Laccase-Based Biosensor Encapsulated in a Galactomannan-Chitosan Composite for the Evaluation of Phenolic Compounds.

Imane Boubezari,Abdelhamid Errachid,François Bessueille,Gaëtan Raimondi,Anne Bonhomme,Ali Zazoua,Nicole Jaffrezic-Renault

doi:10.3390/bios10060070

Imane Boubezari, Abdelhamid Errachid + Show 5 more

Open Access

https://doi.org/10.3390/bios10060070

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Abstract

Galactomannan, a neutral polysaccharide, was extracted from carob seeds and characterized. It was used for the first time for the fabrication of a laccase-based biosensor by the encapsulation of laccase in a chitosan+galactomannan composite. The fabricated biosensor was characterized by FTIR, scanning electron microscopy and cyclic voltammetry. The pyrocatechol detection was obtained by cyclic voltammetry measurements, through the detection of o-quinone at −0.447 V. The laccase activity was well preserved in the chitosan+galactomannan composite and the sensitivity of detection of pyrocatechol in the 10−16 M–10−4 M range was very high. The voltammetric response of the biosensor was stable for more than two weeks. To estimate the antioxidant capacity of olive oil samples, it was shown that the obtained laccase-based biosensor is a valuable alternative to the colorimetric Folin–Ciocalteu method.

Highlights

Galactomannans are linear polysaccharides based on a -(l-4)-mannane backbone to which singleD-galactopyranosyl residues are attached via -(l-6) linkages
Galactomannans are industrially used in many domains: paper, textile, pharmaceutical, cosmetic and in food products as E410 additive
In this paper galactomannan was extracted from carob seeds

Summary

Introduction

D-galactopyranosyl residues are attached via -(l-6) linkages They can be extracted from different seeds (carob [1] and Trigonella foenum-graceum [2]). Their molecular composition depends on their origin, in particular the galactose content and the mannose/galactose ratio. Galactomannan was used in interpenetrating polymeric network with chitosan [3] and in polyvinyl alcohol [4] for the encapsulation of drugs in nanoparticles and their control release This polysaccharide was used for the encapsulation of enzymes in delivery systems of antimicrobial peptides and enzymes (protease and lipase), their own activity being well preserved [5]

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