A facile approach was developed to prepare positively charged and red-emitting lysozyme-stabilized Ag nanoclusters (Lys-AgNCs) using NaBH₄ as a reducing agent at room temperature. The Lys-AgNCs can be applied in the highly selective detection of Hg²⁺.
A facile one-pot sonochemical approach is presented to prepare highly blue-emitting Ag nanoclusters (AgNCs) using glutathione as a stabilizing agent in aqueous solution. The as-prepared AgNCs can be applied in the selective detection of S(2-) with a limit of detection of 2 nM based on fluorescence quenching.
In this paper, the development of a simple method is described for preparing highly red fluorescent mercaptosuccinic acid stabilized AgAu alloy nanoclusters (MSA-AgAu NCs) through the core etching of Ag nanoparticles (NPs) and a galvanic exchange reaction using nonorganic solvent and no multistep centrifuge washing. The as-prepared MSA-AgAu NCs were characterized using spectroscopic and microscopic techniques. After covalently attaching methoxy-poly(ethylene glycol)-NH2 (m-PEG-NH2), PEGylated MSA-AgAu NCs were still stable even in 1 M NaCl. Probably based on the deposition of Al(3+)-enhanced fluorescence, the PEGylated MSA-AgAu NCs offered highly selective and sensitive sensing of Al(3+) in aqueous solution with a detection limit of 0.8 μM.
Assembling instable
ultrasmall nanoparticles (NPs) into uniform
nanoarchitectures with excellent stability and controllability in
aqueous solution is still challenging. Herein, taking the advantage
of controllable size and shape of amphiphilic triblock copolymer template,
we report a facile and robust strategy for in situ fabrication of highly luminescent Cu nanoassemblies with uniform
morphology and remarkable stability. The dominant number of encapsulated
CuNPs in an assembly can be controlled through regulating hydrophobic
core size by varying block segments of the template. The cross-linking
by a multidentate thiol ligand largely enhances the emission and stability
of the Cu nanoassemblies in physiological environment. By virtue of
their intriguing features, the Cu nanoassemblies can be applied to
possible biomedical applications. These findings establish our approach
as a facile and feasible method for preparing stable and well-controlled
ultrasmall metal NP-based assemblies.
The surface chemistry of the ultrasmall thiolated gold nanoparticles (AuNPs, < 3.0 nm) plays key roles in both governing the intrinsic emission and establishing interfaces surrounded by various amine‐containing biomolecules in the biomedical applications such as imaging, targeting, and diagnostics. However, a fundamental understanding of the surface ligand's role in the stimuli‐responsive emissions of AuNPs toward the amine molecules is currently lacking. Here, through investigation of the thiolate surface and exotic amine structures, it is discovered that the nucleophilic amines tend to closely bind the electrophilic gold surface, generating a high‐energy stimuli‐responsive emission from the low‐energy intrinsically emitting AuNPs. Both the intrinsic and stimuli‐responsive emissions show a unique amine concentration‐dependent ratiometric pattern for quantitative assessments of important biogenic amines in the biological samples. This discovery opens a new pathway to the design of stimuli‐responsive AuNPs, and would promote more experimental and theoretical research on the application‐driven surface engineering for advanced biological applications.
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