" Nanoplasmonics and surface enhanced spectroscopy "

Simple size-controlled synthesis of Au nanoparticles
Kapush O.A.1, Dzhagan V.M.1, Yemets A.I.2, Plokhovska S.H.2, Pirko Ya.V.2, Skoryk M.A.3, Yukhymchuk V.O.1, Valakh M.Ya.1

1 V. Lashkaryov Institute of Semiconductor Physics National Academy of Sciences of Ukraine. 45 Nauky Av., 03028 Kyiv, Ukraine. 
E-mail: dzhagan@isp.kiev.ua
2 Institute of Food Biotechnology and Genomics, National Academy of Sciences of Ukraine, 2a Osypovskoho Str., 04123 Kyiv, Ukraine.
3 G.V. Kurdyumov Institute for Metal Physics, National Academy of Sciences of Ukraine, 36 Academician Vernadsky Blrd, 03142 Kyiv, Ukraine

Synthesis and investigation of gold and silver nanoparticles (NPs) properties is an area of intense investigations motivated by their wide range of applications. Most of the applications are based on the effect of localized surface plasmon resonance (LSPR), a collective excitation of free charge carriers by the light of a specific wavelength (usually laser). Both the absorption lineshape and the scattering intensity can be tuned by controlling the particle size, shape, and the local refractive index near the particle surface. 
Here a new and straightforward approach to the synthesis of low-temperature Au NPs in dimethyl sulfoxide (DMSO) is described. According to the scanning electron microscopy data (Fig.1, inset), the obtained NPs are rather monodisperse quasi-spherical with the average size ~ 10 nm. The optical absorption spectrum of these NPs exhibits a characteristic plasmon band centered at about 550 nm, which
 Fig. 1. Optical absorption spectrum of Au NPs solution (inset: SEM image).	is in qualitative agreement with the NP size. The high structural perfection, the optical properties, along  with the easy synthesis process, makes these Au NPs a promising candidate for various applications ranging from electronics to energy and to biology.

This work was partially funded by NRFU (grant # 2020.02-0204) for KOA, DVM, PSH, PYV, YVO and by NAS of Ukraine (#59/КТ-20-05) for DVM, YVO, VMY.