Improving stability of biosensor based on covalent immobilization of horseradish peroxidase by γ-aminobutyric acid and application in detection of H2O2.

Improving stability of biosensor based on covalent immobilization of horseradish peroxidase by γ-aminobutyric acid and application in detection of H2O2. Int J Biol Macromol. 2019 Jun 15;: Authors: Feizabadi M, Soleymanpour A, Faridnouri H, Ajloo D Abstract A novel electrochemical biosensor for the determination of hydrogen peroxide (H2O2) has been fabricated through covalently immobilized horseradish peroxidase (HRP) on modified multi walled carbon nanotube (MWCNT) by γ-aminobutyric acid (GABA) on glassy carbon electrode. Using the electrochemical techniques, the electrochemical properties of the biosensor were specified. Cyclic voltammograms of the enzyme film at pH = 7.0 exhibited a pair of quasi-reversible redox peaks according to Fe(III/II) redox process of HRP. The biosensor exhibited good efficiency for finding H2O2 with a broad linear range from 2.0 × 10-7 M to 2.81 × 10-4 M and a detection limit of 0.13 μM. The surface coverage of active HRP, heterogeneous electron transfer rate constant and Michaelis-Menten constant of immobilized HRP were obtained 3.029 × 10-9 mol cm-2, 1.11 s-1, and 0.23 mM respectively. Similarly, the applicability of the suggested biosensor was examined by detecting H2O2 in human plasma samples and the average recovery was obtained as 100.50 ± 0.25. Moreover, the constructed biosensor presented a high stability, reproducibility and repeatability. Finally using doc...
Source: International Journal of Biological Macromolecules - Category: Biochemistry Authors: Tags: Int J Biol Macromol Source Type: research