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

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.

Recent Advances in the Development of Oxidoreductase-Based Biosensors for Detection of Phenolic Antioxidants in Food and Beverages

“…Chitosan is the most widely used polysaccharide for enzyme encapsulation. Recently, a laccase-based biosensor was prepared by encapsulating laccase in a galactomannan-chitosan polymer composite onto a gold electrode for analysis of phenolic compounds in olive oil samples . The constructed biosensor could detect as little as 10 –10 μM of pyrocatechol.…”

Chitosan-Based Nanocomposites for Biological Applications

“…Laccase-Based Biosensor Encapsulated in a Galactomannan-Chitosan Composite [148] Ti 3 C 2 T X MXene/Chitosan Nanocomposite-Based Amperometric Biosensor [149] Glucose oxidase-chitosan immobilized paper biosensor [150] Diffraction-based chitosan leaky waveguide (LW) biosensors [151] Carboxymethyl chitosan assembled piezoelectric biosensor [152] Au nanoparticles/MoS 2 nanosheets-Chitosan modified screen-printed electrode as chlorpyrifos biosensor [153] Temperature-sensitive poly(N-isopropylacrylamide)-chitosan hydrogel for fluorescence sensors [154] Table 1.…”

Biosensing Dopamine and L-Epinephrine with Laccase (Trametes pubescens) Immobilized on a Gold Modified Electrode

“…The resulting current rises proportionally to the mediator concentration, because the latter donates one electron to the T1 laccase active site; electricity flows further through internal pathways to the tri-nuclear cluster where the ORR takes place, this way facilitating the electron exchange with the electrode. Mediated oxygen reduction has been actively explored in an electroanalytical aspect as well, since diverse biosensors for phenols [ 10 , 11 , 12 , 13 , 14 , 15 ], including Bisphenol A [ 16 ], catechols [ 17 , 18 ], tartrazine [ 19 ] and hydrocinnamic acids [ 20 ], have been reported recently. Moreover, the sensitivity of the determination depends not only on the enzyme immobilization strategy, but also on the affinity of laccase to the analyte.…”

“…Moreover, the sensitivity of the determination depends not only on the enzyme immobilization strategy, but also on the affinity of laccase to the analyte. In general, the analyte that is oxidized entirely biocatalytically when interfacing the immobilized enzyme, is further reduced electrochemically at the electrode, poised at some reductive potential—usually −0.1 V to −0.5 V (vs. Ag|AgCl) [ 11 ].…”