Síntesis de sensores colorimétricos soportados para quimisorción de moléculas biológicas

VIRGINIA ROLDÁN ; NORA PELLEGRI

Santa Fe

Congreso; Congreso Internacional de Metalurgia y Materiales; 2014

SAM-Asociación Argentina de Materiales

In recent years, colorimetric assays based on metal nanoparticles acquired great interest because they are simple, low cost,fast responsive ang highly sensitive techniques. Metal nanoparticles show typical absorption bands in the UV-Vis spectrum due the collective oscilation of the conduction electrons (LSPR, Local Surface Plasmon resonance). A lot of experimental and theorethical data have demonstrated the high sensitivity of the maximum absorption LSPR respect to changes of the surrounding refractive index. From this knowledge, a lot of efforts were dedicated to the development of LSPR-based sensors and several examples can be found in the more recent bibliography. Some examples, have demonstred also that the anoparticle surface can be modified to increase the sensitivity and selectivity. However, the characteristics of these sensors could be improved even further. Thus, for example, the obtaining of sensors supported by solids apper as a new challenge to obtain dispositives easier to manipulate than the same in colloidal suspension. To prepare sensors supported by a solid we use a sol-gel technique to obtain coatings onto glass substrates. The obtained composites were composed by silver nanoparticles, an inorganic SiO2 matrix and amine treminated organic compounds. In the first step, aminesilane-stabilized silver nanoparticles in colloidal suspension were obtained by chemical reduction. On the other hand, a SiO2 sol was obtained from hydrolisis and condensation of TEOS. Both precursors were mixed and coatings were deposited on glass substrates by dipping.Samples were washing and drying. After this process coatings functionalized with amine groups were obtained. These coatings are useful to a subsequent quimisortion of biological moleculesable to ats as selective groups.