Gold nanoclusters: Photophysical properties and photocatalytic applications

Abstract

Atomically precise gold nanoclusters (Au NCs) have high specific surface area and abundant unsaturated active sites. Traditionally, Au NCs are employed as thermocatalysts for multielectron transfer redox catalysis. Meanwhile, Au NCs also exhibit discrete energy levels, tunable photophysical and electrochemical properties, including visible to near infrared absorption, microsecond long-lived excited-state lifetime, and redox chemistry. In recent years, Au NCs are increasingly employed as visible to near infrared photocatalysts for their high photocatalytic activity and unique selectivity. This review focuses on the photophysical properties of a variety of Au NCs and their employment as photocatalysts in photocatalytic reactions and related applications including solar energy conversion and photodynamic therapies.

The Role of the Amino Acid Molecular Characteristics on the Formation of Fluorescent Gold‐ and Silver‐Based Nanoclusters

“…0.3 ns) are almost the same in every sample. Since gold and silver have very similar chemical structures, therefore the photons originates from the metal‐to‐metal charge transfer in the formed zero valance stated cluster cores (Phe‐Au, Gln‐Au and Gln‐Ag) or the aurophilic (Au⋅⋅⋅Au)/argentophilic (Ag⋅⋅⋅Ag) interactions of the metal complexes in the case of Arg‐Au, Arg‐Ag and Gln‐Ag, respectively [20,23,24] . In contrast, both τ 1 and τ 2 are ligand‐dependent properties, which show different contribution percentages depending on the selected amino acids and belong to the LMCT and LMMCT, respectively.…”

“…the formed zero valance stated cluster cores (Phe-Au, Gln-Au and Gln-Ag) or the aurophilic (Au•••Au)/argentophilic (Ag•••Ag) interactions of the metal complexes in the case of Arg-Au, Arg-Ag and Gln-Ag, respectively. [20,23,24] In contrast, both τ 1 and τ 2 are ligand-dependent properties, which show different contribution percentages depending on the selected amino acids and belong to the LMCT and LMMCT, respectively.…”

“…The lifetimes in the case of the studied samples show an increasing trend according to the order Phe < Arg < Gln. As it is wellknown that beside the oxidation state of the central metal atoms, the chemical nature of the surface ligand has also a Chemistry-A European Journal great influence on the average fluorescence lifetime, [20,21] which can provide approximate information about the structure of the prepared systems. Despite the similar atomic numbers in the metal cores, the average fluorescence lifetimes show different values depending on the chosen amino acid.…”

Biomolecule-protected gold nanoclusters: synthesis and biomedical applications

“…Composed of a few to several hundred gold atoms, AuNCs are intermediate states of matter between isolated molecules and large nanoparticles and exhibit molecular-like properties. 5,6 AuNCs consist of a metallic core containing a small number of gold atoms and a ligand surrounding the protective core. 7 The size of AuNCs is typically less than 2 nm.…”

Unveiling the Long-Lived Emission of Copper Nanoclusters Embedded in a Protein Scaffold

“…A large Stokes shift, a two-photon absorption cross section, high photostability, good biocompatibility, and a tunable emission wavelength are some of the interesting photophysical properties that make them superior to traditional fluorescent nanomaterials. 8,9 However, the excited state dynamics of these nanoclusters are still debatable.…”