Enzyme Immobilization by Amperometric Biosensors with TiO2 Nanoparticles Used to Detect Phenol Compounds

Abstract

Nanoparticles of titanium dioxide (TiO 2 ) have unique properties in creating an appropriate microenvironment for immobilizing biomolecules without loss of biological activity, and facilitating electron transference between the enzyme and surface of the electrode. TiO 2 properties have led to its intensive use in building electrochemical biosensors. Another aspect is, the chemical process of sol-gel which offers new and interesting advantages in the encapsulation of biomolecules sensitive to heat and environmental conditions (enzymes, proteins, antibodies, and cells from plants, animals and micro-organisms), mainly due to a synthesized process at low temperatures. The nanomaterials produced by sol-gel have many advantages, including chemical inertia, physical rigidity, insignificant swelling in an aqueous medium, and porosity. For this reason, electrochemical biosensors consisting of nanomaterials have been extensively investigated and used in important industrial sectors, such as, those of pharmaceuticals, health, food, agriculture, and environment. They provide real-time data, which allows the control and traceability of each of the processes involved. Biosensors are devices that consist of one element of molecular recognition (biomolecules) and one transduction element. The objective of this work is to conduct a review of electrochemical biosensors using nanoparticles obtained from the sol-gel process and their potential application to measure phenol compounds.

Electrochemical Study and Characterization of an Amperometric Biosensor Based on the Immobilization of Laccase in a Nanostructure of TiO2 Synthesized by the Sol-Gel Method

“…Due to their good reproducibility, selectivity, high sensitivity, and miniaturization effect, electrochemical techniques, notably amperometric biosensors, stand out as the best candidates for the detection of polyphenols [ 1 , 6 , 8 , 9 , 10 , 11 , 12 , 13 ].…”

“…In recent years, biosensors, modified with oxidoreductase enzymes (tyrosinase, laccase, peroxidase or cellobiose dehydrogenase), have been developed for the detection of phenolic compounds, since phenols can act as electron donors for said enzymes [ 11 , 14 , 15 , 16 ].…”

“…In general, laccase contains four copper atoms classified into type 1 (T1), type 2 (T2), and type 3 (T3), according to their spectroscopic and magnetic properties. T1, the substrate-binding site of the enzyme, is involved in the oxidation of the substrate and the transfer of electrons to the T2/T3 cluster, while T3 is responsible for oxygen uptake and, as a whole, the T2/T3 site is responsible for the reduction of O 2 to water [ 9 , 11 , 14 , 15 , 16 , 17 , 18 ]. Enzyme immobilization is the key step in the fabrication of a sensitive and stable biosensor.…”

“…The search for a novel immobilization system, together with an advanced material used to immobilize laccase in amperometric biosensor construction, continues to fascinate those working in the field. In recent years, sol-gel materials have emerged as one type of potentially attractive matrix, well suited for the said immobilization of enzymes in biosensor construction [ 8 , 10 , 11 , 20 , 21 , 22 ]. Sol-gel technology provides a unique means for preparing a three-dimensional network suitable for the encapsulation of a variety of biomolecules, because they can be prepared under ambient conditions, and they exhibit tunable porosity, high thermal stability and chemical inertness, plus they demonstrate negligible swelling in an aqueous solution.…”

Metal oxide nanostructures for sensor applications

“…Another study demonstrated the enzyme immobilization by amperometric biosensors with TiO2 nanoparticles to detect phenol compounds [258].…”