Synthesis and characterization of silicon nanoparticles in a cost-effective method

Silicon nanoparticles (Si NPs) have potential applications for cell imaging due to negligible cytotoxicity and excellent biocompatibility. In this study, Si NPs were synthesized in a simple step that does not require high temperatures and complex modifications. In the synthesis, (3-aminopropyl)triethoxysilane (APTES) was used as the silicon source and ascorbic acid (AA) was used as the reductant. A series of synthesis was carried out by changing the synthesis temperature and time, APTES amount and AA amount.Synthesized Si NPs were characterized by ultraviolet-visible spectrometry (UV-Visible), fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and photoluminescence spectroscopy (PL) devices.FT-IR results showed that the resulting Si NPs had a large amount of amino groups. The band gap values obtained as a result of McLeans analysis of the samples vary between 3.20 eV and 5.10 eV. When more AA reducing agent was used, the band gap decreased, and when the amount of APTES molecules was increased, more than one band gap was obtained and enlarged. The samples showed emission at 520 nm, and unlike the literature, the emission intensity of the samples increased over time and shifted to the 480 nm wavelength. In the samples for which TEM photographs could be taken, the average particle sizes varied between 8,508 nm and 11,884 nm, and the particle size decreased when AA reducer was used extensively and increased when APTES was used frequently. It was observed that the samples kept for approximately 3 months showed better luminescence under the UV lamp. It is thought that unreduced APTES molecules react among themselves over time, increasing the size of silicon particles and increasing luminescence. Since the synthesized Si NPs have amine groups on their surfaces and have colloidal stability, their interactions with biomolecules are important.