Chiral ceramic nanoparticles and peptide catalysis
Demir, Hilmi Volkan
Kotov, N. A.
Journal of the American Chemical Society
American Chemical Society
13701 - 13712
Item Usage Stats
MetadataShow full item record
The chirality of nanoparticles (NPs) and their assemblies has been investigated predominantly for noble metals and II-VI semiconductors. However, ceramic NPs represent the majority of nanoscale materials in nature. The robustness and other innate properties of ceramics offer technological opportunities in catalysis, biomedical sciences, and optics. Here we report the preparation of chiral ceramic NPs, as represented by tungsten oxide hydrate, WO3-x·H2O, dispersed in ethanol. The chirality of the metal oxide core, with an average size of ca. 1.6 nm, is imparted by proline (Pro) and aspartic acid (Asp) ligands via bio-to-nano chirality transfer. The amino acids are attached to the NP surface through C-O-W linkages formed from dissociated carboxyl groups and through amino groups weakly coordinated to the NP surface. Surprisingly, the dominant circular dichroism bands for NPs coated by Pro and Asp are different despite the similarity in the geometry of the NPs; they are positioned at 400-700 nm and 500-1100 nm for Pro- and Asp-modified NPs, respectively. The differences in the spectral positions of the main chiroptical band for the two types of NPs are associated with the molecular binding of the two amino acids to the NP surface; Asp has one additional C-O-W linkage compared to Pro, resulting in stronger distortion of the inorganic crystal lattice and greater intensity of CD bands associated with the chirality of the inorganic core. The chirality of WO3-x·H2O atomic structure is confirmed by atomistic molecular dynamics simulations. The proximity of the amino acids to the mineral surface is associated with the catalytic abilities of WO3-x·H2O NPs. We found that NPs facilitate formation of peptide bonds, leading to Asp-Asp and Asp-Pro dipeptides. The chiroptical activity, chemical reactivity, and biocompatibility of tungsten oxide create a unique combination of properties relevant to chiral optics, chemical technologies, and biomedicine.
Crystal atomic structure
Atomistic molecular dynamics simulations
Published Version (Please cite this version)http://dx.doi.org/10.1021/jacs.7b01445
Showing items related by title, author, creator and subject.
One-step synthesis of size-tunable Ag nanoparticles incorporated in electrospun PVA/cyclodextrin nanofibers Celebioglu A.; Aytac Z.; Umu, O. C. O.; Dana, A.; Tekinay, T.; Uyar T. (Pergamon Press, 2014)One-step synthesis of size-tunable silver nanoparticles (Ag-NP) incorporated into electrospun nanofibers was achieved. Initially, in situ reduction of silver salt (AgNO3) to Ag-NP was carried out in aqueous solution of ...
In situ synthesis of biomolecule encapsulated gold-cross-linked poly(ethylene glycol) nanocomposite as biosensing platform: A model study Odaci, D.; Kahveci, M.U.; Sahkulubey, E.L.; Ozdemir, C.; Uyar T.; Timur, S.; Yagci Y. (Elsevier BV, 2010)In situ synthesis of poly(ethylene glycol) (PEG) hydrogels containing gold nanoparticles(AuNPs) and glucose oxidase (GOx) enzyme by photo-induced electron transfer process was reported here and applied in electrochemical ...