These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Self-assembled films of hemoglobin/laponite/chitosan: application for the direct electrochemistry and catalysis to hydrogen peroxide.
    Author: Shan D, Han E, Xue H, Cosnier S.
    Journal: Biomacromolecules; 2007 Oct; 8(10):3041-6. PubMed ID: 17824641.
    Abstract:
    A highly stable biological film was formed on the functional glassy carbon electrode (GCE) via step-by-step self-assembly of chitosan (CHT), laponite, and hemoglobin (Hb). Cyclic voltammetry (CV) of the Hb/laponite/CHT/GCE showed a pair of stable and quasi-reversible peaks for the Hb-Fe(III)/Fe(II) redox couple at about -0.035 V versus a saturated calomel electrode in pH 6.0 phosphate buffer at a scan rate of 0.1 V s(-1). The electrochemical reaction of Hb entrapped on the laponite/CHT self-assembled film exhibited a surface-controlled electrode process. The formal potential of the Hb-heme-Fe(III)/Fe(II) couple varied linearly with the increase of pH over the range of 3.0-8.0 with a slope of -63 mV pH(-1), which implied that an electron transfer was accompanied by single-proton transfer in the electrochemical reaction. The position of the Soret absorption band of this self-assembled Hb/laponite/CHT film suggested that the entrapped Hb kept its secondary structure similar to its native state. The self-assembled film showed excellent long-term stability, the CV peak potentials kept in the same positions, and the cathodic peak currents retained 90% of their values after 60 days. The film was used as a biological catalyst to catalyze the reduction of hydrogen peroxide. The electrocatalytic response showed a linear dependence on the H2O2 concentration ranging widely from 6.2 x 10(-6) to 2.55 x 10(-3) M with a detection limit of 6.2 x 10(-6) M at 3 sigma.
    [Abstract] [Full Text] [Related] [New Search]