This chapter focuses on the most relevant applications of GNS in life science. The versatility of the GNS functionalization is combined with their optical properties to provide promising and prospective approaches in a variety of biomedical fi elds. Nanosensing assays, thermal treatments, and delivery systems based on GNS are discussed in this chapter.
Keywords SERS-based sensing • Hyperthermia • Photothermal effect • Smart deliveryFunctionalized gold nanoparticles with controlled geometrical and optical properties are the subject of intensive studies and biomedical applications, including genomics, biosensors, immunoassays, clinical chemistry, laser phototherapy of cancer cells and tumors, and delivery platforms. In these fi elds targeted delivery of drugs, DNA, and antigens is coupled to optical bioimaging and the possibility to monitor cells and image details of tissues with the use of state-of-the-art detection systems [ 1 ]. Nonspherical gold nanoparticles are particularly interesting due to their capability to release locally heat with large effi ciency when they are irradiated in the NIR region of the spectrum [ 2 ]. In addition their size and the shape anisotropy essentially determine the position and the amplitude of the NIR-localized surface plasmon resonance [ 3 ]. The shape of the gold nanostars (GNS), in particular, can be tuned from the shape of sea urchin to that of planar, highly regular penta-branched stars [ 4 ]. The NIR-localized surface plasmon resonance of GNS can be consequently tuned in a wide NIR range up to 1250 nm by varying the axial ratio of protruding branches and multiple LSPR band in the NIR can also be obtained [ 4 ]. The possibility to easily decorate the surface of GNS, in combination with their optical properties