title: Graphitized carbon nanofiber-Pt nanoparticle hybrids as sensitive tool for preparation of screen printing biosensors. Detection of lactate in wines and ciders.
abstract: This work describes the fabrication of a new lactate biosensor. The strategy is based on the use of a novel hybrid nanomaterial for amperometric biosensors i.e. platinum nanoparticles (PtNps) supported on graphitized carbon nanofibers (PtNps/GCNF) prepared by chemical reduction of the Pt precursor at GCNF surfaces. The biosensors were constructed by covalent immobilization of lactate oxidase (LOx) onto screen printed carbon electrodes (SPCEs) modified with PtNps (PtNps/GCNF-SPCEs) using polyethyleneimine (PEI) and glutaraldehyde (GA). Experimental variables concerning both the biosensor design and the detection process were investigated for an optimal analytical performance. Lactate biosensors show good reproducibility (RSD 4.9%, n=10) and sensitivity (41,302±546) μA/Mcm(2), with a good limit of detection (6.9μM). Covalent immobilization of the enzyme allows the reuse of the biosensor for several measurements, converting them in a cheap alternative to the solid electrodes. The long-term stability of the biosensors was also evaluated. 90% of the signal was kept after 3months of storage at room temperature (RT), while 95% was retained after 18months at -20°C. These results demonstrate that the method provides sensitive electrochemical lactate biosensors where the stability of the enzymatic activity can be preserved for a long period of time in adequate storage conditions.
authors.affiliation: Sensors Unit, Materials Division, IK4-CIDETEC, Parque Tecnológico de San Sebastián, 20009 Donostia-San Sebastián, Spain. Electronic address: oloaiza@cidetec.es.
authors.forename: Oscar A
authors.initials: OA
authors.lastname: Loaiza
authors.affiliation: Sensors Unit, Materials Division, IK4-CIDETEC, Parque Tecnológico de San Sebastián, 20009 Donostia-San Sebastián, Spain.
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Lamas-Ardisana
authors.affiliation: Sensors Unit, Materials Division, IK4-CIDETEC, Parque Tecnológico de San Sebastián, 20009 Donostia-San Sebastián, Spain.
authors.forename: Larraitz
authors.initials: L
authors.lastname: Añorga
authors.affiliation: Sensors Unit, Materials Division, IK4-CIDETEC, Parque Tecnológico de San Sebastián, 20009 Donostia-San Sebastián, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Jubete
authors.affiliation: Sensors Unit, Materials Division, IK4-CIDETEC, Parque Tecnológico de San Sebastián, 20009 Donostia-San Sebastián, Spain.
authors.forename: Virginia
authors.initials: V
authors.lastname: Ruiz
authors.affiliation: Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, 00076 Aalto, Finland.
authors.forename: Maryam
authors.initials: M
authors.lastname: Borghei
authors.affiliation: Sensors Unit, Materials Division, IK4-CIDETEC, Parque Tecnológico de San Sebastián, 20009 Donostia-San Sebastián, Spain.
authors.forename: Germán
authors.initials: G
authors.lastname: Cabañero
authors.affiliation: Sensors Unit, Materials Division, IK4-CIDETEC, Parque Tecnológico de San Sebastián, 20009 Donostia-San Sebastián, Spain.
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Grande
mesh_terms: D001628:Beverages / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002244:Carbon / Q000737:chemistry; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D005504:Food Analysis / Q000295:instrumentation / Q000379:methods; D006108:Graphite / Q000737:chemistry; D019344:Lactic Acid / Q000032:analysis*; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000378:metabolism; D057139:Nanofibers / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry; D015203:Reproducibility of Results; D013696:Temperature; D014920:Wine / Q000032:analysis*
chemical_list: D004800:Enzymes, Immobilized; D019344:Lactic Acid; D010984:Platinum; D002244:Carbon; D006108:Graphite; D006899:Mixed Function Oxygenases; C021497:lactate 2-monooxygenase
keywords: Beverages; GCNF; Lactate biosensor; PtNps; Screen printing electrodes