CC BY
15LM-P-3
Laser fragmentation of silicon microparticles in liquids
V. Nesterov1, D. Shuleiko1, A. Kolchin1, D. Presnov1, S. Zabotnov1, L. Golovan1, P. Kashkarov1,
E. Sergeeva21, D. Kurakina2, M. Kirillin2
1-Lomonosov Moscow State University, Faculty of Physics, 1/2 Leninskie Gory, Moscow, 119991, Russia 2- Institute of Applied Physics RAS, 46 Uljanov street, Nizhny Novgorod, 603950, Russia
E-mail: [email protected]
Nowadays, silicon nanoparticles (SiNPs) formed by laser technologies have potential in diagnostic and therapeutic applications in biomedicine due to their high biocompatibility and biodegradability, as well as low level toxicity [1-3].
To fabricate SiNPs we propose using the technique of laser fragmentation of silicon microparticles (16 ^m) in water or ethanol exposed to laser pulses (1064 nm, 34 ps). The initial concentrations of the silicon micropowder and irradiation time were varied to optimize the technique. This relatively simple technology allows producing stable and chemically pure SiNPs in quantities large enough for further use in biomedical applications [3]. We have focused our attention on the study of relationships between structural properties of the fabricated nanoparticles and modes of their formation. Additionally, elastic scattering and absorption of the SiNPs suspensions were analyzed.
The analysis of scanning electron microscopy images revealed that the formed Si-NPs have a relatively smooth surface and a shape which is close to spherical. Scanning electron microscopy of the formed SiNPs and dynamic light scattering in their suspensions revealed dependences of the nanoparticles size (the mean size varied from 110 to 340 nm) on the buffer liquid used, initial concentration of silicon micropowder in suspension, and the laser pulses exposure time. The fabricated SiNPs demonstrates low agglomeration, while Raman spectra of the SiNPs evidence their high crystallinity. Spectrophotometry measurements of the SiNPs suspensions revealed that the scattering coefficient exceeds 2 mm-1 in the spectral range of 400 - 1000 nm, while the absorption coefficient is less by an order of magnitude in this region. The scattering spectrum demonstrates nonmonotonic behavior with a maximum in the red region, which is explained by a Mie resonance.
The obtained results show that SiNPs fabricated by laser fragmentation of silicon micropowder in a liquid have a potential for contrasting biological tissues and their phantoms in optical imaging modalities, such as optical coherence tomography or fluorescence imaging.
This work was supported by the Russian Science Foundation (project № 19-12-00192).
[1] S.V. Zabotnov, A.V. Skobelkina, E.A. Sergeeva, et al., Sensors, 20, 4874, (2020).
[2] S. Besner, A.V. Kabashin, F. Winnik, et al., Appl. Phys., vol. 93, 955-959, (2008).
[3] M.B. Gongalsky, L.A. Osminkina, A. Pereira, et al., Sci. Rep., 6, pp. 24732, (2016).
