Laccase biosensors based on different enzyme immobilization strategies for phenolic compounds determination

Abstract

Different enzyme immobilization approaches of Trametes versicolor laccase (TvL)onto gold surfaces and their influence on the performance of the final bioanalytical platforms are described. The laccase immobilization methods include: i) direct adsorption onto gold electrodes (TvL/Au), ii) covalent attachment to a gold surface modified with a bifunctional reagent, 3,3'-Dithiodipropionic acid di (N-succinimidyl ester) (DTSP), and iii) integration of the enzyme into a sol-gel 3D polymeric network derived from (3-mercaptopropyl)-trimethoxysilane (MPTS) previously formed onto a gold surface (TvL/MPTS/Au). The characterization and applicability of these biosensors are described. Characterization is performed in aqueous acetate buffer solutions using atomic force microscopy (AFM), providing valuable information concerning morphological data at the nanoscale level.The response of the three biosensing platforms developed, TvL/Au, TvL/DTSP/Au and TvL/MPTS/Au, is evaluated in the presence of hydroquinone (HQ), used as a phenolic enzymatic substrate. All systems exhibit a clear electrocatalytic activity and HQ can be amperometrically determined at -0.10 V versus Ag/AgCl. However, the performance of biosensors -evaluated in terms of sensitivity, detection limit, linear 2 response range, reproducibility and stability-depends clearly on the enzyme immobilization strategy, which allows establishing its influence on the enzyme catalytic activity.

Sensitive bi-enzymatic biosensor based on polyphenoloxidases–gold nanoparticles–chitosan hybrid film–graphene doped carbon paste electrode for carbamates detection

“…2A) achieved a maximum value at pH 5.0 and 6.0, respectively, for LACC-AuNPs-CS/GPE and TYR-AuNPs-CS/GPE. These results are in accordance to those reported for other individual LACC-and TYR-based biosensors [8,[49][50][51]. By using both enzymes at the optimum ratio (2.0:1.0, w/w), the peak current was enhanced ca.…”

Enhancing catalytic performance of laccase via immobilization on chitosan/CeO 2 microspheres

“…In particular, Trametes versicolor laccase (Tvl) is a fungal laccase containing four copper ions located in sites denoted T1, T2, and T3 in the active center of the enzyme [5]. This laccase can oxidize a wide range of xenobiotic compounds, such as synthetic dyes, chlorinated phenolics, and polycyclic aromatic hydrocarbons [6].…”

Micro‐ and Nanoscopic Imaging of Enzymatic Electrodes: A Review

“…Trametes versicolor laccase was immobilized on gold following three different strategies: adsorption, covalent attachment, encapsulation in a three‐dimensional sol‐gel matrix. AFM allowed saying if enzymes formed monomers or aggregates (thanks to lateral resolution of the spots), if enzyme layers were compact, and if monolayers were formed . Adsorbed enzymes formed a compact layer on top of which SM or aggregates accumulated (height values >10 nm).…”