Zinc oxide nanoparticles/glucose oxidase photoelectrochemical system for the fabrication of biosensor

• Published in: Journal of colloid and interface science 2009-06, Vol.334 (2), p.183-187
• Main Authors: Ren, Xiangling, Chen, Dong, Meng, Xianwei, Tang, Fangqiong, Hou, Xianquan, Han, Dong, Zhang, Lin
• Format: Article
• Language: English
• Subjects: Aspergillus niger - enzymology; Biosensing Techniques - economics; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biosensor; Catalysis; Chemistry; Circular Dichroism; Colloidal state and disperse state; Electrochemistry; Exact sciences and technology; General and physical chemistry; Glucose - analysis; Glucose - metabolism; Glucose oxidase; Glucose Oxidase - chemistry; Glucose Oxidase - metabolism; Hydrogen-Ion Concentration; Nanoparticles - chemistry; Nanoparticles - ultrastructure; Photochemistry; Photoelectrochemical system; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Protein Conformation; Radiation; Sensitivity and Specificity; Spectrophotometry; Surface physical chemistry; Temperature; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Ultraviolet Rays; Zinc Oxide - chemistry; Zinc oxide nanoparticles
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2009.02.043

ZnO nanoparticles could significantly enhance the current response of the enzyme electrodes and the current response of these modified electrodes could be further increased under illumination. Nanosized semiconductor crystals can increase efficiency of photochemical reactions and greatly improve the catalytic activity of enzymes to generate novel photoelectrochemical systems. In this work, glucose oxidase (GOx)/zinc oxide (ZnO) is selected as a model system to assess the photovoltaic effect of semiconductor nanoparticles on the enzyme electrode. UV-spectrum and circular dichroism (CD) results show that the structure of GOx is preserved after conjugation with ZnO nanoparticles. The current response of the enzyme electrode containing ZnO nanoparticles increases from 0.82 to 21 μA cm −2 in the solution of 10 mM β- d-glucose. Furthermore, after irradiating the enzyme electrode with UV light for 2 h, the current response can be increased nearly 30% and the detection limit can be lowered about two orders compared with the catalytic reactions in the dark, which indicate that a technique to fabricate a novel photocontrolled enzyme-based biosensor may be developed.