Confined Unimolecular Micelles for Precisely Controlled In Situ Synthesis of Stable Ultrasmall Metal Nanocluster Assemblies

Abstract

Ultrasmall noble metal nanoclusters (NCs; core size, <2 nm) with a high surface atomic ratio and a tunable electronic structure have attracted intensive interest; however, the controlled preparation of stable metal NC assemblies is still a challenge. Here, star-like diblock copolymer unimolecular micelles were used as a universal and robust scaffold to synthesize ultrasmall metal NC assemblies with a controlled size and amount of metal NCs (10–160). The size of the NC assemblies can also be controlled by changing the length of the P4VP block of the star-like polymers via atom transfer radical polymerization. The thiolate ligands play an important role in the control of the size of individual nanoclusters and largely enhance the stability of the NC assemblies. The as-synthesized stable ultrasmall metal NC assemblies will have broad application prospects in the fields of catalysis, optics, and biomedicine.

Stepwise-Enhanced Tumor Targeting of Near-Infrared Emissive Au Nanoclusters with High Quantum Yields and Long-Term Stability

“…The photoluminescence of AuNCs is closely related to the core sizes of the AuNCs, choice of ligands, and coverage densities of ligands. , In addition, the introduction of other metal elements − and the promotion of charge transfer between the ligands and metals , can enhance the photoluminescence efficiency. Alternatively, the creation of a rigid environment by spatial confinement by proteins, − polymers, − or the assembly of NCs − can also promote photoluminescence due to the restriction of non-radiative relaxations. Despite significant progress, AuNCs that were prepared under aqueous system, exhibiting near-infrared (NIR) emission, still suffer from low quantum yields.…”

“…In Vitro and In Vivo MRI Experiments. The AuNCs@PF solution with different concentrations (12,24,30,36,48, and 60 mg mL −1 ) was prepared for in vitro MRI imaging. The AuNCs@PF solution (30 mg mL −1 in PBS, 100 μL) was intratumorally injected into the tumor-bearing mice.…”

Modulating luminescence and assembled shapes of ultrasmall Au nanoparticles towards hierarchical information encryption

“…32 In this approach, amphiphilic block copolymers could be rationally designed by manipulating the block segments and assembled to build uniform micelles with controllable size and shape, which could be used as nanoreactors for the growth and assembly of NPs. 33,34 Besides, the optical features of the building block, ultrasmall Au NPs, could be easily in-situ tuned by controlling experimental conditions, including the concentration of the precursors, type of stabilizers and reducing agents to reach the multicolor emissions and enhancement of luminescence and stability. 35,36 The distinct assembled structures with tunable emission and controllable morphology may provide a new route to make stored information more security and robustness due to difficulties in imitating and enhanced stability.…”

Construction of 3D Ordered Honeycomb Films with Controllable Pores as Efficient Catalytic Supports

“…[ 9 ] The stability and uniform distribution of nanoparticles play crucial roles in the nanocomposites, since the NPs aggregation due to their highly active surface atoms subsequently leads to reduced catalytic activity. [ 10 ] In addition, the recovery and recyclable use of catalysts are also great economic obstacles, limiting their practical applications. [ 11 ] Therefore, the development of nanocomposites with both efficient NPs stabilization and facile recyclability for tailored applications remains a tremendous challenge.…”