One of the most notable developments in nanotechnology has been its application in the biomedical world. Nanoparticles are now common agents for drug delivery and cancer therapy as well as noninvasive sensors and detectors, and surface coatings that have direct contact with biological systems. However, molecular level detail regarding how amino acids, peptides and proteins are structured and organize on nanoparticles remains poorly understood. One thrust in our research group is elucidating the interface between nanoparticles and amino acids so that we can better understand and predict how a given peptide or protein will bind and organize on a nanoparticle. Solid-state nuclear magnetic resonance (SSNMR), thermogravimetric analysis (TGA), and molecular modeling have been used to probe the interface between L-histidine (His) and fumed silica nanoparticles. Various loading levels of isotopically enriched (13C/15N) His were analyzed with one (1D) and two-dimensional (2D) magic angle spinning (MAS) SSNMR techniques. Homonuclear and heteronucler (HETCOR) correlation experiments as well as proton-detection methods were employed to elucidate the binding mechanism. Experimental isotropic chemical shifts are compared with computational density functional theory (DFT) values to optimize structural models. Analysis of L-Hisitinde monochloride monohydride was also compared to determine if the presence of salt impacts binding. TGA results illustrate the formation of peptide bonds through condensation reactions and are being further analyzed to determine how His binds and behaves on the silica surface. His is one of the most ubiquitous amino acids in known silica binding peptides and it is anticipated that these results will aid other researchers in determining how peptides and proteins bind silica surfaces and advance our understanding of the nano-bio interface.

Elucidating the structure and assembly of amino acids on silica nanoparticles

251st National Meeting (2016)

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