Optical, structural and antibacterial properties of silver nanoparticles and DNA-templated silver nanoclusters

Silver nanoparticles (AgNPs) are increasingly considered for biomedical applications as drug-delivery carriers, imaging probes and antibacterial agents. Silver nanoclusters (AgNCs) represent another subclass of nanoscale silver. AgNCs are a promising tool for nanomedicine due to their small size, structural homogeneity, antibacterial activity and fluorescence, which arises from their molecule-like electron configurations. The template-assisted synthesis of AgNCs relies on organic molecules that act as polydentate ligands. In particular, single-stranded nucleic acids reproducibly scaffold AgNCs to provide fluorescent, biocompatible materials that are incorporable in other formulations. This mini review outlines the design and characterization of AgNPs and DNA-templated AgNCs, discusses factors that affect their physicochemical and biological properties, and highlights applications of these materials as antibacterial agents and biosensors.