Quats Stabilized Gold Nanospheres for Efficient Ligand Exchange Procedure

Abstract In present work, fine spherical shaped gold nanoparticles are prepared by using a new type of quaternary ammonium cationic surfactant (quats) i.e. didecyldimethylammonium chloride (DDAC) following one step room temperature method. Optical characterization and crystal symmetry has been observed through UV-Vis spectroscopy and XRD analysis, respectively. DDAC coated gold nanospheres (GNSs) are also analysed by using FTIR technique in order to observe binding of the ligand onto the surface of gold. Ligand weight loss has been determined by using TGA technique. Particle size has been examined by using TEM and DLS techniques both. Stability of DDAC coated gold nanoparticles are also examined by using Zeta-potential. A comparison of stabilities of different quats stabilized gold nanoparticles (GNPs) has also been discussed in the present work. Unlike usual CTAB and CTAC ligands, the low binding affinity of DDAC to the gold surface may be more efficient for ligand-exchange procedure. A sharp and fine peak of PL spectrum at around 600 nm has been noticed for these GNSs. These luminescent, monodispersed and fine spherical shaped GNPs of size less than 40 nm can be valuable in plasmonics and single molecular tracking for further characterizations.