dc.creator | Campos, Paula P. | |
dc.creator | Moraes, Marli L. | |
dc.creator | Volpati, Diogo | |
dc.creator | Miranda, Paulo Barbeitas | |
dc.creator | Oliveira Junior, Osvaldo Novais de | |
dc.creator | Ferreira, Marystela | |
dc.date.accessioned | 2017-06-13T15:25:38Z | |
dc.date.accessioned | 2018-07-04T17:13:20Z | |
dc.date.available | 2017-06-13T15:25:38Z | |
dc.date.available | 2018-07-04T17:13:20Z | |
dc.date.created | 2017-06-13T15:25:38Z | |
dc.date.issued | 2014-07 | |
dc.identifier | ACS Applied Materials and Interfaces,Washington, DC : American Chemical Society - ACS,v. 6, n.14, p. 11657-11664, July 2014 | |
dc.identifier | 1944-8244 | |
dc.identifier | http://www.producao.usp.br/handle/BDPI/51356 | |
dc.identifier | 10.1021/am5024463 | |
dc.identifier.uri | http://repositorioslatinoamericanos.uchile.cl/handle/2250/1646323 | |
dc.description.abstract | A direct, low-cost method to determine the concentration of lactose is an important goal with possible impact in various types of industry. In this study, a biosensor is reported that exploits the specific interaction between lactose and the enzyme β-galactosidase (β-Gal) normally employed to process lactose into glucose and galactose for lactose-intolerant people. The biosensor was made with β-Gal immobilized in layer-by-layer (LbL) films with the polyelectrolyte poly(ethylene imine) (PEI) and poly(vinyl sufonate) (PVS) on an indium tin oxide (ITO) electrode modified with a layer of Prussian Blue (PB). With an ITO/PB/(PEI/PVS)1(PEI/β-Gal)30 architecture, lactose could be determined with an amperometric method with sensitivity of 0.31 μA mmol-1 cm-2 and detection limit of 1.13 mmol L-1, which is sufficient for detecting lactose in milk and for clinical exams. Detection occurred via a cascade reaction involving glucose oxidase titrated as electrolytic solution in the electrochemical cell, while PB allowed for operation at 0.0 V versus saturated calomel electrode, thus avoiding effects from interfering species. Sum-frequency generation spectroscopy data for the interface between the LbL film and a buffer containing lactose indicated that β-Gal lost order, which is the first demonstration of structural effects induced by the molecular recognition interaction with lactose. | |
dc.language | eng | |
dc.publisher | American Chemical Society - ACS | |
dc.publisher | Washington, DC | |
dc.relation | ACS Applied Materials and Interfaces | |
dc.rights | Copyright American Chemical Society | |
dc.rights | restrictedAccess | |
dc.subject | lactose | |
dc.subject | amperometric detection | |
dc.subject | β-galactosidase | |
dc.subject | layer-by-layer | |
dc.subject | sum-frequency generation | |
dc.title | Amperometric detection of lactose using β‑Galactosidase immobilized in layer-by-layer films | |
dc.type | Artículos de revistas | |