Silver Nanorods Stabilised By Gemini Surfactant As Components For Nanosensing Applications

Silver nanoparticles (AgNPs) have been used in numerous of biomedical applications, i.e. as vectors in gene treatment, in cancer diagnostics and therapy (theranostics). AgNPs because of their properties, may have ability to integrate with oligopeptide template, that can be used as potential intelligent dressing. Properties of silver nanoparticles depend on their shape and size that can be adjusted during the synthesis. In order to increase monodispersity of the particles, sodium borohydride (NaBH4) was used as a reducing agent and hexadecyl-trimethyl-ammonium bromide (CTAB) as a capping agent. Minimal toxicity and large surface area may be obtained by the use of dimeric-gemini surfactants which induce production of rod-shaped particles and allow attachment of ligands such as nucleic acids and proteins. Silver nanorods were prepared by seed-mediated growth method which is divided into two stages: nucleation and growth. The nucleation step depends on the reduction of metal ions which leads to seeds formation. The growth of seeds occurs in the second step where they are placed in growth solution. The role of CTAB is to control the direction of growth and form the shape of particles. To prevent aggregation induced by surface modification and obtain desired shape oligomeric surfactants were used alongside with CTAB. The synthesized silver rod-shaped nanoparticles in the presence of oligomeric surfactants were characterized by small angle X-ray scattering (SAXS), nuclear magnetic resonance (NMR) diffusometry and microscopic techniques such as transmission electron microscopy (TEM) and atomic force microscopy (AFM). As a result, we examined the impact of the surfactants on homogeneity of AgNPs and its role in modification of the surface for biomedical application. This research project was supported by program Best of the Best (Najlepsi z Najlepszych) 4.0 from Ministry of Science and Higher Education (Poland).