title: Sensitive nitrate determination in water and meat samples by amperometric biosensor.
abstract: This study describes a novel biosensor method for specific determination of nitrate in food and water samples by using nitrate reductase (NR) (EC 1.9.6.1) biosensor based on the detection of oxidation peak current of redox mediator, methyl viologen, related to nitrate concentration. The method was shown to be selective and sensitive to determine the nitrate levels of water samples and processed meat samples. Immobilization procedure and also working conditions of the biosensor were optimized. Dynamic range attained with this method was established as (5.0-90.0 x 10(-9) M) for nitrate concentration with a 10 s response time. Limit of detection (LOD) and quantification (LOQ) of the biosensor were calculated as 2.2 x 10(-9) M and 5.79 x 10(-9) M, respectively. Reproducibility experiments was established on repetitive measurements by using a freshly prepared biosensor for avoiding the memory effect. The RSD was calculated as 1.22% at a nitrate concentration of 4.7 x 10(-8) M (n = 7).
authors.affiliation: Department of Biochemistry, Faculty of Science, Ege University, Bornova-Izmir, Turkey.
authors.forename: Erhan
authors.initials: E
authors.lastname: Dinçkaya
authors.forename: Erol
authors.initials: E
authors.lastname: Akyilmaz
authors.forename: M Kemal
authors.initials: MK
authors.lastname: Sezgintürk
authors.forename: F Nil
authors.initials: FN
authors.lastname: Ertaş
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005504:Food Analysis / Q000295:instrumentation*; D005506:Food Contamination / Q000032:analysis*; D008460:Meat / Q000032:analysis*; D009566:Nitrates / Q000032:analysis*; D012680:Sensitivity and Specificity; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D009566:Nitrates; D014874:Water Pollutants, Chemical; D014867:Water