Synthesis of water-dispersible photoluminescent silicon nanoparticles and their use in biological fluorescent imaging

Abstract

Water-dispersible silicon nanoparticles (Si-NPs) are desirable for applications in biological techniques. A simplified method to synthesize such particles is reported here. The resulting Si-NPs are water-dispersible and luminescent. Under the excitation of UV light, the Si-NPs emit strong red light with a peak maximum at 606 nm and a quantum yield of 6%. They are highly stable, and remain so over several weeks. Fourier Transform Infrared (FTIR) spectroscopy shows a visible Si–CH2 scissoring vibration mode. Furthermore, the surface chemical bondings were confirmed by X-ray photoelectron spectroscopy (XPS). In the Si2p and C1s core levels, Si–C components are observed. The diameters of the synthesized Si-NPS as measured by atomic force microscope (AFM) are approximately 5 nm. Furthermore, the nanoparticles can be taken up by cultured cells. Fluorescence images of Si-NPs within MCF-7 human breast cancer cells show they are distributed throughout the cell tissue

Soft X‐ray induced oxidation on acrylic acid grafted luminescent silicon quantum dots in ultrahigh vacuum

“…The fourth (IV) distinct high binding energy at about 289.38 eV is characteristic of the carboxylic acid group of the grafted acrylic acid polymer. The presence of this peak, together with published FTIR data confirms the existence of a surface grafted poly-acrylic acids [15,29].…”

“…2 Experimental 2.1 Si-QDs preparation The detailed synthesis method has been described in previous published paper [29]; here we provide a brief description of the sample preparation. Photoluminescent silicon layers were formed by galvanostatic anodization of boron-doped p-Si (100) oriented wafer (10 V cm resistivity, Compart Technology, Peterborough, UK) in a 1:1 v/v solution of 48% aqueous HF and ethanol solution.…”

Synthesis of Diagnostic Silicon Nanoparticles for Targeted Delivery of Thiourea to Epidermal Growth Factor Receptor-Expressing Cancer Cells

“…The first peak is attributed to Si-C confirming the hydrogen on the surface of SiNPs is replaced with thiourea. 34 The second peak at binding energy 102.73 eV is related to Si-O due to partial surface oxidation under the ambient conditions. 42 The third component at 100.91 eV is assigned to Si-Si within silicon core of NPs.…”

“…Thus, top down techniques such as electrochemical etching might be favourable in this regards to provide SiNPs with high purity. 34 In the present study, a thiourea ligand was synthesized followed by hydrosilylation to functionalize SiNPs with this specific functional group. The hydrogen terminated SiNPs were first prepared through the electrochemical etching of porous silicon and later functionalized by thiourea.…”

The Effect of Surface Treatment in a Solution of Polyacrylic Acid on the Photoluminescent Properties of Porous Silicon

“…Тогда, по мнению авторов, непосредственно на поверхности пор будет формироваться слой, обо-гащенный связями Si-C, которые являются ста-бильными во времени и не ухудшают фотолюминес-центные свойства материала [10]. Более того, в работе [12] было показано, что нанокристаллы por−Si, обра-ботанные в акриловой кислоте, обладают устойчивой ФЛ в течение достаточно длительного времени.…”