title: Monoamine oxidase B layer-by-layer film fabrication and characterization toward dopamine detection.
abstract: In this work nanostructured film composites of the monoamine oxidase B (MAO-B) enzyme, free or encapsulated in liposomes, were fabricated by the layer-by-layer (LbL) self-assembly technique, employing polyethylene imine (PEI) as polycation. Initially, the MAO-B enzyme was incorporated into liposomes in order to preserve its enzymatic structure ensuring their activity and catalytic stability. The LbL film growth was monitored by surface plasmon resonance (SPR) by gold resonance angle shift analysis after each bilayer deposition. Subsequently, the films were applied as amperometric biosensors for dopamine detection using Prussian Blue (PB) as the electron mediator. The biosensor fabricated by MAO-B incorporated into liposomes composed of DPPG:POPG in the ratio (1:4) (w/w) showed the best performance with a sensitivity of 0.86 (μA cm(-2))/(mmol L(-1)) and a detection limit of 0.33 mmol L(-1).
authors.affiliation: Universidade Federal de São Carlos, UFSCar, CCTS, Sorocaba, São Paulo, Brazil.
authors.forename: Celina Massumi
authors.initials: CM
authors.lastname: Miyazaki
authors.affiliation: Universidade Federal de São Carlos, UFSCar, CCTS, Sorocaba, São Paulo, Brazil.
authors.forename: Tamyris Paschoal
authors.initials: TP
authors.lastname: Pereira
authors.affiliation: Universidade Estadual de São Paulo - UNESP, Sorocaba, São Paulo, Brazil.
authors.forename: Daniela Branco Tavares
authors.initials: DB
authors.lastname: Mascagni
authors.affiliation: Universidade Federal de São Paulo, Unifesp, São José dos Campos, São Paulo, Brazil.
authors.forename: Marli Leite
authors.initials: ML
authors.lastname: de Moraes
authors.affiliation: Universidade Federal de São Carlos, UFSCar, CCTS, Sorocaba, São Paulo, Brazil. Electronic address: marystela@ufscar.br.
authors.forename: Marystela
authors.initials: M
authors.lastname: Ferreira
mesh_terms: D015374:Biosensing Techniques; D002942:Circular Dichroism; D004298:Dopamine / Q000032:analysis*; D055664:Electrochemical Techniques; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D005295:Ferrocyanides / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D008081:Liposomes / Q000737:chemistry; D008995:Monoamine Oxidase / Q000737:chemistry / Q000378:metabolism*; D049329:Nanostructures / Q000737:chemistry*; D011094:Polyethyleneimine / Q000737:chemistry; D020349:Surface Plasmon Resonance
chemical_list: D004800:Enzymes, Immobilized; D005295:Ferrocyanides; D008081:Liposomes; D011094:Polyethyleneimine; D008995:Monoamine Oxidase; C000170:ferric ferrocyanide; D004298:Dopamine
keywords: Amperometry; Dopamine detection; Layer-by-layer; Liposomes; Monoamine oxidase-B