Novel nanobiotechnology platforms based on photochromic molecules

The development of new nano-biotechnologies is a promising and ever demanding research field. In particular, the possibility to use the organic chemistry tools to build molecules sensitive to a wide range of external stimuli, responsible of a switching between their two isomers, represents an interesting area of investigation with suitable applications in novel nano-technologies. The use of photochromic molecular switches in applications ranging from drug delivery to the probing of biochemical parameters, passing through their uses in material science, in polymer and carbon nano materials realms, constitute the main research subject of my PhD course. In this manuscript I\u2019ll report in Chapter 3 investigations upon Spiropyrans molecular switches in their metal complexations attitude for the Visible light regulated delivery of pharmaceutical active compounds. Chapter 4 will be dedicated to the study I conducted on hybrid mesostructures prepared combining Azobenzenes molecules and Graphene Oxide in order to apply these modified materials in the biological context. Chapter 5 will be instead dedicated to the study of photochromic Oxazines and Oxazolidines in their modifications with fluorophores to have ratiometric Temperature and pH sensing tools and in their use as switchable blocks in photo-modulable polymers

Photo-responsive graphene and carbon nanotubes to control and tackle biological systems

Photo-responsive multifunctional nanomaterials are receiving considerable attention for biological applications because of their unique properties. The functionalization of the surface of carbon nanotubes (CNTs) and graphene, among other carbon based nanomaterials, with molecular switches that exhibit reversible transformations between two or more isomers in response to different kind of external stimuli, such as electromagnetic radiation, temperature and pH, has allowed the control of the optical and electrical properties of the nanomaterial. Light-controlled molecular switches, such as azobenzene and spiropyran, have attracted a lot of attention for nanomaterial's functionalization because of the remote modulation of their physicochemical properties using light stimulus. The enhanced properties of the hybrid materials obtained from the coupling of carbon based nanomaterials with light-responsive switches has enabled the fabrication of smart devices for various biological applications, including drug delivery, bioimaging and nanobiosensors. In this review, we highlight the properties of photo-responsive carbon nanomaterials obtained by the conjugation of CNTs and graphene with azobenzenes and spiropyrans molecules to investigate biological systems, devising possible future directions in the field

Behavior of Ternary Mixtures of Hydrogen Bond Acceptors and Donors in Terms of Band Gap Energies

Three ternary mixtures composed by choline chloride (ChCl), ethylene glycol (EG), and a second hydrogen bond donor (HBD) as ethanol (A), 2-propanol (B), and glycerol (C) were studied in terms of composition related to the band gap energy (BGE). A Design of Experiments (DoE) approach, and in particular a Simple Lattice three-components design, was employed for determining the variation of the BGE upon the composition of each system. UV-VIS analysis and subsequent Tauc plot methodology provided the data requested from the DoE, and multivariate statistical analysis revealed a drop of the BGE in correspondence to specific binary compositions for systems A and B. In particular, a BGE of 3.85 eV was registered for the mixtures ChCl/EtOH (1:1) and ChCl/2-propanol (1:1), which represents one of the lowest values ever observed for these systems