Title
Realizing Enhanced Luminescence of Silver Nanoclusters-Peptide Soft Hydrogels by PEI Reinforcement
Author
Xia Xin, Yuanyuan Gao, Qingyu Zhang, Zhi Wang, Di Sun, Shiling Yuan, Haibing Xia
Year
2018
Journal
Soft Matter
Abstract
Metal nanoclusters (NCs) are a new type of fluorescent nanomaterials composed of several to several tens of metal ions or atoms with a wide range of applications in the fields of catalysis, optics, and biomedicine. However, the fluorescence quenching when existing as individuals in aqueous solutions greatly limits their applications. In this study, six-core Ag(I) NCs (Ag6-NCs) were interacted with peptides (DD-5) in water to form soft hydrogels with aggregation-induced emission (AIE) of Ag6-NCs. The introduction of polyethyleneimine (PEI) into the Ag6-NCs/DD-5 hydrogel succeeded in further enhancing the fluorescence intensity. This dual-AIE behavior of Ag6-NCs/DD-5/PEI hydrogels is mainly ascribed to the strong hydrogen bonding among the carboxyls of Ag6, those of DD-5 and the amino groups of PEI, which effectively restricted intramolecular vibration of the capping ligands on Ag6-NCs. Moreover, the addition of PEI can effectively promote the gelation speed of Ag6-NCs/DD-5 and act as a physical cross-linker, leading to an increase of the mechanical strength of the hydrogel. This work opens a new pathway for the fabrication of smart composite materials with multiple functions, which show a variety of applications such as chemical/biosensing and bioimaging.
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Chemical stability, Nanostructures, Materials, Biochemistry