename: Jahan Bakhsh
authors.initials: JB
authors.lastname: Raoof
authors.affiliation: Department Pharmaceutics, Campus Drie Eiken, University of Antwerp, 2020 Antwerp, Belgium.
authors.forename: Filip
authors.initials: F
authors.lastname: Kiekens
authors.affiliation: AXES, Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium. Electronic address: karolien.dewael@uantwerpen.be.
authors.forename: Karolien
authors.initials: K
authors.lastname: De Wael
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry; D002384:Catalysis; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis; D003217:Conductometry / Q000295:instrumentation*; D004209:Disposable Equipment; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006454:Hemoglobins / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis* / Q000737:chemistry; D018189:Immunomagnetic Separation / Q000295:instrumentation*; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D066330:Printing, Three-Dimensional
chemical_list: D020099:Coated Materials, Biocompatible; D006454:Hemoglobins; D058185:Magnetite Nanoparticles; D002244:Carbon; D006861:Hydrogen Peroxide
keywords: Biosensor; Direct electrochemistry; Hemoglobin; Magnetic entrapment; Mixed hemi/ad-micelles; Zeta potential