Organic chemistry

Our research interset focuses on the investigation of the stabilization of natural dyes. Our main method for achieving improved stability is via immobilization onto metal oxide nanoparticles. Investigation of the molecular aspects of this binding mode is challenging, as we are looking at Mw ≤ 500 g/mol molecules grafted onto relatively large nanoparticles. This typically leads the dye of interest to a minority of the weight/volume in the final product we would like to study - the dyed nanoparticles (DNPs). With poor solubility of DNPs, most techniques (e.g. TGA, liqud-state NMR) only give a poor signal for analysis. One way to alleviate the issue of solubility is the use of magic-angle spinning (MAS) solid-state NMR (ssNMR), where a solid sample is measured, and solubilization of the product is not necessary. By comparing the ssNMR spectra of both the natural dye and the DNPs together with the liquid-state NMR signals of the natural dye (both 1H and 13C), we can identify the changes in the chemical environment of the dye upon binding to the nanoparticles at the atomic level, therfore facilitating the understanding of the binding mode.