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Volume 67, Issue 2
Displaying 1-5 of 5 articles from this issue
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Annual Topic “membrane” : Accounts
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Kazuharu SUGAWARAArticle type: Annual Topic “membrane” : Accounts
2018 Volume 67 Issue 2 Pages 73-79
Published: February 05, 2018
Released on J-STAGE: March 03, 2018
JOURNAL FREE ACCESSIn the present study, electrodes covered with biopolymer film were constructed as a scaffold for the sensing of biological molecules. First, chitin powder was dissolved with lithium chloride and organic solvents, and chitin film was prepared. The protonated film could immobilize glucose oxidase due to an electrostatic interaction. When a platinum electrode was covered with the film, a glucose sensing system was easily fabricated. Next, biological molecules were detected by using an electrode covered with protein/chitin film. To electrochemically measure a biological molecule, the molecule was labeled with an electroactive compound. The measurement principle was that the electrode response changed due to a competitive reaction to the binding sites of the protein between the target molecule and the labeled molecule. In addition, a carbohydrate molecular recognition protein was modified on the chitin film because the protein combined with the chitin surface through N-acetylglucosamine moieties. As a result, a chitin film with a new function was fabricated. To examine whether the film was suitable for a scaffold, a carbohydrate probe with an electroactive compound was synthesized through Schiff base reaction. When the amount of the probe was constant, the peak current increased as the amount of the native carbohydrate increased. Therefore, immobilization of the protein on the film was simply achieved based on molecular recognition. On the other hand, the electrochemical detection of protein was carried out using an electrode coated with collagen including a metal complex. The proteins in foods were determined using the electrode with the complexes. Furthermore, carbon/biopolymer film with conductivity was fabricated to improve the sensitivity of the target biomolecule. The sensitivities of several biomolecules were three-fold compared with that using the electrode with collagen alone. Consequently, these systems with a high biocompatibility can be applied to the sensing of biological molecule.View full abstractDownload PDF (1082K)
Annual Topic “photo” : Accounts
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Tadaaki NAGAO, Kai CHEN, Thang Duy DAO, Satoshi ISHII, Robert P.H. CHA ...Article type: Annual Topic “photo” : Accounts
2018 Volume 67 Issue 2 Pages 81-94
Published: February 05, 2018
Released on J-STAGE: March 03, 2018
JOURNAL FREE ACCESSSurface-Enhanced Infrared Absorption (SEIRA) is a phenomena in which vibrational signals from trace amounts of analyte or sub-monolayer molecules adsorbed on solid surfaces are dramatically enhanced in their intensities. By utilizing the localized surface plasmon resonances of infrared optical antennas and metamaterials, strong signal enhancements of molecules become operative in an effective manner to realize high sensitivity vibrational sensing. Recent developments in nanostructure fabrication techniques as well as their surface functionalization techniques have enabled us to propose and fabricate various types of advanced SEIRA nanodevices in nanophotonics and in nano-biosensing fields as well as in analytical chemistry. Moreover, recent advances in searching appropriate infrared plasmonic materials beyond noble metals have widened the possibilities to utilize low-cost base metal and conductive metal oxides for SEIRA applications. In this review article, we introduce the detection of dilute molecules and pathogenic enzymes in solution by an in situ ATR-IR method, as well as protein SEIRA sensing by surface-functionalized Al optical antennas and metamaterials. We also introduce our new approach to utilize infrared surface plasmons in optical antenna array made of phosphonic acid-functionalized conductive oxide nanorods to detect proteins with high specificity and sensitivity.View full abstractDownload PDF (4175K)
Research Papers
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Shoji IMAI, Yuhei YAMAMOTO, Kaito SHIMIZU, Eri KANEKIYO, Jun NISHIMOTO ...Article type: Research Papers
2018 Volume 67 Issue 2 Pages 95-101
Published: February 05, 2018
Released on J-STAGE: March 03, 2018
JOURNAL FREE ACCESSFresh snow and rain samples were collected at remote areas that were 15 km far from a provincial industrial city, in order to suppress any influences of coarse particulates. The concentrations of lead and cadmium in fresh snow collected in remote areas along Japan Sea in Honshu Island, Japan in 2014 and 2015 were reported along with these concentrations in fresh snow and rain occuring in remote areas in Shikoku Island, Japan at 2010, 2014 and 2015. The origins of air mass providing snow and rain were estimated by using a 24 h back-trajectory. The correlation between Pb and Cd was obtained to be [Pb]/[Cd] = 27.4±2.8 (R2 = 0.979) in fresh snow derived from a cold air mass from North Eastern China (Heilongjiang) – Far Eastern Russia (Maritime Province) and [Pb]/[Cd] = 2.8±0.4 (R2 = 0.732) in rain and fresh snow derived from Japan. The origin of air mass for Pb and Cd included was assigned to AREA’s (A, Hebei; B, Liaoning-Jilin; B2, Korea Peninsula; C, Heilongjiang- Maritime Province; D, Japan) corresponding to the regression line at a short distance from the plotted point observed in fresh snow samples in remote areas of Honshu Island on a Pb-Cd diagram. There were some samples that indicated a different AREA assigned by between hexagonal raidar plot of the chemical composition of inorganic small spherical particles and this Pb-Cd plot diagram method. The difference in the air mass origin assigned by different tracers used could be caused by differences in the long-range transport mechanism between the inorganic spherical small particles (φ 1–3 μm) and aerosol of Pb and Cd as sulfate. The reason can also be explained by varying back-trajectory line during the snow falling event.View full abstractDownload PDF (1198K)
Notes
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Susumu KAWAKUBO, Yusuke KOMATSU, Teruyoshi KOMIYA, Ikuo UETA, Yasutada ...Article type: Notes
2018 Volume 67 Issue 2 Pages 103-108
Published: February 05, 2018
Released on J-STAGE: March 03, 2018
JOURNAL FREE ACCESSA catalytic determination method for mercury has been developed by combining two catalytic reactions: mercury-catalyzed dissociation of iron from Fe(CN)64− and iron-catalyzed oxidative coupling of 3-metyl-2-benzothiazoline hydrazone with N,N-dimetylaniline in the presence of H2O2. Under an optimized reaction condition, the first reaction was carried out for a reaction time of 10 min at a reaction temperature of 60°C and the second reaction was done for 5 min at 25°C. The absorbance of an indamine dye produced by the second reaction was measured at 590 nm. The absorbance was proportional to the concentration of mercury. The concentration of toxic CN− generated from the first reaction was reduced to that much less than the effluent standard in Japan. Mercury was separated from interfering foreign ions by the reducing evaporation at 40°C for 10 min using a Conway microdiffusion unit. Mercury ions in sample were reduced by tin(II), and mercury vapor generated was absorbed into an acidic permanganate solution. The interference of chloride ion, evaporating with mercury, was inhibited by adding thiourea into the sample. In the analysis of a 1-mL sample, the calibration curve of mercury was linear up to 200 ng mL−1, and the detection limit of mercury was 5 ng mL−1. The proposed method was applied to river water and industrial waste samples. The recoveries of mercury (50 or 150 ng) added were satisfactory within an error of 5 %.View full abstractDownload PDF (768K)
Analytical Reports
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Mikio KUZUYAArticle type: Analytical Reports
2018 Volume 67 Issue 2 Pages 109-116
Published: February 05, 2018
Released on J-STAGE: March 03, 2018
JOURNAL FREE ACCESSThe applicability of laser-induced plasma spectroscopy (LIPS) for sorting of aluminum alloy scrap was studied. The combination of a pulsed Nd:YAG laser with an objective lens having a long focal length of 600 mm was used to generate plasmas, and the emitted light was analyzed spectroscopically by a compact fiber-optic spectrometer having a CCD array detector. The emission characteristics of laser-induced plasmas, in terms of the laser pulse energy and sample height, were investigated to determine the optimum conditions for quantitative analysis. The experimental results showed that the line-to-background ratio was maximized at a laser pulse energy of around 30 mJ. Also, the variations in the spectral line intensity due to changes in the sample height could be compensated by the method of an internal standard, which normalizes the line intensity of the analyte element to the line intensity of the matrix element. Based on the results, standard aluminum alloy samples were analyzed and calibration curves were constructed for elements of silicon, copper, zinc, magnesium and manganese. Aluminum alloy scrap pieces, consisting of cast and wrought alloys, were sorted successfully by the obtained calibration curves.View full abstractDownload PDF (1496K)
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