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Silylated cellulose has been successfully synthesized using TEMPO-oxidized nanocellulose (TEMPO-NC) from oil palm empty fruit bunch and 3-aminopropyltriethoxysilane (APS) in an ethanol/water medium at a low curing temperature of 40 °C as compared to those reported in the literature of above 100 °C. Confirmation of the grafting process can be seen from the new FTIR peaks at 810 cm -1 and 749 cm -1 which are attributed to the SiC stretching and SiC, and new 13 C NMR signals at 10.3, 21.7 and 42.7 ppm which are assigned to C7, C8, and C9 of the silylated TEMPO-NC. The decrease in the intensities of the cellulose peaks of C2, C3, C6 and C6' in the 13 C NMR indicates that silylation not only occurs on the hydroxyls, but more importantly on the TEMPO-NC carboxylic moiety of C6', which is postulated as being the primary factor for this successful modification. This is further corroborated by the emergence of three signals at 43, 61, and 69 ppm in the 29 Si NMR spectrum which corresponds to Si(OSi)(OR) 2 R', Si(OSi) 2 (OR)R', and Si(OSi) 3 R' units respectively. Additional evidence is provided by the EDX which shows an increase in Si weight percent of 1.94 after reaction. This silylated cellulose from OPEFB has the potentials to be used as bionanocomposite reinforcing elements., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Surface functionalization of cellulose nanocrystals (CNCs) is valuable option to tailor properties as well as increase opportunities for their application. In this study, the surface of CNCs was functionalized with 3-aminopropyltriethoxysilane (APTES), without using hazardous solvents and by a direct, simple and straightforward method. APTES was firstly hydrolyzed in water and then adsorbed onto CNC through hydrogen bonds, finally the chain hydrocarbon was covalently linked to the surface of CNC through SiOC bonds which formed via the condensation reaction between hydroxyl and silanol groups. The chemical modification of the CNCs surface was confirmed by ATR-IR and NMR spectroscopy. Experiments conducted by AFM and XRD showed no significant change in the CNC dimensions and crystalline structure as a result of the modification. The EDX and XPS results confirmed the exsistence of APTES onto the CNCs. Silylated CNC exhibited good thermal stability and a greater amount of residual char was formed at 500 °C compared to non-chemically modified CNC. Thus, The silylation of CNCs may offer applications in composite manufacturing, where these nanoparticles have limited dispersibility in hydrophobic polymer matrices, and as nano-adsorbers due to the presence of amino groups attached on the surface., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In this paper, we report the γ-ray sterilization effects in pH-sensitive polysilicon wire (PSW) sensors using a mixture of 3-aminopropyltriethoxysilane (γ-APTES) and polydimethylsiloxane (PDMS)-treated hydrophobic fumed silica nanoparticles (NPs) as a sensing membrane. pH analyses showed that the γ-ray irradiation-induced sensitivity degradation of the PSW pH sensor covered with γ-APTES/silica NPs nanocomposite (γ-APTES+NPs) could be restored to a condition even better than prior to γ-ray irradiation by 40-min of post-sterilization room-temperature UV annealing. We found that the trapping charges caused by γ-ray sterilization primarily concentrated in the native oxide layer for the pH sensor covered with γ-APTES, but accumulated in the γ-APTES+NPs layer for the γ-APTES+NPs-covered sensor. It is believed that mixing the PDMS-treated silica NPs into γ-APTES provides many γ-APTES/SiO(2) interfaces for the accumulation of trapping charges and for post-sterilization UV oxidation, thus restoring γ-ray-induced sensor degradation. The PDMS-treated silica NPs not only enhance the sensitivity of the pH-sensitive PSW sensors but are also able to withstand the two-step sterilization resulting from γ-ray and UV irradiations. This investigation suggests γ-ray irradiation could be used as a highly-efficient sterilization method for γ-APTES-based pH-sensitive biosensors.

The authors report a novel, effective and enhanced method of conjugating anticancer drug, paclitaxel and gallic acid with magnetosomes. Here, anticancer drugs were functionalised with magnetosomes membrane by direct and indirect (via crosslinkers: glutaraldehyde and 3‐aminopropyltriethoxysilane) adsorption methods. The prepared magnetosome–drug conjugates were characterised by Fourier transform infrared, zeta potential, field‐emission scanning electron microscope and thermogravimetric analysis/differential scanning calorimetry. The drug‐loading efficiency and capacity were found to be 87.874% for paclitaxel (MP) and 71.3% for gallic acid (MG), respectively as calculated by ultraviolet spectroscopy and high‐performance liquid chromatography. The drug release demonstrated by the diffusion method in phosphate buffer (PBS), showing a prolonged drug release for MP and MG, respectively. The cytotoxicity effect of the MP and MG displayed cytotoxicity of 69.71%, 55.194% against HeLa and MCF‐7 cell lines, respectively. The reactive oxygen species, acridine orange and ethidium bromide and 4, 6‐diamidino‐2‐phenylindole staining of the drug conjugates revealed the apoptotic effect of MP and MG. Further, the regulation of tumour suppressor protein, p53 was determined by western blotting which showed an upregulation of p53. Comparatively, the magnetosome–drug conjugates prepared by direct adsorption achieved the best effects on the drug‐loading efficiency and the increased percentage of cancer cell mortality and the upregulation of P53. The proposed research ascertains that magnetosomes could be used as effective nanocarriers in cancer therapy. [ABSTRACT FROM AUTHOR]

The development of active and stable catalyst is of significance for hydrogen generation from formic acid. Herein, a novel palladium catalyst with ultrafine metallic nanoparticles anchored on NH 2 -functionalized reduced graphene oxide (NH 2 -rGO) was synthesized by a facile wet chemical reduction process using sodium borohydride as the reducing agent. The TEM and XPS characterization results confirmed the successful functionalization of rGO with 3-aminopropyltriethoxysilane (APTES), which plays a very important role in evenly dispersing ultrafine Pd nanoparticles with a small average size of about 2.3 nm. As a result, the as-prepared Pd/NH 2 -rGO catalyst exhibited excellent activity with a high initial turnover frequency of 767 h−1 and 100% hydrogen selectivity, which was predominant among the currently available pure Pd catalysts towards formic acid dehydrogenation under room temperature. Image 1 • Pd nanoparticles are highly dispersed on NH 2 -functionalized rGO. • Pd/NH 2 -rGO exhibits high activity and 100% selectivity towards dehydrogenation of FA. • NH 2 -functionalization of rGO can improve the hydrophilicity of the catalyst. [ABSTRACT FROM AUTHOR]

• 3-aminopropyltriethoxysilane (APS) acts as both a binder and a polysulfide reactant. • Abundant amidogen in APS restrain the shuttle effect of polysulfides. • A stable 3D silica structure encapsulates nanoparticles to relieve the volume change. • A low-cost, environmentally-friendly, powerful network polymer cathode was obtained. One of the reasons why lithium-sulfur batteries have not yet been commercialized is a great attenuation of the capacity, although their theoretical capacity is ultrahigh. To alleviate this problem, we developed multifunctional organic matter, 3-aminopropyltriethoxysilane (APS), for preparing a uniform hybrid consists of silica 3D network skeleton and copolymerized sulfur nanoparticles (cpS). In this hybrid, abundant amidogen in APS induced polymerization with sulfur, which formed uniform copolymerized sulfur nanoparticles (nano sulfur), restraining the shuttle effect of polysulfides. Meanwhile, polycondensation APS not only acted as an efficiently binder, affording compact cathodes, but also formed a stable 3D silica structure to encapsulate sulfur nanoparticles, relieving the volume change of sulfur. Consequently, this binder-free cpS composite exhibited much enhanced electrochemical performances, including a high capacity of 1187.8 mAh·g−1 at 0.1 C and a low capacity fading of 0.0654% per cycle for 500 cycles at 1 C. This study paved the way for high-energy-density batteries by simply applying a low-cost, environmentally-friendly, powerful network polymer cathode material. [ABSTRACT FROM AUTHOR]

This study investigated the cellular uptake of fluorescein isothiocyanate‐labelled mesoporous silica nanoparticles (FITC‐MSNs), amine‐functionalised FITC‐MSNs (AP‐FITC‐MSNs) and their gallic acid (GA)‐loaded counterparts. Mesoporous silica nanoparticles were labelled with fluorescein isothiocyanate, functionalised by 3‐aminopropyltriethoxysilane (APTES) (AP‐FITC‐MSNs) and then loaded by GA. All nanoparticles were characterised by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, and X‐ray diffraction. The cytotoxicity of different concentrations of dyed nanoparticles was investigated using (3‐(4,5‐trihydroxybenzoic acid, dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay and flow cytometry. TEM images showed that the average particle sizes of FITC‐MSNs and AP‐FITC‐MSNs were about 100 and 110 nm, respectively. These nanoparticles were internalised by Caco‐2 cells, accumulated and dispersed into the cytoplasm, nucleus, and subcellular organelles. Nanoparticles containing GA clearly decreased the viability of cells. FITC‐MSNs showed no toxicity on Caco‐2 cells at concentrations of ≤50 µg/ml. Functionalisation of FITC‐MSNs using APTES decreased toxicity effects on the cells. It was found that FITC‐MSNs can be applied at low concentrations as a marker in the cells. In addition, AP‐FITC‐MSNs showed better biocompatibility with Caco‐2 cells than FITC‐MSNs, because of their positive surface charges. [ABSTRACT FROM AUTHOR]

Objective: Thialkalivibrio versutus D301 cells were immobilized on FeO nanoparticles (NPs) synthesized by an improved chemical coprecipitation method and modified with 3-aminopropyltriethoxysilane (APTES), then the immobilized cells were used in sulfur oxidation. Results: The prepared FeO-APTES NPs had a narrow size distribution (10 ± 2 nm) and were superparamagnetic, with a saturation magnetization of 60.69 emu/g. Immobilized cells had a saturation magnetization of 34.95 emu/g and retained superparamagnetism. The optimum conditions for cell immobilization were obtained at pH 9.5 and 1 M Na. The immobilization capacity of FeO-APTES NPs was 7.15 g DCW/g-NPs that was 2.3-fold higher than that of FeO NPs. The desulfurization efficiency of the immobilized cells was close to 100%, having the same sulfur oxidation capacity as free cells. Further, the immobilized cells could be reused at least eight times, retaining more than 85% of their desulfurization efficiency. Conclusion: Immobilization of cells with the modified magnetic NPs efficiently increased cell controllability, have no effect on their desulfurization activity and could be effectively used in large-scale industrial applications. [ABSTRACT FROM AUTHOR]

In this study, the property of 3-aminopropyltriethoxysilane modified graphite nanosheets (GNS) decorated with Fe3O4nanoparticles (Fe3O4-GNS-NH2hybrids) for adsorption of Hg(II) in aqueous solution were evaluated by batch methods. The adsorption mechanism was also studied by X-ray photoelectron spectroscopy. The effect of factors, such as pH, contact time, initial concentration of Hg(II) and the GNS content (wt.%) for Fe3O4in Fe3O4-GNS-NH2hybrid materials on Hg(II) removal were investigated. The equilibrium data were analyzed using the Langmuir and Freundlich isotherm models. The pseudo-first-order adsorption and the pseudo-second-order adsorption models were used to fit kinetics experimental data. The results showed that the main adsorption mechanism for Hg(II) was the formation of N-metal ions chemical complex, the solution pH value had a major impact on Hg(II) adsorption with optimal removal observed around pH 4.0–6.0, the Langmuir isotherm model was found to be suitable for the Hg(II) adsorption and the adsorption kinetic followed the pseudo-second-order equation for Fe3O4-GNS-NH2hybrid materials. [ABSTRACT FROM PUBLISHER]

Micron-scale hollow spheres were successfully constructed with silica nanoparticles by templating of polymer spheres. Subsequently, the use of 3-aminopropyltriethoxysilane (APTES) introduces carbon and oxygen defects in the silica nanoparticles resulting from calcination of the aminopropyl group. In this approach, the template of micron-scale polymer spheres was prepared from dispersion polymerization. Subsequent Stöber process results in the formation of a silica layer attached to the polymer sphere surfaces. After calcination, the obtained micron-scale hollow silica spheres were then studied on the relationship between the particle diameter and the surface morphology. The luminescence of hollow spheres was prepared through using APTES in Stöber process, and which of related the appearance of luminescence to the APTES concentration and calcination temperature. The results of this study can provide useful information for the structure of micron-scale hollow spheres and their application to luminescent materials. [ABSTRACT FROM AUTHOR]

In this work, 3-aminopropyltriethoxysilane modified FeO nanoparticles (ATPS-FeO) were used to modify glassy carbon electrode for aminopyrine determination. ATPS-FeO showed obviously catalytic activity and adsorptivity towards aminopyrine oxidation proven by the increased oxidation peak current and the decreased oxidation peak potential. The best analytical response was obtained by immobilizing 8 μL 3 mg/mL APTS-FeO dispersion with an accumulation time of 200 s at −0.2 V in 0.1 M phosphate buffer solution (pH 9.0). The oxidation peak current of aminopyrine showed linear relationship with its concentration in the range from 0.5 to 100 and 100 to 1600 μM. The detection limit was 0.1 μM (S/N = 3). The proposed method showed satisfactory repeatability and anti-interference ability. The fabricated electrode was successfully applied to determine aminopyrine in pharmaceutical formulations. [ABSTRACT FROM AUTHOR]

In this paper, we report the γ-ray sterilization effects in pH-sensitive polysilicon wire (PSW) sensors using a mixture of 3-aminopropyltriethoxysilane (γ-APTES) and polydimethylsiloxane (PDMS)-treated hydrophobic fumed silica nanoparticles (NPs) as a sensing membrane. pH analyses showed that the γ-ray irradiation-induced sensitivity degradation of the PSW pH sensor covered with γ-APTES/silica NPs nanocomposite (γ-APTES+NPs) could be restored to a condition even better than prior to γ-ray irradiation by 40-min of post-sterilization room-temperature UV annealing. We found that the trapping charges caused by γ-ray sterilization primarily concentrated in the native oxide layer for the pH sensor covered with γ-APTES, but accumulated in the γ-APTES+NPs layer for the γ-APTES+NPs-covered sensor. It is believed that mixing the PDMS-treated silica NPs into γ-APTES provides many γ-APTES/SiO2 interfaces for the accumulation of trapping charges and for post-sterilization UV oxidation, thus restoring γ-ray-induced sensor degradation. The PDMS-treated silica NPs not only enhance the sensitivity of the pH-sensitive PSW sensors but are also able to withstand the two-step sterilization resulting from γ-ray and UV irradiations. This investigation suggests γ-ray irradiation could be used as a highly-efficient sterilization method for γ-APTES-based pH-sensitive biosensors. [ABSTRACT FROM AUTHOR]

Abstract: This study investigated the interference elimination ability of a glucose sensor made of polysilicon wire (PSW) with a surface modified by 3-aminopropyltriethoxysilane mixed with polydimethylsiloxane-treated hydrophobic fumed silica nanoparticles plus ultra-violet illumination (γ-APTES+NPs+UV). Glucose sensing of the PSW sensor in the presence of five common interferences such as ascorbic acid (AA), uric acid (UA), acetaminophen (AP), l-cysteine (Lys), and citric acid (CA) was performed. We found that the disturbance caused by the interferences was low for interference-to-glucose concentration ratios up to 600:1 if the PSW surface is modified with γ-APTES+NPs+UV. The outstanding interference immunity of this PSW glucose sensor is believed to be mainly due to the fact that it is a dry-type sensor and the extremely low leakage of the γ-APTES+NPs membrane which allows the PSW to show three orders of magnitude lower leakage current than with the γ-APTES membrane only. In addition to its excellent interference immunity, the PSW glucose sensor with a line width of 100nm also exhibits a wide linear detection range, an ultra-high sensitivity, an ultra low detection limit, and it can be reused more than a thousand times without much sensitivity degradation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Highly dispersed catalysts were prepared by pre-modification with minimal 3-aminopropyltriethoxysilane and impregnation method. • Modified catalysts with lower Pd loading exhibited excellent hydrogenation performance compared with the commercial catalyst. • Modification of excessive 3-aminopropyltriethoxysilane will result in the decrease in metal dispersion for the intense anchoring sites. • The catalyst having the molar ratio of APTES /Pd = 2 with 0.2 wt% Pd showed the highest catalytic activity and selectivity. Faced with the problems of poor activity and inferior selectivity, highly dispersed Pd catalysts pre-modified by minimal 3-aminopropyltriethoxysilane (APTES) were prepared via impregnation reduction method. The amount of APTES was adjusted according to molar ratios of the APTES to Pd (APTES/Pd). The catalytic hydrogenation efficiency exhibited a volcano-shape trend with the amount of APTES. Grafting of suitable amount of APTES improved the dispersion of the Pd, increased the weak acid content of the γ-Al 2 O 3 and regulated the reducibility of the catalysts. The catalyst having APTES/Pd = 2 with 0.192 wt% Pd showed the highest catalytic activity and selectivity, with 100 % in the selectivity and the improvement of 27.3 % in the hydrogenation efficiency and 104.8 % in the H 2 O 2 productivity compared with the commercial catalyst (0.298 wt%). Furthermore, the APTES aggregated with the amount of APTES, which provided intense anchoring sites for the Pd and resulted in the increase in larger palladium nanoparticles. [ABSTRACT FROM AUTHOR]

Mesocellular foam (MCF)-like silica particles were produced from a nanometric mesoporous silica material with unique characteristics. Conditions during synthesis play a crucial role in the porous properties and chemical surface of MCF silica. In this work, the effects of various factors, including the H+/silica source molar ratio, the presence of a mineralizing agent, synthesis temperature, and the presence of combined surfactants (e.g., P123 and CTAB), on the porous properties of MCF silica were assessed. Additionally, the surface of these particles was modified with amine groups to evaluate performance as support for enzymatic immobilization. Thermomyces lanuginosus lipase was immobilized on the surfaces of nanoparticles functionalized with amine groups at pH 7 and 25 °C. Under these conditions, the enzyme had a net negative charge (pI = 4.4), while the functionalized particles had a net positive charge, which promotes enzymatic interactions. Image 1 • Mesocellular foam silica particles was made to obtain a nanometric silica. • Synthesis conditions effect were studied over the porous properties of MCF silica. • The particles modified with APTES were evaluate as support for enzymes. [ABSTRACT FROM AUTHOR]

In this paper, the antibacterial properties of TiO 2 photocatalysts modified by 3-aminopropyltriethoxysilane (APTES) are presented. It has been observed that the APTES modification enhancement of antibacterial efficiency (against Escherichia coli ATCC 29425) under artificial solar light (ASL). The results showed that all modified titania had higher disinfection efficiencies than starting TiO 2. For TiO 2 -4h-120 °C-300 a total sample elimination of the E. coli was achieved after 180 min of ASL irradiation. Improvement of antibacterial properties was attributed to the changes in the surface properties, i.e. zeta potential. Unlabelled Image • The TiO 2 -APTES photocatalysts were synthesized by a solvothermal process. • Modification with APTES improved antibacterial activity under artificial solar light. • Photoactivity depends on zeta potential and amount of OH radicals on TiO 2 surface. [ABSTRACT FROM AUTHOR]

• 3-Aminopropyltriethoxysilane (APTES) was chemical bonded to ZnO (zinc oxide). • ZnO/APTES exhibits desirable dispersibility and decreased surface defects. • The power conversion efficiency of ZnO/APTES based organic solar cells was 10.3%. When zinc oxide nanoparticles (ZnO NPs) are used as the electron transport layer (ETL) in organic solar cells (OSCs), the aggregation of ZnO NPs decreases the stability of the layer and produces many surface defects. Therefore, surface modification of the ZnO NPs is studied with to goal of improving the properties of the ETL. A material made of 3-aminopropyltriethoxysilane-connected ZnO NPs (ZnO/APTES) was used as ETL in inverted OSCs, and their properties were characterized by various methods. Experimental results showed that ZnO/APTES exhibited desirable dispersibility, decreased the surface defects, and improved the power conversion efficiency of the OSCs. [ABSTRACT FROM AUTHOR]