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Updated: Feb 7, 2026

Synthesis of Near-Infrared Emitting Gold Nanoclusters for Biological Applications
Published on: March 22, 2020
Highly stable, luminescent gold nanocluster assemblies driven by depletion and covalent linker interactions
Arun Mukhopadhyay1,2, Diptibala Pradhan1,2, Anant Kumar Singh3
1Materials Chemistry and Interfacial Engineering Department, CSIR-Institute of Minerals and Materials Technology (IMMT), Bhubaneswar, Odisha 751013, India. ngoswami.immt@csir.res.in.
Abstract:
Supramolecular assembly of ultra-small, metal nanoclusters (NCs) offers a versatile platform to modulate their environment-dependent physicochemical properties; however, achieving structural control together with high thermodynamic stability remains challenging due to weak and dynamic noncovalent interactions. Herein, we present a straightforward strategy to construct highly stable assemblies of atomically precise Au22(SG)18 NCs by coupling depletion attraction forces with a tetrathiol-containing small-molecule crosslinker, which imparts covalent linkage and thermodynamic robustness against harsh environments such as pH, solvent, probe sonication, and high temperature. The resulting assemblies also exhibit enhanced photoluminescence via an aggregation-induced emission mechanism, and the approach extends to non-precise Au NCs, demonstrating its broad applicability for controlled assembly of metal NCs.
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