Opportunities and challenges in energy and electron transfer of nanocluster based hybrid materials and their sensing applications.

This feature article highlights the recent advances of luminescent metal nanoclusters (MNCs) for their potential applications in healthcare and energy-related materials because of their high photosensitivity, thermal stability, low toxicity, and biocompatibility. Current studies reveal that metal cluster based hybrid systems could pave the way for energy harvesting and sensing applications. To begin with, we illustrate general synthesis methodologies for atomically precise metal nanoclusters and discuss the origin of photoluminescence properties and the electronic transitions of nanoclusters. Successively, we discuss the energy transfer and electron transfer processes in metal cluster based hybrid systems with CdTe QDs, carbon dots (C-dots), functionalized DNA and graphene oxide. Finally, we address the potential advantages of metal clusters and their hybrid systems as an optical probe for the selective detection of toxic metal ions. A tentative outlook on fundamental challenges and future opportunities of this research field is highlighted.