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Amperometric detection of lactose using -galactosidase immobilized in layer-by-layer films

Campos, Paula P. ; Moraes, Marli L. ; Volpati, Diogo LU ; Miranda, Paulo B. ; Oliveira, Osvaldo N. and Ferreira, Marystela (2014) In ACS Applied Materials and Interfaces 6(14). p.11657-11664
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... (More)

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 A 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.

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author
; ; ; ; and
publishing date
type
Contribution to journal
publication status
published
keywords
amperometric detection, lactose, layer-by-layer, sum-frequency generation, β-galactosidase
in
ACS Applied Materials and Interfaces
volume
6
issue
14
pages
8 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • scopus:84905046234
  • pmid:24991705
ISSN
1944-8244
DOI
10.1021/am5024463
language
English
LU publication?
no
id
559ad624-6f3e-4eb9-9433-ae169f2f3826
date added to LUP
2019-05-17 14:34:21
date last changed
2025-05-01 23:40:14
@article{559ad624-6f3e-4eb9-9433-ae169f2f3826,
  abstract     = {{<p>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)<sub>1</sub>(PEI/β-Gal)<sub>30</sub> architecture, lactose could be determined with an amperometric method with sensitivity of 0.31 A mmol<sup>-1</sup> cm<sup>-2</sup> and detection limit of 1.13 mmol L <sup>-1</sup>, 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.</p>}},
  author       = {{Campos, Paula P. and Moraes, Marli L. and Volpati, Diogo and Miranda, Paulo B. and Oliveira, Osvaldo N. and Ferreira, Marystela}},
  issn         = {{1944-8244}},
  keywords     = {{amperometric detection; lactose; layer-by-layer; sum-frequency generation; β-galactosidase}},
  language     = {{eng}},
  month        = {{07}},
  number       = {{14}},
  pages        = {{11657--11664}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{ACS Applied Materials and Interfaces}},
  title        = {{Amperometric detection of lactose using -galactosidase immobilized in layer-by-layer films}},
  url          = {{http://dx.doi.org/10.1021/am5024463}},
  doi          = {{10.1021/am5024463}},
  volume       = {{6}},
  year         = {{2014}},
}