title: Selective electrooxidation of uric acid in presence of ascorbic acid at a room temperature ionic liquid/nickel hexacyanoferarrate nanoparticles composite electrode.
abstract: A novel amperometric sensor for the determination of uric acid was fabricated using room temperature ionic liquid and nickel hexacyanoferrate nanoparticle composite which was immobilized on paraffin wax impregnated graphite electrode. The nickel hexacyanoferrate nanoparticle was characterized by UV-vis, X-ray diffraction and field emission scanning electron microscopy. The electrochemical behavior of the modified electrode was investigated in detail by electrochemical impedance spectroscopy, cyclic voltammetry and differential pulse voltammetry. Various experimental parameters influencing the electrochemical behavior of the modified electrode were optimized by varying the supporting electrolyte, scan rate and pH. The apparent electron transfer rate constant (K(s)) and charge transfer coefficient (α) of the modified electrode were found to be 1.358(± 0.02)cm/s and 0.65, respectively from cyclic voltammetry. The sensor exhibited an excellent electrocatalytic activity towards the oxidation of uric acid. The interference from ascorbic acid was easily overcome by coating the modified electrode with PEDOT layer. Under optimal condition, the determination range for uric acid is from 1.0 × 10(-6)M to 2.6 × 10(-3)M and the detection limit was 3.3 × 10(-7)M (3σ). The proposed method has been used for the determination of uric acid in human urine samples.
authors: Department of Analytical Chemistry, School of Chemical Sciences, University of Madras, Guindy Campus, Chennai 600 025, Tamil Nadu, India.
authors: R Suresh
authors: RS
authors: Babu
authors: P
authors: P
authors: Prabhu
authors: S Sriman
authors: SS
authors: Narayanan
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry*; D004566:Electrodes; D005295:Ferrocyanides / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology / Q000379:methods; D009532:Nickel / Q000737:chemistry*; D010084:Oxidation-Reduction; D013696:Temperature; D014527:Uric Acid / Q000737:chemistry*
chemical_list: D005295:Ferrocyanides; D052578:Ionic Liquids; C116383:ferrocyn; D014527:Uric Acid; D009532:Nickel; D001205:Ascorbic Acid