Chiral gold nanoparticles applied to enantiodiscrimination

Abstract

Enantiomers are isomers that have the same molecular formula but are non-superimposable mirror images of each other due to the presence of an asymmetric carbon. They can interact differently in the human body or other systems, making their separation crucial, as one may be medicinal and the other toxic or inactive.Nuclear Magnetic Resonance (NMR) stands out for elucidating these compounds, but the NMR spectrum does not distinguish enantiomers without a chiral environment. To overcome this limitation, the Matrix-Assisted DOSY (MAD) technique will be applied to systems containing gold nanoparticles (AuNPs) functionalized with chiral solvating agents (CSA), such as the amino acid cysteine or the peptide glutathione, to modify diffusion properties and allow the separation of a series of enantiomers in the NMR frequency dimension.The nanoparticles will be synthesized and functionalized following procedures described in the literature and characterized using Ultraviolet-Visible absorption spectroscopy (UV-Vis), Dynamic Light Scattering (DLS), and Circular Dichroism (CD). Subsequently, they will be analyzed by NMR in samples containing mixtures of the enantiomers of camphor, menthol, mandelic acid, and Mosher's acid. The project aims to explore the selectivity of gold nanoparticles and assess the benefits of their use as chemosensors using the Matrix-Assisted DOSY technique in enantiomer discrimination.