title: The gold/ampicillin interface at the atomic scale.
abstract: In the fight against antibiotic resistance, gold nanoparticles (AuNP) with antibiotics grafted on their surfaces have been found to be potent agents. Ampicillin-conjugated AuNPs have been thus reported to overcome highly ampicillin-resistant bacteria. However, the structure at the atomic scale of these hybrid systems remains misunderstood. In this paper, the structure of the interface between an ampicillin molecule AMP and three flat gold facets Au(111), Au(110) and Au(100) has been investigated with numerical simulations (dispersion-corrected DFT). Adsorption energies, bond distances and electron densities indicate that the adsorption of AMP on these facets goes through multiple partially covalent bonding. The stability of the AuNP/AMP nanoconjugates is explained by large adsorption energies and their potential antibacterial activity is discussed on the basis of the constrained spatial orientation of the grafted antibiotic.
authors.affiliation: CEMES CNRS UPR 8011 and Université de Toulouse, 29 rue Jeanne Marvig, BP 94347, 31055 Toulouse cedex 4, France. nathalie.tarrat@cemes.fr.
authors.forename: N
authors.initials: N
authors.lastname: Tarrat
authors.forename: M
authors.initials: M
authors.lastname: Benoit
authors.forename: M
authors.initials: M
authors.lastname: Giraud
authors.forename: A
authors.initials: A
authors.lastname: Ponchet
authors.forename: M J
authors.initials: MJ
authors.lastname: Casanove
mesh_terms: D000327:Adsorption; D000667:Ampicillin / Q000737:chemistry* / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D058726:Nanoconjugates / Q000737:chemistry*; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D000900:Anti-Bacterial Agents; D058726:Nanoconjugates; D006046:Gold; D000667:Ampicillin