Optical methods of silicon nanoparticle diagnostics for applications in biomedicine

Abstract

The method of Raman scattering spectroscopy was used to study various silicon nanostructures (nanowires, mesoporous nanoparticles, crystalline and laser-ablated nanoparticles) dispersed in aqueous medium. The obtained results indicate different dissolution rate for silicon nanoparticles of different sizes and morphology in water that can be used for their potential biomedical applications.

Laser-Ablative Synthesis of Silicon–Iron Composite Nanoparticles for Theranostic Applications

“…One can see that the Raman signal from the target only has peaks associated with the crystalline Si lattice, while other phases related to iron silicide or iron oxides cannot be detected. On the other hand, the presented Raman spectrum from Si-Fe NPs has more features, as it contains a sharp peak at 516 cm −1 and a broad band centered at 490 cm −1 , which are attributed to the Si nanocrystalline and amorphous Si phases, respectively [37]. Note that the recorded shift in Raman peak of crystalline Si from 520 cm −1 to 516 cm −1 (Figure 3b) for the spectra obtained from the ablation target and Si-Fe NPs, respectively, indicates that Si nanocrystals have sizes of a few nanometers, while the size of NPs is tens of nanometers.…”

Measurement of Silicon Nanoparticles Temperature by Raman Spectroscopy

“…Silicon nanoparticles (Si NPs), including NPs of crystalline and porous silicon, are widely researched for biomedicine applications, in particular, as active elements of biosensors and as part of new drugs for theranostics (simultaneous diagnosis and therapy) of oncological and other socially significant diseases [1][2][3][4][5][6]. If the size of crystalline NPs is less than 10 nm, they exhibit photoluminescence in the biological transparency window (650-850 nm), which can be used for their visualization in cells and tissues [7][8][9][10][11]. The large Si nanoparticles (more than 10 nm) are in turn capable of providing nonlinear biovisualization mechanisms, such as two-photon luminescence and second harmonic generation, the combination of which makes it possible to effectively track both individual silicon NPs and their aggregation in different parts of the cell, while the resolution of such approach is sufficient to obtain 3Dimages [12].…”