Introduction
Nanoprisms, also referred to as nanoplates, are a class of two-dimensional structures with parallel top and bottom and a nanoscale thickness. As we known, nanoparticles’ shape is an important parameter, controlling their many physical chemical properties. Nanoprisms have attracted intensive attention because of their strong shape-dependent optical properties. Up to date, a variety of synthetic strategies, such as photochemical, thermal and biological routes, have been explored to prepare bulk quantities of metal nanoprisms.
Fig 1 TEM images of Au Nanoprisms
(Z. Guo et al. / Journal of Colloid and Interface Science 2010, 348, 29-36)
Compared with the conventional nanospheroids, nanoprisms exhibit a large red shift of surface plasmon resonance (SPR). Their unique optical properties offer potential for diverse applications such as surface-enhanced Raman, fluorescence spectroscopies, molecular sensing, biomedical diagnostics, tomography agents, cancer therapy, photonic circuits and optical waveguides.
Applications
Gold Nanoprisms: Gold nanoprisms can be applied in biosensing based on the changes of the SPR band induced by the specific antibody-antigen recognition events. In addition, colloidal gold nanoprisms, with extremely flat surface and strong NIR absorption, could also find practical applications for drug delivery and hyperthermia treatment of tumors in vivo.
Silver Nanoprisms: Silver Nanoprisms can be used to modify the blinking behavior of quantum dots. In the presence of Ag nanoprisms, the fluorescence time trace (blue curve) exhibits continuous fluctuation without completely no long-lived dark periods. In this way, the fluorescence quantum yield can be enhanced and fluorescence lift time can be shortened. With improved performance, such a coupled complex consisted of Ag nanoprisms and quantum dots could be used as a fluorescent marker in life science applications.
