Promoting laccase sensing activity for catechol detection using LBL assemblies of chitosan/ionic liquid/phthalocyanine as immobilization surfaces

Abstract

The performance of electrochemical laccase-based biosensors can be improved by immobilizing the enzyme on composite Layer-by-Layer (LbL) supports in which materials with complementary functions are combined. LbL films are formed by layers combining an electrocatalytic material which favors electron transfer (sulfonated copper phthalocyanine, CuPc S(-) ), an ionic liquid which enhances the electrical conductivity of the layers (1-butyl-3-methylimidazolium tetrafluoroborate, IL (+) ) and a material able to promote enzyme immobilization (chitosan, CHI (+) ). Composite films with different structures have been demonstrated to be efficient electrocatalysts, producing an increase in the magnitude of the responses towards catechol. The most intense and reproducible electrocatalytic effect was observed when a layer of the CuPc S(-) was placed on top of a layer formed by a mixture of CHI (+) +IL (+) to obtain [CHI (+) +IL (+) |CuPc S(-) ] 2 films.Biosensors with laccase immobilized on the surface of the LbL layers [CHI (+) +IL (+) |CuPc S(-) ] 2 |Lac showed mediated electron transfer between the redox enzyme and the film and a reproducibility of device-to-device performance of 4.1%.The amperometric biosensor showed a sensitivity of 0.237 A•M −1 and a linear detection range from 2.4 μM to 26 μM for catechol. The excellent Limit of detection (LOD) of 8.96•10 -10 M (3•σ /m) is one order of magnitude lower than that obtained in similar studies. A Michaelis-Menten constant of 3.16 μM confirms excellent enzyme-substrate affinity.

Variables of the Analytical Electrochemical Data Acquisition for Boron Subphthalocyanines

“…Many porphyrinoids, like porphyrins, phthalocyanines, and other structurally similar macrocyclic compounds, have shown considerable promise as electrochemically active chemical sensors [1] given their rich π‐electron conjugated systems and chemical stability [2] . These sensors provide wide linear ranges, high sensitivity, and good limits/selectivity of detection [3] . Given the tunable redox activity and potentials of the porphyrins and phthalocyanines via a wide range of synthetic/structural modifications, [4] these macrocycles open doors to innumerous possible sensors and applications as active materials.…”

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

“…It is found to be 10 −16 M. The relative standard deviation for three biosensors was 3.5%. The obtained detection limit was in the low range of those of the previously published laccase-based biosensors fabricated through the encapsulation of laccase in chitosan, as presented in Table 1 [9][10][11][12][13][14][15][16][17][18].…”

Review—Enzymatic and Non-Enzymatic (bio)sensors Based on Phthalocyanines. A Minireview

“…Salvo-Comino et al 35 developed a laccase-based biosensor using the layer-by-layer (LbL) method. The composite LbL support of the biological material was obtained by combining three components; electrocatalytically material to promote the electron transfer (sulfonated copper phthalocyanine, CuPc S(−) ), an ionic liquid to increase the conductivity (1-butyl-3-methylimidazolium tetrafluoroborate, IL (+) ) and a material biocompatible for enzyme immobilization (chitosan, CHI (+) ).…”