Metal nanoclusters: New fluorescent probes for sensors and bioimaging

•Fluorescent metal nanoclusters have been developed as a new class of fluorophores with excellent properties.•New developments in the controllable synthesis and properties of metal nanoclusters are introduced.•The applications of metal nanoclusters in sensors and bioimaging are summarized.•Future challenges and prospects of the development of metal nanoclusters are concluded.

SummaryFluorescent metal nanoclusters (NCs) as a new class of fluorophores have attracted more and more attention due to their unique electronic structures and the subsequent unusual physical and chemical properties. The size of metal NCs approaches the Fermi wavelength of electrons, between metal atoms and nanoparticles, resulting in molecule-like properties including discrete energy levels, size-dependent fluorescence, good photostability and biocompatibility. These excellent properties make them ideal fluorescent probes for biological application. Up to now, significant efforts have been devoted to the synthesis, property and application studies of gold and silver NCs. Recently, a growing number of studies on copper and other metal clusters have also been reported. In this review article, we focus on summarizing recent advances in controllable synthesis strategies, chemical and optical properties, and sensing and imaging applications of metal NCs (mainly including Au, Ag, Cu, etc.). Finally, we conclude with a look at the future challenges and prospects of the future development of metal NCs.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (80 K)Download as PowerPoint slide