A Comparative Study On NiO Nanocrystal Modified Graphite And Au Electrode Matrices As Immobilization Supports For Laccase Enzyme In Amperometric Biosensing For Catechol Detection
C. Sarika, M. S. Shivakumar, Lakhirupa Devi, K. Rekha, B. Narasimhamurthy, Sabu Thomas, Nandakumar Kalarikkal and I. C. Lekshmi
Volume 3, Issue 5, Page 304-311, Year 2018 | DOI: 10.5185/amp.2018/834
Keywords: Amperometric biosensor, laccase enzyme, NiO nanocrystals, clark type DO sensor, au electrode, carbon paste electrode, catechol detection.
Abstract: A comparative study of the electrochemical behaviours of two different electrode matrices used in the construction of amperometric laccase biosensors is reported here for catechol detection in water. The matrices considered are NiO nanocrystal (NC) modified graphite electrode (MCPE-NiO) and Au electrode of Clark type DO sensor. The laccase enzyme from Trametes versicolour was immobilized on electrode surfaces by co-crosslinking method using bovine serum albumin, a protein-based stabilizer, along with glutaraldehyde as the crosslinking agent. A comparison of the stability parameters of the electrode designs was carried out including sensitivity, calibration plots, analytical data and storage stability, and the biosensor performance was shown to be superior for MCPE-NiO-Lac compared to Au-Lac electrode. The NC modified system reached steady state within 6 seconds after the analyte contact and displayed a lower detection limit of 0.95 μM, while the Au electrode took 3 minutes to reach the same and had lower detection limit of 4 μM. Better reproducibility and longer linear response was also observed for MCPE-NiO system compared to the latter, all of which could be attributed to the microstructure of the electrode and the surface lattice arrangement in the embedded nanocrystals. Copyright © 2018 VBRI Press.