Optical biosensor for catechol determination based on laccase‐immobilized anionic polyamide 6 microparticles

Abstract

This work presents the preparation, optimization, and testing of an enzymebased optical biosensor for catechol determination. The sensing area is attached to a glass support and contains: anionic polyamide 6 (PA6) porous microparticles supporting laccase from Trametes Versicolor, embedded in a Pebax ® MH1657 polymer binder that contains the optical indicator dye 3-methyl-2-benzothiazolinone hydrazone (MBTH), responsible for the optical transduction. The catechol analyte, after its enzymatic oxidation, forms o-benzoquinone that can be detected by oxidative coupling with MBTH giving rise to a colored product. The latter can be quantified measuring the UV/VIS absorbance at 500 nm. The PA6 microparticles performed as useful laccase carriers reaching high immobilization yields of up to 99.8% and preserving the enzyme catalytic activity. This permitted the preparation of a new biosensor presenting a detection limit of 11 μM and responding linearly to up to 118 μM of catechol. Biosensor applicability was tested in spiked natural water samples from river and spring. The recovery rates observed were in the range of 97-108% that proves the good accuracy of the proposed biosensor.

Synthesis and properties of neat, hybrid, and copolymeric polyamide 12 microparticles and composites on their basis

“…The rest of the MP samples did not display resolved SAXS peaks. Such phenomenon was observed and studied previously with PA6 MP 19 . There, the absence of a Bragg peak was explained with the extensive micron‐sized porosity of the polyamide MP that makes negligible the density gradient between the crystalline and amorphous phases.…”

“…This process permitted the preparation of polyamide MP based on PA6, carrying elevated amounts of fillers, i.e., metal‐, ceramic‐, carbon allotrope or mixed payloads, as well as other polymer particles. Further investigations revealed that these hybrid MP can be used directly as supports for enzymes in biosensors or biocatalysts 19,20 or they can be transformed by melt processing into PA6‐based hybrids or laminate composites 21,22 . The procedure of ref.…”

Advanced Optical Sensing of Phenolic Compounds for Environmental Applications

“…Very recently, Cano-Raya et al proposed a new laccase-based optical biosensor for catechol concentration determination [63]. Laccase from Trametes Versicolor is attached to anionic polyamide 6 (PA6) porous microparticles placed in a Pebax MH1657 polymer binder that includes MBTH that can produce a colored product when it interacts with the o-benzoquinone produced by the enzymatic reaction of catechol.…”

D‐A‐D type functional conducting polymer: Development of its electrochromic properties and laccase biosensor

“…Their quite simple manufacturing procedure are highly fast and sensitive properties makes them very useful for catechol detection 7 . One of these biosensor compounds is the laccase enzyme, (benzenediol: oxygen oxidoreductases, EC 1.10.3.2), known as a multi‐copper oxidase and is commonly used in the construction of various biosensors 8–11 . To make enzyme molecules on the electrode surface more stable, efficient materials and immobilization strategies are necessary.…”