Tetraethyl decamethylenediphosphonate, 98%

Herein, magnetic mesoporous N-doped silica nanospheres decorated by CuO nanoparticles (M-MNS/CuO) were prepared and used for the green and efficient synthesis of some [3.3.3] propellane indeno[1,2-b] indole derivatives. In order to prepare N-doped silica nanoparticles, tetraethyl orthosilicate (TEOS) was used as the silica source, and diethanolamine (DEA) as a nitrogen precursor. Immobilization of CuO nanoparticles on the mesoporous N-doped silica nanosphere surfaces increases the surface area of catalyst and provides Lewis acidic sites in addition to nitrogen atoms as active basic sites. The presence of nitrogen atoms and copper oxide nanoparticles in the catalyst structure, give dual acidic and basic properties. The synthesized catalyst was characterized by FESEM, EDS, HRTEM, XRD, VSM, FTIR, and BET techniques which proved its magnetic core shell structure.

Antimicrobial coating of polyethylene endotracheal tubes (PE ETTs) has proven to be an effective method to prevent endoluminal biofilm formation. A transparent silicon-modified antimicrobial PE ETT was obtained by coating PE with a SiO2 /γ-methacryloxypropyl trimethoxy silane (KH-570)/methyltriethoxysilane (MTES)/Ag-SiO2 solution prepared by chemically mixing Ag-SiO2 with SiO2 /KH-570/MTES in solution via a dip-coating method, with tetraethyl orthosilicate (TEOS) as the inorganic silicon source, followed by drying. All the films were characterized by various techniques, including the pencil hardness test, infrared spectroscopy, scanning electron microscopy, UV-vis analysis, and inductively coupled plasma mass spectrometry (ICP-MS). The results indicated that the TEOS/KH-570/MTES/Ag-SiO2 (15:6:1:0.6-1.0) films, which exhibited simple in-solution film formation on PE ETTs, had a homogeneous morphology, high transmittance above 87%, high hardness of 5H and strong adhesion to the tubes. The concentration of Ag+ ion dissolved out from the antibacterial coating is very low in ICP-MS results. The antibacterial test results show that the antibacterial coatings have excellent antibacterial property with antibacterial ratio up to 93.5% when Ag-SiO2 content is 2.6%. In pyrogen test and hemolytic test, the body temperature of rabbits rise 0.03°c for 3 h after inserting antibacterial PE ETT, and the hemolytic ratio is 0.7512%, which conform to the requirements of biomedical material. The results preliminarily proved that the antibacterial materials could be a good candidate of medical catheter material application or medical device surface coating materials. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 91-98, 2017.

Water-dispersed fluorescent silicon nanodots (SiNDs) were synthesized by a one-pot hydrothermal method starting from tetraethyl orthosilicate (TEOS) as silicon source and trisodium citrate as reducing reagent. The method is simple and convenient. The SiNDs, with excitation/emission peaks at 347/440 nm and with fluorescence quantum yield of 18% are shown to be viable fluorescent probes for picric acid (PA). The SiNDs strongly bind PA, and their blue fluorescence is quenched. The distance between the donor and acceptor (R0 value) is calculated from fluorescence data to be 2.1 nm. A fluorometric method was worked out that has a linear response in the 8 nM to 50 μM PA concentration range and a 0.92 nM limit of detection. The method has a fast response (2 min) and is well selective over other nitroaromatic compounds and metal ions. The average recoveries from spiked lake water samples ranged between 98.4 and 100.8%. Graphical abstract Water-dispersed fluorescent silicon nanodots (SiNDs) are synthesized using tetraethyl orthosilicate (TEOS) and trisodium citrate. Based on spectral overlap of fluorescent spectrum of SiNDs and absorption spectrum of picric acid (PA), fluorometric determination of PA at concentrations as low as 0.92 nM is achieved.