title: Reagentless uric acid biosensor based on Ni microdiscs-loaded NiO thin film matrix.
abstract: The development of a noninvasive test for uric acid has been the holy grail of uric acid detection research over the last decade. In the present work, a novel matrix comprising of a NiO thin film (a biocompatible material) loaded with Ni microdiscs was prepared on an ITO-coated glass substrate (Ni/NiO/ITO) with the help of RF sputtering for the reagentless detection of uric acid. The bioelectrode was fabricated by immobilizing uricase using a physical adsorption technique on the surface of the Ni/NiO/ITO electrode. The prepared matrix was found to be efficient in sensing biological processes occurring on the surface of the bioelectrode (Ur/Ni/NiO/ITO) in the presence of the analyte (uric acid) to obtain an electronic output. The biosensor exhibits a high sensitivity (431.09 μA mM(-1)), low Km value (0.15 mM), high apparent enzyme activity (5.07 × 10(-2) units per cm(2)), high shelf life (20 weeks) and good selectivity for the detection of uric acid over a wide concentration range (0.05 mM to 1 mM) without any external mediator in the PBS buffer. The obtained results are encouraging for the realization of a reagentless uric acid biosensor with efficient sensing response characteristics.
authors.affiliation: Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India. vgupta@physics.du.ac.in.
authors.forename: Kashima
authors.initials: K
authors.lastname: Arora
authors.forename: Monika
authors.initials: M
authors.lastname: Tomar
authors.forename: Vinay
authors.initials: V
authors.lastname: Gupta
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000378:metabolism; D004867:Equipment Design; D006801:Humans; D057230:Limit of Detection; D009532:Nickel / Q000737:chemistry*; D017971:Tin Compounds / Q000737:chemistry; D014503:Urate Oxidase / Q000378:metabolism; D014527:Uric Acid / Q000097:blood* / Q000378:metabolism
chemical_list: D004800:Enzymes, Immobilized; D017971:Tin Compounds; D014527:Uric Acid; C109984:indium tin oxide; D009532:Nickel; C028007:nickel monoxide; D014503:Urate Oxidase