title: Formaldehyde-sensitive sensor based on recombinant formaldehyde dehydrogenase using capacitance versus voltage measurements.
abstract: A new formaldehyde-selective biosensor was constructed using NAD(+)- and glutathione-dependent recombinant formaldehyde dehydrogenase as a bio-recognition element immobilised on the surface of Si/SiO(2)/Si(3)N(4) structure. Sensor's response to formaldehyde was evaluated by capacitance measurements. The calibration curves obtained for formaldehyde concentration range from 10 microM to 20mM showed a broad linear response with a sensitivity of 31 mV/decade and a detection limit about 10 microM. It has been shown that the output signal decreases with the increase of borate buffer concentration and the best sensitivity is observed in 2.5mM borate buffer, pH 8.40. The response of the created formaldehyde-sensitive biosensor has also been examined in 2.5mM Tris-HCl buffer, and the shift to the positive bias of the C(V) curves along with the potential axis has been observed, but the sensitivity of the biosensor in this buffer is decreased dramatically to the value of 2.4 mV/decade.
authors.affiliation: Institut Supérieur des Sciences, Appliquées et de Technologies de Sousse, Cité Taffela , Ibn Khaldoun, 4003, Sousse Tunisia. mounirbenali@yahoo.com
authors.forename: M
authors.initials: M
authors.lastname: Ben Ali
authors.forename: M
authors.initials: M
authors.lastname: Gonchar
authors.forename: G
authors.initials: G
authors.lastname: Gayda
authors.forename: S
authors.initials: S
authors.lastname: Paryzhak
authors.forename: M A
authors.initials: MA
authors.lastname: Maaref
authors.forename: N
authors.initials: N
authors.lastname: Jaffrezic-Renault
authors.forename: Y
authors.initials: Y
authors.lastname: Korpan
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000378:metabolism*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D025802:Electric Capacitance; D005557:Formaldehyde / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D011994:Recombinant Proteins / Q000378:metabolism; D012666:Semiconductors; D014159:Transducers
chemical_list: D011994:Recombinant Proteins; D005557:Formaldehyde; C020145:formaldehyde dehydrogenase (glutathione); D000445:Aldehyde Oxidoreductases