Structural and optical properties of composite silicon-silver nanoparticles produced by laser ablation technique and potentials for biophotonicsтезисы докладаТезисы
Дата последнего поиска статьи во внешних источниках: 19 июня 2024 г.
Место издания:Lebedev Physical Institute Moscow Moscow
Первая страница:127
Последняя страница:127
Аннотация:Composite silicon-silver (Si/Ag) nanoparticles simultaneously have properties of dielectric and metallic nanoparticles [1,2]. Such nanocomposites (NCs) are promising for diagnostic and therapeutic applications in biophotonics [3] due to relatively high biocompatibility and low toxicity.In our work, to fabricate Si/Ag NCs we applied the technique of laser ablation of monocrystalline silicon in water-ethanol solution containing AgNO3. The irradiation was carried out with laser pulses (1064 nm, 34 ps, 10 mJ) for 60 minutes. The initial amount of the AgNO3 and the ratio of water and ethanol in the aqueous solution were varied to optimize the technology. This relatively simple one-stage technology makes it possible to obtain stable and chemically pure Si/Ag NCs with a required morphology in quantities which are sufficient for further use in biomedical applications.Energy dispersive X-ray spectroscopy confirmed that the Si/Ag NCs contain Si and Ag. Silicon cores about 120 nm in size are decorated with individual Ag nanoclusters ranging in size from 5 to 15 nm according to data of scanning electron microscopy (SEM). A detailed SEM analysis of the formed Si/Ag NCs additionally revealed morphological features of the NCs which depend on the initial amount of AgNO3, the ratio of water and ethanol in the solution, and the pH-factor of a liquid (water, acetic acid, ammonia) where the nanoparticles were placed after fabrication. Spectrophotometric measurements of the Si/Ag NCs suspensions revealed a pronounced maximum of resonant absorption at the wavelength of 435 nm. This absorption peak is explained using the Mie theory by the presence of Ag nanoclusters and the polydisperse size distribution of silicon nanoparticles. The resonant absorption makes it possible to consider the fabricated Si/Ag NCs as promising agents for photohyperthermia because we can increase heating compared to pure silicon nanoparticles at the same mass concentration owing to the Ag inclusions.
