title: Amperometric cytochrome c3-based biosensor for chromate determination.
abstract: The chromate reductase activity of cytochrome c(3) (Cyt c(3), M(r) 13000), isolated from the sulfate-reducing bacterium Desulfomicrobium norvegicum, was used to develop an amperometric biosensor to measure chromate (CrO(4)(2-)) bioavailability. The performance of various biosensor configurations for qualitative and quantitative determination of Cr(VI) was studied. Biosensor properties depend on the technique used to immobilize the enzyme on the electrode (glassy carbon electrode). Immobilization of Cyt c(3) by entrapment in poly 3,4-ethylenedioxythiophene films denatured the enzyme, while application of an adsorption technique did not affect enzyme activity but the detection range was limited. The best results were obtained with dialysis membranes, which allowed the determination of Cr(VI) from 0.20 to 6.84 mg l(-1) (3.85-132 microM) with a sensitivity of 35 nA mg(-1) l (1.82 nA microM(-1)). No interference was observed with As(V), As(III) and Fe(III). Only a small amount of Cyt c(3) (372 ng of protein) was needed for this biosensor.
authors: BRGM, Service Environnement Industriel et Procédés Innovants, Unité Biotechnologies, 3 Avenue Claude Guillemin, BP 6009, 45060 Orleans Cedex 02, France.
authors: Caroline
authors: C
authors: Michel
authors: Fabienne
authors: F
authors: Battaglia-Brunet
authors: Canh Tran
authors: CT
authors: Minh
authors: Mireille
authors: M
authors: Bruschi
authors: Ioannis
authors: I
authors: Ignatiadis
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002840:Chromates / Q000032:analysis* / Q000737:chemistry*; D003574:Cytochrome c Group / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D002840:Chromates; D003574:Cytochrome c Group; D004785:Environmental Pollutants; D004800:Enzymes, Immobilized; C017165:cytochrome c(3)