title: Disposable biosensor based on cathodic electrochemiluminescence of tris(2,2-bipyridine)ruthenium(II) for uric acid determination.
abstract: A new method for uric acid (UA) determination based on the quenching of the cathodic ECL of the tris(2,2-bipyridine)ruthenium(II)-uricase system is described. The biosensor is based on a double-layer design containing first tris(2,2-bipyridine)ruthenium(II) (Ru(bpy)3(2+)) electrochemically immobilized on graphite screen-printed cells and uricase in chitosan as a second layer. The uric acid biosensing is based on the ECL quenching produced by uric acid over the cathodic ECL caused by immobilized Ru(bpy)3(2+) in the presence of uricase. The use of a -1.1 V pulse for 1s with a dwelling time of 10s makes it possible to estimate the initial enzymatic rate, which is used as the analytical signal. The Stern-Volmer type calibration function shows a dynamic range from 1.0×10(-5) to 1.0×10(-3)M with a limit of detection of 3.1×10(-6)M and an accuracy of 13.6% (1.0×10(-4)M, n=5) as relative standard deviation. Satisfactory results were obtained for urine samples, creating an affordable alternative for uric acid determination.
authors.affiliation: ECsens, Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, University of Granada, E-18071 Granada, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Ballesta-Claver
authors.forename: R
authors.initials: R
authors.lastname: Rodríguez-Gómez
authors.forename: L F
authors.initials: LF
authors.lastname: Capitán-Vallvey
mesh_terms: D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives* / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation*; D056831:Coordination Complexes; D055664:Electrochemical Techniques; D004566:Electrodes; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D008163:Luminescent Measurements; D014527:Uric Acid / Q000032:analysis* / Q000652:urine; D017975:Ruthenium Compounds
chemical_list: D015082:2,2'-Dipyridyl; D056831:Coordination Complexes; D006861:Hydrogen Peroxide; D014527:Uric Acid; C547232:tris(2,2-bipyridine)-ruthenium(II); D017975:Ruthenium Compounds