Controlling the Surface Functionalization of Ultrasmall Gold Nanoparticles by Sequence-Defined Macromolecules.
Selina Beatrice van der MeerTheresa SeilerChristin BuchmannGeorgia PartalidouSophia BodenKateryna LozaMarc HeggenJürgen LindersOleg PrymakCristiano L P OliveiraLaura HartmannMatthias EpplePublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2020)
Ultrasmall gold nanoparticles (diameter about 2 nm) were surface-functionalized with cysteine-carrying precision macromolecules. These consisted of sequence-defined oligo(amidoamine)s (OAAs) with either two or six cysteine molecules for binding to the gold surface and either with or without a PEG chain (3400 Da). They were characterized by 1 H NMR spectroscopy, 1 H NMR diffusion-ordered spectroscopy (DOSY), small-angle X-ray scattering (SAXS), and high-resolution transmission electron microscopy. The number of precision macromolecules per nanoparticle was determined after fluorescent labeling by UV spectroscopy and also by quantitative 1 H NMR spectroscopy. Each nanoparticle carried between 40 and 100 OAA ligands, depending on the number of cysteine units per OAA. The footprint of each ligand was about 0.074 nm2 per cysteine molecule. OAAs are well suited to stabilize ultrasmall gold nanoparticles by selective surface conjugation and can be used to selectively cover their surface. The presence of the PEG chain considerably increased the hydrodynamic diameter of both dissolved macromolecules and macromolecule-conjugated gold nanoparticles.
Keyphrases
- gold nanoparticles
- high resolution
- living cells
- iron oxide
- reduced graphene oxide
- fluorescent probe
- electron microscopy
- photodynamic therapy
- drug delivery
- solid state
- magnetic resonance
- mass spectrometry
- magnetic resonance imaging
- tandem mass spectrometry
- computed tomography
- high speed
- molecularly imprinted
- amino acid
- aqueous solution