title: Disposable amperometric biosensor based on lactate oxidase immobilised on platinum nanoparticle-decorated carbon nanofiber and poly(diallyldimethylammonium chloride) films.
abstract: A novel biosensor for lactate has been developed, using screen-printed carbon electrodes (SPCE) and lactate oxidase (LOx). The active surface of the electrodes was modified using a dispersion of platinum nanoparticle decorated carbon nanofibers (PtNp-CNF) in poly(diallyldimethylammonium) chloride (PDDA) solution. In this way, sensitive, disposable, low cost and reliable hydrogen peroxide sensors were obtained. The immobilisation of LOx on top of these PtNp-CNF-PDDA/SPCEs resulted in amperometric biosensors with high operational stability. The sensitivity of the optimised lactate biosensor was 36.8 (mA/Mcm(2)) with a linear range of 25-1500 µM. The limit of detection was 11 µM (S/N=3). Reproducibility, selectivity and storage stability were also evaluated. Additionally, the stability of the biosensor was also predicted by a model based on thermal degradation. Finally, lactate in sweat and blood samples was determined in a sport test using LOx/PtNp-CNF-PDDA/SPCEs and commercial biosensors respectively. Based on these data, the validity of the sweat lactate for the determination of the lactate threshold is discussed.
authors.affiliation: Sensors Unit, Materials Division, IK4-CIDETEC, Parque Tecnológico de San Sebastián, Paseo Miramón 196, 20009 Donostia-San Sebastián, Spain. Electronic address: plamas@cidetec.es.
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Lamas-Ardisana
authors.affiliation: Sensors Unit, Materials Division, IK4-CIDETEC, Parque Tecnológico de San Sebastián, Paseo Miramón 196, 20009 Donostia-San Sebastián, Spain.
authors.forename: Oscar A
authors.initials: OA
authors.lastname: Loaiza
authors.affiliation: Sensors Unit, Materials Division, IK4-CIDETEC, Parque Tecnológico de San Sebastián, Paseo Miramón 196, 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, Paseo Miramón 196, 20009 Donostia-San Sebastián, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Jubete
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, Paseo Miramón 196, 20009 Donostia-San Sebastián, Spain.
authors.forename: Virginia
authors.initials: V
authors.lastname: Ruiz
authors.affiliation: Sensors Unit, Materials Division, IK4-CIDETEC, Parque Tecnológico de San Sebastián, Paseo Miramón 196, 20009 Donostia-San Sebastián, Spain.
authors.forename: Estibalitz
authors.initials: E
authors.lastname: Ochoteco
authors.affiliation: Sensors Unit, Materials Division, IK4-CIDETEC, Parque Tecnológico de San Sebastián, Paseo Miramón 196, 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, Paseo Miramón 196, 20009 Donostia-San Sebastián, Spain.
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Grande
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D002244:Carbon / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D019344:Lactic Acid / Q000032:analysis* / Q000097:blood* / Q000378:metabolism; D057230:Limit of Detection; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000378:metabolism*; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D010376:Pediococcus / Q000201:enzymology; D010984:Platinum / Q000737:chemistry; D011095:Polyethylenes / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D015203:Reproducibility of Results; D013542:Sweat / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D019344:Lactic Acid; D010984:Platinum; D002244:Carbon; D006899:Mixed Function Oxygenases; C021497:lactate 2-monooxygenase
keywords: Carbon nanofiber; Lactate; Lactate oxidase; Platinum nanoparticle; Screen-printed electrode; Sweat