Biosensors uses biomolecules to recognize certain element, and generate a signal that is translated to a biorecognition event, and later quantified. New materials, and principally materials formed by the controlled self-assembly of nucleotides are a promising alternative to the area. Due to the low experimental cost, simplicity, stability and fast response, they attract a lot of attention, however many of its physical-chemical properties are not stablished. In this project, it is proposed the study of the structure properties and its relation with the generated electrochemical signal of DNA based nanostructures. To accomplish it two strategies will be followed, the first uses short DNA strands to promote the self-assembly of three-dimensional crystalline super lattices of gold nanoparticles with controlled orientation. To that, first gold nanoparticles will be modified with thiolated DNA strands, and later will be assembled in films of nanoparticles with body centered cubic unit cell in two distinct orientations (100) and (110) on gold electrodes. The self-assembly process, and the electrochemical properties will be studied in function of the number of layers, nanoparticles diameter and orientation of the crystallographic plane, in that way we expect to achieve controlled electrochemical response by controlling the structure of the film. The second proposal is the use of DNA nanotetrahedrons, this kind of nanostructure presents great stability and easy preparation procedures, more than that it forms thin films with excellent control of surface coverage. It is proposed here the study the electrode surface modification process and study the electrochemical properties of it. With the obtained results, it is proposed the use of the novel interfaces to the development of application in integrated bio-sensors with enhanced sensibility, stability, linear range and lower detection limits levels.
News published in Agência FAPESP Newsletter about the scholarship: