Magnetite Nanospheres as Carbon Paste Electrode Modifier for Xanthine Biosensor

• Published in: IOP conference series. Earth and environmental science 2018-11, Vol.187 (1), p.12013
• Main Authors: Ernis, G, Saprudin, D, Darusman, L K
• Format: Article
• Language: English
• Subjects: Benzoquinone; Biosensors; Carbon; Electrochemical analysis; Electrochemistry; Electrodes; Kinetics; Magnetite; Nanospheres; Scanning electron microscopy; X-ray diffraction; Xanthine oxidase
• ISSN: 1755-1307; 1755-1315; 1755-1315
• DOI: 10.1088/1755-1315/187/1/012013

Magnetite Nano spheres was prepared and used to fabricate a modified carbon paste electrode as xanthine biosensor and applied to determine inhibition kinetics of Syzygium polyanthum extract toward xanthine oxidase (XO). The magnetite Nano spheres was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Electrochemical behaviour of xanthine was investigated by immobilizing the XO on the surface of carbon paste electrode (CPE), modified magnetite Nano spheres-CPE (MCPE), and modified 2,3-dimethoxy-5-metil-1,4-benzoquinone (Q0)-CPE (QCPE) employing cyclic voltammetry (CV) technique. The result showed that the MCPE was the best electrode to determine the analytical performance under optimum condition, based on lower limit of detection (0.005 mM), wider linearity range (0.01-1 mM with R2 = 99.24%), and higher sensitivity (5.16 µM-1) than the two other electrodes (CPE and QCPE). The MCPE successfully improve the analytical performance on xanthine biosensor and to be applied for determining inhibition kinetics of S. polyanthum extract. Inhibition kinetics of the extract has caused increase of KM and VMAX (IMAX) constant. Based on the result, the type of inhibition kinetics was a competitive inhibition.