• Bulletin of the Korean Chemical Society
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• v.24 no.11
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• pp.1605-1608
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• 2003

To development an immunodetection method for DDT, 1,1,1-trichloro-2,2-bis(4-chorophenyl)ethane (p,p'-DDT) and its metabolites (p,p'-DDA, p,p'-DDE, p,p'-DDD), five derivatives of DDT haptens have been synthesised and characterized as coating ligands for antibody evaluation. The appropriate lengths of linkers were introduced to investigate a matching pair of coating ligand and antibody. Among these hapten derivatives, 2,2-bis(4-chlorophenyl)acetic acid (DDA), 5,5-bis(4-chlorophenyl)-5-hydroxypentanoic acid (DDHP) and 5,5-bis(4-chlorophenyl)-5-chloropentanoic acid (DDCP) were conjugated with keyhole limpet hemocyanin (KLH) for its use as an immunogen. The bovine serum albumin (BSA) conjugates of these derivatives were prepared as a coating ligand for monoclonal antibody screening. Fifteen monoclonal antibody clones were screened using these probes. 6,6-Bis(4-chlorophenyl)-6-hydroxyhexanoic acid (DDHH) and 3-[6,6-Bis(4-chlorophenyl)-6-hydroxyhexanoylamino]propanoic acid (DDHHAP), in addition to the above hapten derivatives, were conjugated to ovualbumin (OVA) and bovine serum albumin (BSA) for their use as coating ligands to measure the titration level of the antibody and the displacement of free analytes. The indirect competitive ELISA results indicate that the titration level and free analyte displacement were greatly influenced by the DDT derivatives and carrier proteins used. Three matching pairs of monoclonal antibodies and coating ligands were selected for the DDT immunoassay: antibody clone 1A3 and coating ligand DDA-OVA, 1A1 and DDHHAP-BSA, and 1A4 and DDHP-OVA.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.407.1-407.1
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• 2002

To develop immunostrip of DDT (4.4'-dichlorodiphenyl-2.2,2-trichloroethane) and its metabolites, DDT derivatives (DDA-. DDHP-. DDCP-. DDHH-. and DDHHAP-) were conjugated to carrier proteins (OVA and BSA) and three DDT derivatives (DDA. DDHP. DDCP) were conjugated to KLH for the use of coating ligand and immunogen. respectively. To screen the immunoreactivity of antibody to DDT derivatives, the coating ligand was evaluated by a competitive ELISA and DDHP-OVA was selected. (omitted)

• Bulletin of the Korean Chemical Society
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• v.23 no.10
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• pp.1413-1431
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• 2002

For the development of immunodetection method of 4,4'-dichlorodipheny-2,2,2-trichloroethane (p,p'-DDT), a persistent and broad toxic organochlorine insecticide, various DDT derivatives were synthesized and characterized for the use of immunogens and the coating ligands for the antibody evaluation. The appropriate lengths of linkers were introduced to investigate more efficient DDT derivatives. Among these hapten derivatives, 2,2-Bis(4-chlorophenyl)acetic acid (DDA), 5,5-Bis(4-chlorophenyl)-5-hydroxypentanoic acid (DDHP) and 5,5-Bis(4-chlorophenyl)-5-chloropentanoic acid (DDCP) were conjugated with keyhole limpet hemocyanin (KLH) for the use of immunogen to produce antibodies. 6,6-Bis(4-chlorophenyl)-6-hydroxyhexanoic acid (DDHH) and 3-[6,6-Bis(4-chlorophenyl)-6-hydroxyhexanoylamino]propanoic acid (DDHHAP) in addition to above hapten derivatives were conjugated to ovualbumin (OVA) and bovine serum albumin (BSA) for the use of coating ligands to measure the titration level of antibody and the displacement of free analytes. Three matching pairs of antibodies and coating ligands were selected for the simultaneous detection of p,p'-DDT and its related compounds of DDA and 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE) by investingating the displacement of free analytes in an indirect ELISA. These were PAb #1 and coating ligand DDCP-OVA, PAb #1 and DDHHAP-OVA, and PAb #3 and DDHHAP-OVA. The most useful immunoreaction for DDT analytes were obtained using PAb #3 and coating ligand DDHHAP-OVA showing 3.4 ng/mL of lower limit of detection. These results indicated that titration level and free analytes displacement were greatly influenced by hapten derivatized and carrier proteins conjugated.

• Bulletin of the Korean Chemical Society
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• v.22 no.9
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• pp.953-957
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• 2001

The specificity of conjugation site for coating ligands was investigated using toluene-bovine serum albumin (BSA) conjugates in which BSA was conjugated at the position of o-, m-, and ${\rho}-toluic$ acid. Toluene-BSA conjugated at ${\rho}-position$ showed a binding activity of about 89-95%, whereas, those conjugated at o- and m-position of toluene exhibited a binding activity of 5 and 11%, respectively. On the basis of the above result, coating ligands with various proteins (OVA, BSA, KLH) were compared by conjugating with $\rho-toluic$ acid, and toluene-KLH was considered as the best coating ligand for this ELISA. Indirect competitive ELISA method was developed using anti-toluene antibody and $\rho-position$ conjugated toluene-KLH. The dose-response curve constructed after kinetic and optimization studies showed a 1${\times}$10-4 - 1${\times}$102 mM detectable response range with 0.1 ${\mu}M$ detectability. In specificity test of the antibody, the binding capabilities of aromatic compounds substituted with nitro-, alkyl-, chloro-, and hydroxyl group were larger rather than those of aromatic compounds (benzene, toluene and xylene) themselves. Also, tests with soil and water samples that had been spiked with toluene resulted in 102.7-113.7% recovery.

• Archives of Pharmacal Research
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• v.20 no.1
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• pp.46-52
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• 1997

To obtain more sensitive immunoassay for methamphetamine (MA) determination, the optimum condition of enzyme-linked immunosorbent assay (ELISA) was investigated in regard to immunogens, antibody purification methods and coating tracers. Activated MA, N-(4-aminobutyl)methamphetamine (4-ABMA), was conjugated with bovine serum albumin (BSA) or keyhole limpet hemocyanin (KLH) and used as immunogen. The antibodies were purified by protein G chromatography or various immunoaffinity chromatography-linked MA-protein ligands, such as MA-BSA, MA-KLH or MA-ovalbumin (OVA). Each purified antibody was characterized by means of sensitivity and cross-reactivity using the three MA-protein coating tracers, MA-BSA, MA-KLH and MA-OVA. The best sensitivity of each antibody was acquired with the MA-OVA tracer although the tracer concentration and the antibody titer level at optimum condition were varied. The antibody with high titer level did not always yield good sensitivity. At optimum condition, immunoaffinity chromatography-purified antibodies were better for sensitivity and for specificity than protein G-purified antibodies. The cross-reactivity of the purified antibodies seemed to be affected by immunogen structure and showed somewhat different patterns according to the immunoaffinity ligand utilized. These data show that the antibody purification method as well as choice of coating tracer and immunogen is essential for the sensitivity and specificity of EIA; the optimum condition for assay should be discovered using various methods and combinations.

• Progress in Superconductivity
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• v.9 no.1
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• pp.85-90
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• 2007

Lanthanum aluminate($LaAlO_3$) film has been prepared on single crystal and metal substrates by dip coating method. Lanthanum acetate and aluminum were prepared via ligand exchange starting from lanthanum nitrate hexahydrate and aluminum nitrate hexahydrate in acetate glacial acetic acid solution after being refluxed. Coating solution was obtained by diluting the gel with methanol and 2-methoxyethanol to adjust the total cation concentration to 0.67 M. Precursor coated film was prepared by dip-coating with a speed of 25 mm/min on various substrates such as $LaAlO_3$ (001), MgO(001), $SrTiO_3$(001) single crystal, LMO/MgO/Ni-alloy. Thin films have been obtained by heat treating the precursor film at various temperatures from $600^{\circ}C{\sim}900^{\circ}C$ and various heating rate from $0.83^{\circ}C/min{\sim}1.25^{\circ}C/min$ under $Ar/O_2$ mixture containing 1000ppm oxygen. The films have been characterized by scanning electronic microscopy (SEM) and X-ray diffraction (XRD). XRD analysis for the prepared film showed that $LaAlO_3$ thin films with a preferred orientation of (100) plane parallel to substrate surface were obtained at $800^{\circ}C(1.11\;^{\circ}C/min)$ on LMO/MgO/Ni-alloy substrate, but the intensity decreased with the increase of heat treatment temperature.

• Journal of Environmental Science International
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• v.8 no.2
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• pp.205-209
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• 1999

Iron hydroxides are good adsorbents for uncomplexed metals, some metal-ligand complexes and many metal oxyanions. However, their adsorption properties of these precipitations are not fully exploited in wastewater treatment operations because of difficulties associated with their separation from the aqueous phase. This study describes experiments in which iron hydroxides were coated onto the surface of ordinary adsorbents(Sea sand) that are very resistant to acids, The coated adsorbents were used in adsorption of oxyanionic metals. The process was successful in removing some anions such as $SeO_3(-II)$ over a wide range of metal concentrations and sorption of oxyanionic metals increased with decreasing pH. Formation of two surface complexes for oxyanionic metals adsorption on iron hydroxides comprise (1) complexation of the free anion by a positively charged surface site, and (2) protonation of the adsorbed anion (or alternatively adsorption of a protonated form from solution) The coated adsorbents are inexpensive to prepare and could serve as the basis of a useful oxyanionic metal removal.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.365.2-365.2
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• 2014

Nickel sulfide (NiS) has been utilized in optoelectronic applications, such as transformation-toughening agent for materials used in semiconductor applications, catalysts, and cathodic materials in rechargeable lithium batteries. Recently, high quality nickel sulfide thin films have been explored using ALD/CVD technique. Suitable precursors are needed to deposit thin films of inorganic materials. However, nickel sulfide precursors available for ALD/CVD process are very limited to nickel complexes with dithiocarbamate and alkanethiolate ligands. Therefore, it is essential to prepare novel nickel sulfide suitable for ALD/CVD precesses. Herein we report on the synthesis and characterization of new nickel sulfide complex with designed aminothiolate ligand. Furthermore thin films of NiS have been prepared on silicon oxide substrates by spin coating nickel precursor 10 wt% in THF. The novel complex has been characterized by means of 1H-NMR, elemental analysis, thermogravimetric analysis (TGA), X-ray Diffraction (XRD) and scanning electron microscope (SEM).

• BMB Reports
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• v.30 no.5
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• pp.303-307
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• 1997

Grb2, which is composed of a Src homology 2 (SH2) domain and two Src homology 3 (SH3) domains, is known to serve as an adaptor protein in signaling for Ras activation. Thus, a blocker of the Grb2 interactions with other proteins can be a potential candidate for an anticancer drug. In this study, we have developed a high throughput screening method for SH3 domain binding ligands and blockers. Firstly, we made and purified the glutathione S-transferase (GST)-fusion proteins with the Grb2 SH2 and SH3 domains, and the entire Grb2. This method measures the binding of a biotin-labeled oligopeptide, derived from a Grb2/SH3 binding motif in the hSos, to the GST-fusion proteins, which are precoated as glutathione S-transferase fusion protein on a solid phase. When $1\;{\mu}g$ of each fusion protein was used to coat the wells, both N- and C- terminal SH3 the domains as well as the whole of Grb2 were able to interact with the biotin-conjugated ligand peptide, while the SH2 domain and GST alone showed no binding affinity. Although N- and C- terminal SH3 domains showed an increase of binding to the ligand peptide in proportion to the amount of peptide, the GST fusion protein with Grb2 demonstrated much higher binding affinity. GST-Grb2 coating on the solid phase showed a saturation curve; 66 and 84% of the maximal binding was observed at 100 and 300 ng/$100\;{\mu}l$, respectively. This binding assay system was peptide sequence-specific, showing a dose-dependent inhibition with the unlabeled peptide of SH3 binding motif. Several other peptides, such as SH2 domain binding motifs and PTB domain binding motif, were ineffective to inhibit the binding to the biotin-conjugated ligand peptide. These results suggest that our method may be useful to screen for new anticancer drug candidates which can block the signaling pathways mediated by SH3 domain binding.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.347.2-347.2
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• 2016

Recently, in order to improve the performance of the colloidal quantum dot solar cells (CQDSCs), various efforts such as the modification of the cell architecture and surface treatment for quantum dot (QD) passivation have been made. Especially, the incorporation of halides into the QD matrix was reported to improve the performances significantly via passivating QD trap states that lower the life-time of the minority-carrier. In this work, we fabricated a lead sulfide (PbS) QD bilayer treated with different ligands and utilized it as a photoactive layer of the CQDSCs. The bottom and top PbS layer was treated using metal iodide ($MI_x$ and butanedithiol (BuDT), respectively. All the depositions and ligand treatments were carried out in air using layer-by-layer spin-coating process. The fabrication of the active layers as well as the n-type zinc oxide (ZnO) layer was successfully carried out on the bendable indium-tin-oxide (ITO)-coated polyethylene terephthalate (PET) substrate, which implies that this technique can be applied to the fabrication of flexible and/or wearable solar cells. The power conversion efficiency (PCE) of the CQDSCs with the architecture of $PET/ITO/ZnO/PbS-MI_x/PbS-BuDT/MoO_x/Ag$ reached 4.2 %, which is significantly larger than that of the cells with single QD (PbS-BuDT) layer.