title: A novel biamperometric biosensor for urinary oxalate determination using flow-injection analysis.
abstract: A biosensor for determination of oxalate concentration in urine has been developed by immobilisation of oxalate oxidase and peroxidase on the surface of an interdigitated gold electrode. Enzyme immobilisation was performed using BSA and glutaraldehyde. Biamperometric measurements were made in flow conditions both in aqueous oxalate solutions (tested concentration range between 50 microM and 10 mM) and in real urine samples (tested measuring range between 5 and 100 microM). Optimal working conditions were examined for flow-injection analysis, and good correlation was achieved between added oxalate quantity and the one measured by biosensor in urine matrix (R(2)=0.9983). The influence of some interferences (ascorbic acid, uric acid, paracetamol, acetylsalicylic acid) was also studied using biamperometric measurement mode.
authors.affiliation: Department of General and Inorganic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, HR-10000 Zagreb, Croatia. stjepan.milardovic@fkit.hr
authors.forename: Stjepan
authors.initials: S
authors.lastname: Milardović
authors.forename: Irena
authors.initials: I
authors.lastname: Kereković
authors.forename: Marijana
authors.initials: M
authors.lastname: Nodilo
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D002138:Calibration; D003486:Cyanides / Q000652:urine; D017022:Flow Injection Analysis / Q000295:instrumentation* / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007201:Indicator Dilution Techniques; D010070:Oxalates / Q000652:urine*
chemical_list: D003486:Cyanides; D010070:Oxalates