engleski

COMBINED NMR AND COMPUTATIONAL STUDY OF L-DOPA AND DOPAMINE OXIDATION UPON INTERACTION WITH GOLD NANOSURFACE

The great potential of gold nanoparticles (AuNPs) functionalized with catechols, dopamine and L-DOPA, in biomedical applications prompts the need for evaluation of their interaction at the nano-bio interface.[1] In the presence of gold slats, catechols are known to transform by various pathways including oxidation, cyclization and polymerization.[2] Thus, different transformation patterns should be considered in order to avoid binding the structurally changed molecule to the nanosurface while preventing unpredictable consequences for the health status of an organism. In this study, the fate of functionalization agents upon interaction with gold nanosurface was investigated by combining nuclear magnetic resonance (NMR) spectroscopy and a computational approach. Experimental results revealed that the final form of catechol on the AuNPs nanosurface depends on the molar ratio of reactant used in synthesis. The oxidation of both L-DOPA and dopamine was promoted in the case of molar excess of Au. However, their final products differ as L-DOPA underwent intramolecular cyclization. Computational simulations using density functional theory (DFT) and molecular dynamics (MD) methods revealed the mechanism that stays behind this difference and clarified the most likely candidates, among different oxidation products, for binding to the AuNPs surface. The obtained results represent valuable mechanistic data about the binding events at the surface of AuNPs to encourage their application in biomedicine.

gold nanoparticle, DOPA, dopamine, NMR, in silico

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