Introduction
Metal nano-materials are a focus of interest because of their interesting physical and chemical properties, which are ideal building blocks for tailoring nanoscale structures for specific applications. Nowadays these materials can be synthesized and modified with various chemical functional groups which allow them to be conjugated with antibodies, ligands, and drugs, opening a wide range of potential applications in biomedical sciences and engineering. Particularly, effectively controlling the size, shape, architecture, composition, hybrid and microstructure of metal nanomaterials plays a key role on revealing their functions and application potentials.
Fig 1 Various shapes of metal nano-materials
Application
To date, diverse methods have been developed to synthesize metal nanomaterials in a variety of shapes such as particle, rod, wire, polyhedron, dendrite, dimer, belt, star, and cage, etc. These new materials can be utilized in fields of catalysis, electronics, photography, photonics, sensing, imaging, medicine and information storage. There are several examples below:
Au nanomaterials: Au nanoparticles have size-dependent surface plasmon resonance (SPR) property and generally exhibit visible SPR absorption. Gold nanorods, gold nanocage and hollow gold nanospheres own strong near-infrared (NIR) absorption, which are very important for photothermal therapy and bioimaging.
Pt nanomaterials: Pt nanomaterials with high-index facets or complex morphologies or multi-compositions have been proven to exhibit higher electrocatalytic activities toward small molecule oxidation and oxygen reduction reactions than other catalysts.
Ag nanomaterials: Silver nanoparticles with excellent properties such as high electrical conductivity, stability, and low sintering temperatures are being incorporated into products range from photovoltaics to biological and chemical sensors.
Iron oxide nanoparticles: Due to Fe3O4 has ultrafine size, magnetic property, and biocompatibility, superparamagnetic iron oxide nanoparticles have emerged as promising candidates for various biomedical applications, such as enhanced resolution contrast agents for MRI, targeted drug delivery and imaging, gene therapy, stem cell tracking, molecular/cellular tracking and magnetic separation technologies.
