Monoamine oxidase B layer-by-layer film fabrication and characterization toward dopamine detection

Publication year: 2015
Authors: Miyazaki C.M. 1, Pereira T.P. 1, Tavares Mascagni D.B. 2, de Moraes M.L. 3, Ferreira M. 1
Affiliations:

1 - Universidade Federal de São Carlos, UFSCar, CCTS, Sorocaba, São Paulo, Brazil
2
 - Universidade Estadual de São Paulo — UNESP, Sorocaba, São Paulo, Brazil
3 - Universidade Federal de São Paulo, Unifesp, São José dos Campos, São Paulo, Brazil

Published in: Materials Science and Engineering: C, 2015, Vol. 58, p. 310–315
doi: 10.1016/j.msec.2015.08.042

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.


MP-SPR keywords: amperometric biosensors development, deposition of free MAO-B enzyme, deposition of MAO-B enzyme incorporated into liposomes, layer-by-layer (LbL) assembly