Covalent Immobilization of Lactate Oxidase onto Zirconia Coated Silica Nanoparticles/Chitosan Hybrid Film for Amperometric Determination of Lactate
Kusum Dagar and Pundir CS*
Department of Biochemistry, Maharshi Dayanand University, Rohtak-124001, Haryana, India
- *Corresponding Author:
- Pundir CS
Department of Biochemistry
Maharshi Dayanand University
Rohtak-124001, Haryana, India
Tel: +91 9416492413
E-mail: [email protected]
Received Date: July 29, 2016; Accepted Date: November 10, 2016; Published Date: November 14, 2016
Citation: Dagar K, Pundir CS (2016) Covalent Immobilization of Lactate Oxidase onto Zirconia Coated Silica Nanoparticles/Chitosan Hybrid Film for Amperometric Determination of Lactate. Biochem Anal Biochem 5:301. doi: 10.4172/2161- 1009.1000301
Copyright: © 2016 Dagar K, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
An improved amperometric L-lactate biosensor was constructed based on covalent immobilization of lactate oxidase (LOx) onto zirconia coated silica nanoparticles ([email protected])/chitosan (CHIT) hybrid film electrodeposited on the surface of a gold electrode (AuE). The enzyme electrode was characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and electrochemical impedance spectroscopy (EIS), while [email protected] were synthesized by chemical reduction method and characterized by transmission electron microscopy (TEM), UV spectroscopy and X-ray diffraction (XRD). The biosensor showed an optimal response within 3s at pH 7.5 in 0.05M sodium phosphate buffer and 30°C, when operated at 20 mVs-1. The biosensor had a low detection limit of 0.2 nM with a wide working / linear range between 0.1 – 4000 μM. The biosensor was employed for measurement of L-lactic acid level in plasma of apparently healthy and diseased persons. Analytical recovery of added lactic acid (5.0 mM and 10.0 mM)) in plasma was 99% and 96.6% respectively. Within- and between-batch coefficients of variations were 1.79% and 2.89% respectively. There was a good correlation (R2=0.99) between plasma lactate values as measured by standard enzymatic spectrophotometric method and the present biosensor. The enzyme electrode was used 160 times over a period of 120 days, when stored dry at 4°C.