This Technical Specification provides guidelines for the identification of the surface bound molecules using FT-IR of dehydrated gold nanoparticle (AuNPs) films both before and after nanomaterial (NM) cytotoxicity testing.

NOTE 1 AuNPs may have surface bound ligands prior to testing and may be additionally covered (or coated) with organic- or bio-molecules during the cytotoxicity test.

NOTE 2 Nucleic acids, amino acids, lipids or membrane components binding to AuNPs can be observed by FT-IR spectroscopy by detection of absorption bands corresponding to phosphodiester, amine or lipid, respectively, although the type of nucleic acids, proteins or lipid cannot be identified in detail based on IR spectra.