• Carbon letters
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• v.10 no.4
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• pp.325-328
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• 2009

This cycloaddition of [70]fullerene with methyl azidoacetate in benzene under ultrasonic irradiated condition afforded the closed [5,6]-bridged aziridino[70]fullerene derivative, which was unusual product of cycloaddition to the 5,6-junction of fullerene. Its structure was determined by FAB-MS, UV-vis, $^1H-$ and $^{13}C$-NMR spectral data. The closed [5,6]-bridged aziridino[70]fullerene-functionalized gold nanoparticle films were self-assembled using the layer-by-layer method on the reactive of glass slides functionalized with 3-mercaptopropyl trimethoxysilane. The functionalized glass slides were alternately soaked in the solution containing closed the [5,6]-bridged aziridino[70]fullerene and 4-aminothiophenoxide/hexanethiolate-protected gold nanoparticles. The closed [5,6]-bridged aziridino[70]fullerene-functionalized gold nanoparticle films have grown up to 5 layers depending on the immersion time. The self-assembled nanoparticle multilayer films were characterized using UV-vis spectroscopy showed that the surface plasmon band of gold at 527 nm gradually became more evident as successive layers were added to the films.

• Journal of Sensor Science and Technology
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• v.21 no.3
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• pp.186-191
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• 2012

In this paper, we present a pH measurement method that uses a microcantilever-array-based biosensor system. It is composed of microcantilever array, liquid cell, micro syringe pump, laser diode array, position sensitive detector, data acquisition device, and data processing software. Four microcantilevers are functionalized with pH-sensitive MHA(mercaptohexadecanoic acid) as a probe, while three microcantilevers are functionalized with HDT(hexadecane thiol) as reference. We prepare PBS(phosphate buffered saline) solutions of different pH and inject them into the liquid cell with a predefined volumetric speed at regular time intervals. The functionalized mircocantilevers in the liquid cell deflect as a self-assembled monolayer on the microcantilever binds with probe molecules in the solution. The difference in deflection between the MHA-covered probe microcantilever and the HDT-covered reference microcantilever was used to compensate for thermal drift. The deflection difference clearly increases with increasing pH in the solution. It was shown that when the pH values of the PBS solutions are high, there were large variations in the deflection of microcantilevers, whereas there were small variations for low pH value. The experimental results show that the microcantilever array functionalized with MHA and HDT can detect pH value with good repeatability.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.2
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• pp.171-177
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• 2005

Coconut based activated carbon and silica-gels were impregnated with 3-aminopropyltri ethoxysilan(APS) and N-(2-aminoethyl)-3-aminopropyl triethoxysilane (AEAPS) in order to investigate the effect of the amine group and the pore size of the supports on the removal of hydrogen cyanide(HCN) and aldehydes in mainstream smoke(MS). The physicochemical properties of the supports were analyzed by using thermal gravity analyzer(TGA), $N_2$ adsorption and desorption isotherms$(BET,\;N_2)$, and SEM-EDS. According to our experimental data, there was no significant difference in the delivery amount of HCN and aldehydes of non-functionalized silica-gels having meso-pores bigger than $20\AA$. In the case of silica-gels functionalized with APS(APS silica-gel), the delivery amounts of hydrogen cyanide(HCN) and aldehydes decreased with the increase of APS concentration. Silica-gel functionalized with AEAPS(AEAPS silica-gel) showed higher removal efficiency than that of APS silica-gels. The delivery amounts of HCN and aldehydes of activated carbon impregnated with APS and AEAPS increased with the increase of the APS and AEAPS concentrations. In accordance with the specific surface area analysis results, APS and AEAPS molecules decreased the specific surface area by blocking the micro-pores of the activated carbon. The volatile organic components removal efficiency by the micro-pores was higher than that of the amine group impregnated into the activated carbon.

• Journal of the Korean institute of surface engineering
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• v.48 no.6
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• pp.303-308
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• 2015

Pd-functionalized ${\beta}-Bi_2O_3$ nanowires are synthesized by thermal evaporation of Bi powder using VLS mechanism followed by Pd coating and annealing. In this study, sensing properties of Pd-functionalized ${\beta}-Bi_2O_3$ nanowires sensor to selected concentrations of $NO_2$ gas were examined. Scanning electron microscopy showed that the nanowires with diameters in a range of 100 - 200 nm and lengths of up to a few tens of micrometers. Transmission electron microscopy and X-ray diffraction confirmed that the products corresponded to the nanowires of ${\beta}-Bi_2O_3$ crystals and Pd nanoparticles. Pd-functionalized ${\beta}-Bi_2O_3$ nanowires sensor showed an enhanced sensing performance to $NO_2$ gas compared to as-synthesized ${\beta}-Bi_2O_3$ nanowires sensor. As synthesized and Pd-functionalized ${\beta}-Bi_2O_3$ nanowire sensors showed responses of 178% - 338% and 196% - 535% at $300^{\circ}C$, respectively, to 0.05 - 2 ppm $NO_2$. In addition, the underlying mechanism of the enhancement of the sensing properties of ${\beta}-Bi_2O_3$ nanowires by Pd-functionalization is discussed.

• Applied Chemistry for Engineering
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• v.29 no.1
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• pp.97-102
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• 2018

In this work, the surface of gold nanoparticles (AuNPs) was modified with small molecules including mercaptoundecanoic acid (MUA) and L-lysine for the development of highly sensitive lateral flow (LF) sensors. Uniformly sized AuNps were synthesized by a modified Turkevich-Frens method, showing an average size of $16.7{\pm}2.1nm$. Functionalized AuNPs were then characterized by transmission electron microscopy, UV-vis spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The stable conjugation of AuNPs and antibodies was obtained at pH 7.07 and the antibody concentration of $10{\mu}g/mL$. The functionalized AuNP-based LF sensor exhibited lower detection limit of 10 ng/mL for hepatitis B surface antigens than that of using the bare AuNP-based LF sensor (100 ng/mL).

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.47-50
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• 1997

We synthesized N-Hydroxysuccinimidyl (NHS) azidobenzoate as a cross-linking reagent for immobilization of peptide onto the solid surface. Thin polystyrene(PS) films spin-coated with a NHS azidobenzoate solution were exposed with ultraviolet light at 245nm$(3.3mW/cm^2)$ for 5 min. The NHS active ester groups became covalently attached to the polymer via photogenerated, highly reactive nitrene intermediates derived from NHS azidobenzoate. Using this technique, it is demonstrated that well-defined surface regions can be functionalized with a minimum observable feature size of 1mm for UV exposure. Through reaction of this functionalized PS surface with primary amine-containing biomolecules, biological molecule had been immobilized on the polymer surface.

• KIEE International Transactions on Electrophysics and Applications
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• v.11C no.4
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• pp.146-149
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• 2001

The functionalized dendrimer containing 48 azobenzene was synthesized. Many isolated featureless domains were explicitly observed even at the air/water interface. Also, these monolayers were representatively observed, showing the change of surface pressure with irradiation time and wavelength. In AFM images, larger domains irregularly shaped structures on the top, while smaller ones were free from such defects. In the optical absorption spectra of the monolayer films by UV irradiation and heat treatment, only the photoiosmerization of the G4-48 Azo monolayers was observed, revealing a decrease of absorbance peaks without any change of the spectral shape. This suggests that the functional group and the symmetric chain affect optical behavior and morphological change.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1133-1137
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• 2011

Ordered array of gold nanoparticles (Au NPs) over ITO glass was investigated in terms of ITO pretreatment, particle size, and diamines with different chain length. Owing to the indium-tin-oxide (ITO) layer coated on the glass, the substrate surface has a limited number of hydroxyl groups which can produce functionalized amine groups for Au binding, which resulted in the loosely-packed array of Au NPs on the ITO surface. Diamine ligand as a molecular linker was introduced to enhance the lateral binding of adjacent Au NPs immobilized on the amine-functionalized ITO glass, consequently leading to the densely-packed array of Au NPs over the ITO substrate. The molecular bridging effect was strengthened with the increase of chain length of diamines: C-12 > C-8. The packing density of small Au NPs (< 40 nm) was significantly increased with the increase of C-8 diamine, but large Au NPs (> 60 nm) did not produce densely-packed array on the ITO glass even for the dosage of C-12 diamine.

• Macromolecular Research
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• v.17 no.4
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• pp.232-239
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• 2009

This paper describes the simple nanopatterning of proteins on polyelectrolyte surfaces using microcontact printing with a nanopatternable, hydrophilic composite nanomold. The composite nanomold was easily fabricated by blending two UV-curable materials composed of Norland Optical Adhesives(NOA) 63 and poly(ethylene glycol) dimethacrylate(PEG-DMA). NOA 63 provided stable nanostructure formation and PEG-DMA induced high wettability of proteins in the nanomold. Using the composite mold and functionalized surface with polyelectrolytes, the fluorescent, isothiocyanate-tagged, bovine serum albumin(FITC-BSA) was successfully patterned with 8 nm height and 500 nm width. To confirm the feasibility of the protein assay on a nanoscale, a glycoprotein-lectin assay was successfully demonstrated as a model system. As expected, the lectins correctly recognized the nano-patterned glycoproteins such as chicken ovalbumin. The simple preparation of composite nanomold and functionalized surface with a universal platform can be applied to various biomolecules such as DNA, proteins, carbohydrates, and other biomolecules on a nanoscale.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.5
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• pp.719-724
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• 2011

The excessive phosphate in water causes eutrophication which destroys water environment. In this study, mesoporous silica was synthesized and several functional groups were attached on it. Samples were tested to identify the ability to remove phosphate. The structures of synthesized materials were analyzed by X-ray diffractions (XRD), Fourier transform-infrared (FT-IR) and surface area analysis, Brunauer-Emmett-Teller (BET). To determine the maximum phosphate adsorption capacities and sorption rate, the equilibrium test and kinetic test was conducted. Among functionalized SBA-15 samples, pure SBA-15 didn't adsorb phosphate but Al-SBA-15 and Ti-SBA-15 showed good performances to remove phosphate. The maximum phosphate adsorption capacity of Al-SBA-15 was efficient compared to other adsorbents.