Self‐Assembly of Precision Noble Metal Nanoclusters: Hierarchical Structural Complexity, Colloidal Superstructures, and Applications

Abstract

Ligand protected noble metal nanoparticles are excellent building blocks for colloidal self‐assembly. Metal nanoparticle self‐assembly offers routes for a wide range of multifunctional nanomaterials with enhanced optoelectronic properties. The emergence of atomically precise monolayer thiol‐protected noble metal nanoclusters has overcome numerous challenges such as uncontrolled aggregation, polydispersity, and directionalities faced in plasmonic nanoparticle self‐assemblies. Because of their well‐defined molecular compositions, enhanced stability, and diverse surface functionalities, nanoclusters offer an excellent platform for developing colloidal superstructures via the self‐assembly driven by surface ligands and metal cores. More importantly, recent reports have also revealed the hierarchical structural complexity of several nanoclusters. In this review, the formulation and periodic self‐assembly of different noble metal nanoclusters are focused upon. Further, self‐assembly induced amplification of physicochemical properties, and their potential applications in molecular recognition, sensing, gas storage, device fabrication, bioimaging, therapeutics, and catalysis are discussed. The topics covered in this review are extensively associated with state‐of‐the‐art achievements in the field of precision noble metal nanoclusters.

Methylcellulose–Cellulose Nanocrystal Composites for Optomechanically Tunable Hydrogels and Fibers

“…Therefore, as is acknowledged from the start, the aim of the MC-based optical fibers is not to pursue superior long-distance performance and usurp the GOFs; the additional loss caused by the dopants may often be acceptable and not compromise the envisioned applications. Moreover, the dopants may allow multifunctional optical fibers by coupling the material with sensory or luminescent properties, or higher tunable mechanical strength, as has been demonstrated via the addition of gold nanoclusters (AuNCs) ( Figure 8 d,e) [ 36 , 140 , 141 , 142 ]. While such properties and analogous dopants can be typically added to GOFs mainly via their modified cladding layers, in MC fibers, and other biopolymeric fibers, it is possible to make the actual fiber core active and responsive to its environment while still allowing for the further finetuning of the properties via suitable coatings [ 36 , 118 , 120 , 126 , 130 ].…”

To inorganic nanoparticles via nanoclusters: Nonclassical nucleation and growth pathway

“…Various nanoclusters have found many potential applications derived from their unique physiochemical properties such as PL, catalytic activity, and magnetism. PL of nanoclusters is one of the most intriguing properties for applications, because it can be easily tuned and enhanced with various strategies, such as tailoring their size, structure, composition, state‐of‐aggregation, and self‐assembly 99,136–139 . When compared with representative fluorophores, nanoclusters are beneficial in terms of their photostability and biocompatibility, inspiring applications in chemical sensing, bioimaging, optoelectronics, phototherapy, and drug delivery 5 …”

Luminescent Gold Nanocluster‐Methylcellulose Composite Optical Fibers with Low Attenuation Coefficient and High Photostability

“…[ 66 ] Among gold nanoparticles, atomically precise gold nanoclusters (AuNCs) have recently gained considerable attention because of their well‐defined structure, photostability, nontoxicity, and biocompatibility. [ 67–72 ] Their small size, water solubility, and molecule‐like optoelectronic properties allow dispersion in hydrogels. [ 73 ] Gold nanoclusters also possess a high surface‐to‐volume ratio, excellent catalytic effect, and they enable sensing of heavy metal ions.…”

“…[ 73 ] Gold nanoclusters also possess a high surface‐to‐volume ratio, excellent catalytic effect, and they enable sensing of heavy metal ions. [ 67–73 ] Among AuNCs, bovine serum albumin (BSA) coated gold nanoclusters (Au@BSA) and reduced glutathione (GSH) capped gold nanoclusters (Au@GSH) have been explored for sensors, catalysis, bioimaging, and pathogen detection. [ 74–86 ] However, their potential in biopolymer‐based composite fibers for optical amplification and waveguiding is unexplored to date.…”