Synthesis and characterization of engineered self-assembly peptides for sensing application

The self-assembly of materials is a key technique for the design and production of nanostructured systems and has become a fundamental method for the construction of advanced materials and their application in the fields of nanomaterials and biotechnology. In the self-assembly of nanomaterials, the unique and dynamic interaction between disordered building blocks drives towards the spontaneous formation of more ordered (or more organized) nanostructured systems. Main examples of the self-assembly method are found in biomolecules, where the interaction of various macromolecular components and the synergy of their interactions allow the establishment of highly specific functions of biological interest. For example, folding of a polypeptide chain within a protein or conformational changes of nucleic acids into a variety of functional forms are relevant examples of self-assembly processes, involved in many biological processes. The construction of functional materials at the atomic and molecular level requires structural control and research at the nanoscale for which there are instrumentation techniques and observation methods on such size scales (TEM, SEM, UV-Vis spectrophotometry etc). Nowadays, the development of multifunctional nanosystems and biomaterials uses supramolecular chemistry through the bottom-up principle as a general process for self-assembly. In this thesis we evaluated the ability to combine synergies between gold nanoparticles and appropriately functionalized biomolecules in such a way as to create new self-assembling systems that combine the properties of both parts, generating new implemented chemical and physical functions. Specifically, in this thesis we have faced the synthesis of nanosystems based on gold nanoparticles functionalized with various ligands and then moved on to the development of self-assembling biomolecules, in particular molecules based on diacetylenes, modified peptides and MOFs (metal-organic frameworks). These biomaterials were characterized thanks to the use of appropriate techniques (fluorescence optical microscopy, SEM, NMR, CD and UV-Vis spectrophotometry).