Executive Summary: The development of simple and reliable biosensors for enzyme immobilization is essential and represents one of the emerging areas in nanotechnology.
The detection of biomolecules is of enormous interest in the areas of health, environment and food, in this sense there is a growing interest in the use of nanomaterials for this purpose, and specifically carbon nanotubes (NTC) offer the possibility of developing devices with high sensitivity, selective, fast, reliable and cheap, which can have a high impact in the country in the biomedical area. Thus, CNTs constitute the new generation of ultrafast and ultrasensitive biosensor systems [1-3]. CNTs are characterized by their high surface area, their excellent electrical, mechanical and electrochemical properties. On the other hand, their electronic transfer capacity is responsible for the rapid response time, and they are highly stable systems.
The modification of the walls of the CNT with different nanoparticles, can strongly improve the behavior of these to immobilize enzymes. Several materials have been used for this modification, among them titanium dioxide nanoparticles, due to its strong photo-oxidant potential, high chemical stability and wide band-gap, which gives it a very wide range of applications, which include biosensors. and solar cells and photocatalysis. On the other hand, nanostructured zirconia has been proposed as a biomarker in the detection of oral cancer [4-7] and also for immobilization of enzymes under mild conditions [8]. Hydroxyapatite has a high biomolecule adsorption capacity, in addition to its excellent biocompatibility.
Therefore, the combination of CNTs coated with titanium dioxide, zirconium dioxide or hydroxyapatite nanoparticles has the advantage, apart from improving biocompatibility, of taking advantage of the properties of these nanoparticles that, combined with CNTs, can offer a synergistic effect as biosensors. .
Considering the above, the purpose of the following work is to obtain and characterize nanostructured systems based on the coating of CNT with different materials, such as TiO2, ZrO2, HAp and their combinations; as well as adding Silver (Ag) nanoparticles to some nanostructures and using them as biosensors for immobilization of different enzymes, these are external devices, with which an electrochemical response will be measured when a specific enzyme is adsorbed directly on the surface of the electrode formed by a support on which the modified carbon nanotubes are placed, with an improvement in the direct transfer of electrons. Glucose oxidase will be used as the standard enzyme, which is an oxidoreductase that catalyzes the oxidation of glucose.
Objectives General: Obtain and characterize nanostructured systems based on carbon nanotubes coated with titania, zirconia and hydroxyapatite, with and without the inclusion of silver particles, for various applications such as biosensors for enzyme immobilization.
Specific objectives:
- Purify and Functionalize carbon nanotubes using an oxidative method.
- Obtain nanostructured composite materials by coating carbon nanotubes with titania and zirconia, at two mass concentrations of the carbon nanotube, two gel aging times, with and without heat treatment.
- Coat the nanostructured materials composed of carbon nanotubes coated with titania and zirconia with hydroxyapatite, using the chemical precipitation method and by immersion in a SBF solution.
- Insert silver particles into nanostructured materials based on carbon nanotubes coated with titania and zirconia, using the wet impregnation method and the polyol method.
- Thermally, morphologically and structurally characterize the nanostructured systems obtained.
- To determine the effect of the concentration of the carbon nanotube, the aging time of the gel and the heat treatment on the thermal, morphological and structural properties of the different compounds obtained.
- Design enzymatic biosensors, and carry out enzyme activity tests with glucose oxidase as a pattern.
Participating Institutions:
PUCE, YACHAY TECH, EPN, ESPOL.
Participants:
Project Director Dr. Patricio Espinoza.
Co-director Gema González.
- Patricio J. Espinoza Montero
- Lenys Fernandez
- gem gonzalez
- Anthony Diaz
- Andrew Geottffrey
- Mayra Mora
- rafael uribe
- Luis Lascano
- Ana Rivas
Awarded budget: $69652
Project status: Signing of agreements.
