Preparação e caracterização de híbridos a partir da silanização da magnetita visando a imobilização da glicose oxidase (GOX).

Abstract

With the increasing number of cases of people with diabetes in recent years, and in view of the existing biosensor technology still has a high cost-benefit ratio, found himself in a race last decade the development of biosensors for detection of glucose based on the immobilization of glucose oxidase mainly using functionalized magnetic nanoparticles of magnetite agents silanes. Thus, this dissertation developed a material capable of immobilizing glucose oxidase. For this purpose it has been proposed to obtain a hybrid material from magnetic nanoparticles (NPMs) magnetite (Fe304) surface modified with silane agent, 3- aminopropyltriethoxysilane (APTES) .To assess the product obtained regarding the effect of the silane agent in the modification of the properties of NPMs analyzes were performed characterization of X-ray diffraction (XRD), spectroscopy in the Fourier transform infrared (FTIR), thermogravimetric analysis, scanning electronic microscopy (SEM) and magnetic measurements in vitro test magnetic separation and sedimentation. To evaluate the interaction of NMPs with and without silane agent test was performed immobilization of glucose oxidase. The results obtained showed that the surface modification of Fe304 NPMs silane agent APTES was successfully achieved since the silanization process did not alter the characteristic of the structural and morphological magnetic product. The magnetite samples before and after the silanization were non-cytotoxic and it has high cell viability. The immobilized glucose oxidase was obtained, with 0,006mg/g for pure magnetite and 0,008mg/g for the hybrid Fe304/Si02 . The type of chemical interaction (physical adsorption or covalent) between the glucose oxidase (GOX) and NPMs, before and after the immobilization, were influenced by silanization. These reveals that magnetite and the hybrid Fe304 / S i 0 2 are carriers for GOX immobilization and the immobilized GOX has great potential application in developing glucose biosensors.