Sona Nanotech Inc C.SONA

This is why SONA is different

[Findingmoney]

From the SONA site
Gold nanorods (GNRs) are small particles whose surface plasmon resonance (SPR) frequencies can be altered as a function of the length and width, giving these anisotropic particles optical properties useful in a host of applications (1,2). GNRs have been used in a number of biomedical applications, including as contrast agents for optical biomedical imaging and for their hyperthermal effects. One of the major barriers in the application of GNR-based materials, especially for in-vivo applications such as hyperthermal cancer treatment, is the efficient exchange and removal of cetyltrimethylammonium bromide (CTAB), the surfactant used exclusively in the large scale synthesis of GNRs. CTAB is a cytotoxic, cationic surfactant with an extremely low critical micelle concentration (3-5). Its function in the synthesis of the gold nanorods is still a matter of debate, but it is generally thought that the CTAB forms a strongly adsorbed bilayer around the surface of the growing gold particle (6-8).

The concentration of CTAB that is most often used in the synthesis of gold nanorods is 0.10 M or 100 times its critical micelle concentration, meaning a significant amount of CTAB remains in the bulk of the solution after the GNRs are made, which serves to stabilize the GNRs (prevents them from selfaggregating in solution)(6). The CTAB surfactant, so critical for GNR synthesis, is a significant impediment to in-vivo applications. A number of methods have been used to “remove” or partially exchange the CTAB including frequent solvent washing, treatments with surface active materials such as PEGylated thiols or other polymers (9-11). However, during surface exchange CTAB-coated GNR dispersions are destabilized, which results in particle aggregation and low recovery yields of GNRs. In addition, these surface modified GNRs are often contaminated with residual CTAB (9).