Water-soluble Silicon Nanoparticles Research Articles

Water Soluble Silicon Nanoparticles as a Fluorescent Probe for Highly Sensitive Detection of Rutin.

In this work, water-soluble fluorescent silicon nanoparticles (SiNPs) were prepared by one-pot hydrothermal method using 3-(2-aminoethylamino)propyldimethoxymethylsilane (AEAPDMMS) as a silicon source and amidol as a reducing agent. The prepared SiNPs showed bright green fluorescence, excellent stability against photobleaching, salt tolerance, temperature stability, and good water solubility. Due to the internal filtration effect (IFE), rutin could selectively quench the fluorescence of the SiNPs. Based on such phenomena, a highly sensitive fluorescence method was established for rutin detection. The linear range and limit of detection (LOD) were 0.05–400 μM and 15.2 nM, respectively. This method was successfully applied to detect rutin in the samples of rutin tablets, Sophora japonica, fry Sophora japonica, and S. japonica carbon with satisfactory recovery.

Determination of Fe(Ⅲ) ion and cellular bioimaging based on a novel photoluminescent silicon nanoparticles

The determination approaches of Fe (Ⅲ) in biological samples were developed by a novel water-soluble silicon nanoparticles (SiNPs). The SiNPs were synthesized by a facile microwave-assisted method, and simultaneously featured strong blue fluorescence (photoluminescence quantum yield: 25.2%), long lifetime (~13.29 ns) and good photo-stability. The fluorescence intensities of SiNPs were gradually quenched with Fe (Ⅲ) concentration increasing from 2.0 to 50 μmol/L. The detection limit of the established method was 0.56 μmol/L and the precision for eleven replicate detections of 20 μmol/L Fe (Ⅲ) was 3.2% (relative standard deviation, RSD). The spiked recoveries were 99.0%–104.5%. Results of the lifetime decay and cyclic voltammetry (CV) evidenced that the electron transfer was responsible for the fluorescence quenching mechanism of SiNPs and Fe (Ⅲ). Moreover, the SiNPs were successfully applied in the determination of Fe(Ⅲ) in different environmental waters and human serum. Finally, the resulting SiNPs exhibited the green fluorescence in HeLa cells as the optical probe.

Synthesis of fluorescent and water-soluble silicon nanoparticles with a high pH response and its application to pH measurement and gastric parietal cell imaging

In this work, an effective, simple and facile approach was applied to prepare Si NPs, which emitted yellow fluorescence and were used for pH measurement and fluorescence imaging.

Highly selective and sensitive detection of catechol by one step synthesized highly fluorescent and water-soluble silicon nanoparticles

Because the chemical properties and structures of catechol and its analogues (hydroquinone and resorcinol) are similar, it still is a great challenge to detect catechol from other hydroxybenzene isomers with high accuracy and reliability. Herein, a selective and sensitive method based on the water soluble silicon nanoparticles (Si NPs) was established for catechol detection, and to the best of our knowledge, this is the first time using Si NPs for catechol measurement. The synthesis of Si NPs was very cheap and simple, no time-consuming, and no need for high temperature processing, or special instrument. The as-synthesized Si NPs, with high salt and temperature stabilities emitted yellow-green fluorescence (540 nm). A good linear relationship was observed from 0.06 to 40 μM and the limit of detection (based on 3s/k) was calculated as 20 nM, and the sensor displayed a significant selectivity toward catechol over other dihydroxybenzene isomers. Moreover, the Si NPs were applied in tap water, human serum samples and Yellow River water for catechol measurement.

Preparation and oxygen sensing properties of water-soluble silicon nanoparticles assembled SBA-15

A kind of optical oxygen sensing material was obtained in a simple and low-cost method via assembling water-soluble silicon nanoparticles (Si NPs) into the well-ordered channel of SBA-15. The system we had developed showed high selectivity and sensitivity to oxygen which was attributed to large pore sizes and high surface-to-volume ratios of SBA-15. The fluorescence intensities of the samples were recorded under different oxygen volume fractions. By analyzing experimental data, we found the samples had little response to carbon dioxide. The fluorescence intensity decreased prominently as oxygen volume fractions transformed from 0 to 100%. These results indicated that the SBA-15/Si NPs composites had superior properties for oxygen sensing and would provide broad application prospects in oxygen sensing or catalyst.

Hydrothermal synthesis of fluorescent silicon nanoparticles using maleic acid as surface-stabilizing ligands

Water-soluble silicon nanoparticles (SiNPs) have been synthesized with photoluminescence quantum yield more than 32% via a hydrothermal treatment of 3-aminopropyltriethoxysilane as silicon sources and maleic acid (MA) as surface-stabilizing ligands. Prepared SiNPs showed the presence of carboxylic acid groups through the incorporation of MA. The presence of 48.8 and 51.2% of Si–Si and Si–O binding was observed in the resulting carboxylic acid-functionalized SiNPs (COOH-SiNPs). As revealed by the fluorescence lifetime images, COOH-SiNPs possesses several fluorophores mainly composed of above Si–Si binding inside of single particle, which explains the excitation-dependent fluorescence emission behavior of COOH-SiNPs. Also, the presence of oxides mainly composed of Si–O binding and MA on the surface of COOH-SiNPs provides long-term stability for both fluorescence and dispersion. The potential use of COOH-SiNPs as fluorescence bioimaging agents for cellular media has been demonstrated. COOH-SiNPs showed excellent cell viability more than 91% for both MDAMB and MDCK cells even in 1,000 ppm concentration, and multicolor fluorescence imaging (blue, green, and red) of MDAMB cells was successfully accomplished with different excitation wavelengths.

One-Pot Synthesis of Fluorescent Silicon Nanoparticles for Sensitive and Selective Determination of 2,4,6-Trinitrophenol in Aqueous Solution.

Because 2,4,6-trinitrophenol (TNP) and its analogues such as 2,4,6-trinitrotoluene (TNT) possess similar chemical structures and properties, the reliable and accurate detection of TNP from its analogues still remains a challenging task. In the present work, a selective and sensitive method based on the water-soluble silicon nanoparticles (SiNPs) for the determination of TNP was established. The SiNPs with good thermostability and excellent antiphotobleaching capability were prepared via a simple one-pot method. Compared with the synthesized time of other nanomaterials with respect to the detection of TNP, this method avoided a multistep and time-consuming synthesis procedure. Significantly, the fluorescence of the SiNPs could be remarkably quenched by TNP via an inner filter effect. A wide linear range was obtained from 0.02 to 120 μg/mL with a limit of detection of 6.7 ng/mL. The method displayed excellent selectivity toward TNP over other nitroaromatic explosives. The proposed fluorescent method was successfully applied to the analysis of TNP. Moreover, a straightforward and convenient fluorescent filter paper sensor was developed for the detection of TNP, providing a valuable platform for TNP sensing in public safety and security.

One-Step Synthesis of Water-Dispersible and Biocompatible Silicon Nanoparticles for Selective Heparin Sensing and Cell Imaging.

A sensitive and selective fluorescence "turn-off" sensor to detect heparin using water-soluble silicon nanoparticles (Si NPs) was developed for the first time. The Si NPs were synthesized by a simple one-step procedure, which did not need high-temperature and complex modification. The as-prepared Si NPs featured strong fluorescence, favorable biocompatibility, and robust photo- and pH stability. Significantly, the Si NPs were induced to assemble or aggregate via hydrogen bonding, which resulted in the fluorescence of Si NPs quenched. Under the optimized conditions, the linear range was obtained from 0.02 to 2.0 μg/mL, with a limit of detection of 18 ng/mL (equal to 0.004 U/mL). It was lower than the proper therapeutic level of heparin during cardiovascular surgery and long-term therapy. This proposed method was relatively free of interference from heparin analogues, which commonly existed in heparin samples and could possibly affect heparin detection. Moreover, it did not need to introduce any control medium. As expected, the method was successfully applied to detect heparin in human serum samples with satisfactory recovery ranging from 98.8 to 102.5%. The Si NPs were superbly suitable for cell imaging owing to the negligible cytotoxicity and excellent biocompatibility.

Synthesis of superbright water-soluble silicon nanoparticles and their application for dopamine detection

Synthesis of superbright water-soluble silicon nanoparticles and their application for dopamine detection

Silicon Nanoparticles: One‐Step Synthesis of Superbright Water‐Soluble Silicon Nanoparticles with Photoluminescence Quantum Yield Exceeding 80% (Adv. Mater. Interfaces 16/2015)

A commercially available amine-containing silane molecule, N-[3-(trimethoxysilyl)propyl]ethylenediamine (DAMO) is introduced in article 1500360 by F. G. Wu, Z. Chen, and co-workers. Superbright water-soluble silicon nanoparticles (SiNPs) are prepared with a photoluminescence quantum yield (PLQY) of 82.4% via a one-pot microwave-assisted method. To the best of the authors' knowledge, this is the highest PLQY value ever reported for water-soluble fluorescent SiNPs.

Highly sensitive and selective detection of dopamine using one-pot synthesized highly photoluminescent silicon nanoparticles.

A simple and highly efficient method for dopamine (DA) detection using water-soluble silicon nanoparticles (SiNPs) was reported. The SiNPs with a high quantum yield of 23.6% were synthesized by using a one-pot microwave-assisted method. The fluorescence quenching capability of a variety of molecules on the synthesized SiNPs has been tested; only DA molecules were found to be able to quench the fluorescence of these SiNPs effectively. Therefore, such a quenching effect can be used to selectively detect DA. All other molecules tested have little interference with the dopamine detection, including ascorbic acid, which commonly exists in cells and can possibly affect the dopamine detection. The ratio of the fluorescence intensity difference between the quenched and unquenched cases versus the fluorescence intensity without quenching (ΔI/I) was observed to be linearly proportional to the DA analyte concentration in the range from 0.005 to 10.0 μM, with a detection limit of 0.3 nM (S/N = 3). To the best of our knowledge, this is the lowest limit for DA detection reported so far. The mechanism of fluorescence quenching is attributed to the energy transfer from the SiNPs to the oxidized dopamine molecules through Förster resonance energy transfer. The reported method of SiNP synthesis is very simple and cheap, making the above sensitive and selective DA detection approach using SiNPs practical for many applications.

Water-soluble PEGylated silicon nanoparticles and their assembly into swellable nanoparticle aggregates

Water-soluble silicon nanoparticles were synthesized by grafting PEG polymers onto function- alized silicon nanoparticles with distal alkyne or azide moieties. The surface-functionalized silicon nanopar- ticles were produced in one step from the reactive high-energy ball milling (RHEBM) of silicon wafers with a mixture of either 5-chloro-1-pentyne in 1-pen- tyne or 1,7 octadiyne in 1-hexyne to afford air and water-stable chloroalkyl or alkynyl-terminated nano- particles, respectively. Nanoparticles with the x- chloroalkyl substituents were easily converted to x- azidoalkyl groups through the reaction of the Si nanoparticles with sodium azide in DMF. The azido- terminated nanoparticles were then grafted with mono-alkynyl-PEG polymers using a copper- catalyzed alkyne-azide cycloaddition (CuAAC) reac- tion to afford core-shell silicon nanoparticles with a covalently attached PEG shell. Covalently linked Si nanoparticle clusters were synthesized via the CuAAC ''click'' reaction of functional Si NPs with a,x- functional PEG polymers of various lengths. Dynamic light scattering studies show that the flexible globular nanoparticle aggregates undergo a solvent-dependent change in volume (ethanol ( dichloromethane ( tol- uene) similar in behavior to hydrogel nanocomposites.

Using liquid and solid state NMR and photoluminescence to study the synthesis and solubility properties of amine capped silicon nanoparticles

Water soluble silicon nanoparticles were prepared by the reaction of bromine terminated silicon nanoparticles with 3-(dimethylamino)propyl lithium and characterized with liquid and solid state nuclear magnetic resonance (NMR) and photoluminescence (PL) spectroscopies. The surface site dependent 29Si chemical shifts and the nuclear spin relaxation rates from an assortment of 1H– 29Si heteronuclear solid state NMR experiments for the amine coated reaction product are consistent with both the 1H and 13C liquid state NMR results and routine transmission electron microscopy, ultra-violet/visible, and Fourier transform infrared measurements. PL was used to demonstrate the pH dependent solubility properties of the amine passivated silicon nanoparticles.