Elemental and isotopic ratio analyses, together with size distribution analyses, have been made from single Pt- and Pt-Au nanoparticles using a multiple collector ICP-mass spectrometer equipped with a high-time resolution data integration system. With the present system set-up, high-speed data integration (up to 100000 Hz) with nearly 100 % time-integration efficiencies can be achieved from up to 4 high-gain ion collectors, enabling us to measure elemental and isotopic ratio analyses from single nanoparticles. The measured ¹⁹⁵Pt/¹⁹⁴Pt ratio from Pt NPs of two sizes (30 nm and 50 nm) showed that the repeatability of the isotope ratio measurements was mainly controlled by the counting statistics of the signal, suggesting that effective data acquisition could be achieved under transient signals produced from the NPs. The analytical capability of the system was evaluated by monitoring the Au/Pt ratio from multi-component NPs produced through the laser ablation in liquid (LAL) technique. The MC ICP-MS analysis for the Pt-Au NPs revealed that both the size and Au/Pt ratio of the NPs varied significantly by reflecting the laser ablation conditions. Possible mechanisms for the variations in the sizes and Au/Pt ratios of the Pt-Au NPs produced by the LAL technique will be discussed in this study.

Precise molecular recognition is required for various research and industrial fields, like sensing materials and pharmaceuticals. Oriented template immobilization-based molecular imprinting has been developed for creating artificial molecular recognition materials with high affinity and selectivity towards various target molecules, including small molecules, proteins, and glycoproteins. Molecularly imprinted polymers (MIPs) are artificial polymer-based molecular recognition materials. The molecular imprinting process involves a template polymerization approach, where the molecular complex of functional monomers and the template molecule is copolymerized by using crosslinking agents and a comonomer, followed by removal of the template molecules from the polymer matrix, yielding molecular recognition nanocavities bearing multiple interaction sites. The oriented immobilization of template molecules and precision polymer synthesis with strictly controlled polymer thickness produces precise molecular recognition cavities in MIPs. To date, the proposed oriented template immobilization-based molecular imprinting process has been successfully applied to polymeric thin-layer-based materials, affording highly sensitive and selective sensing materials. This approach can be applied to materials of various shapes, including particle-based materials, which leads to high-affinity chromatography agents and nanoparticle-based pharmaceutical materials. Therefore, the novel strategy based on molecular imprinting described herein can be applied to create various intelligent materials.

In the present work, pH response glasses with excellent chemical durability and small resistance were fabricated, the when lithium concentration in a glass membrane increased, and rare earth metal (Sc, Y and La) oxides were added in the glass. We tried to construct a pH electrode with fabricated pH response glasses, and to evaluate it for the sensitivity, linearity, alkali error and response of tap water. Next, we prepared pH electrode capable of measuring a micro volume (50 μL) by using the optimum pH response glasses. The performance results of the developed pH electrode for a micro volume that satisfied the standard JIS. The developed pH electrode may become commercially available.

DNA and RNA are among the most fundamental molecules of all life forms. DNA and RNA quantification are essential in various fields, such as biomedicine, environment, and food. This paper describes the development and the application of simple, accurate, and cost-effective methods for the quantification of specific nucleic acid sequences. These methods are called universal quenching probe; Universal QProbe (alternately binding probe competitive polymerase reaction); ABC-PCR (alternately binding probe loop-mediated isothermal amplification); ABC-LAMP. Moreover, this paper describes the development and application of a high-throughput screening assay of DNA/RNA helicase inhibitors (e.g. hepatitis C virus NS3 helicase). The key feature of these methods is a phenomenon in which the fluorescence of a dye is quenched by electron transfer to a guanine base at a particular position. Furthermore, mammalian genomes produce huge numbers of noncoding RNAs. However, the functions of most noncoding RNAs are unclear, and novel techniques that can distinguish functional noncoding RNAs are required. Studies of mRNAs have revealed that the half-life of each mRNA is closely related to its physiological function, raising the possibility that the RNA stability of a noncoding RNAs reflects its function. This paper describes the development of and the application of a genome-wide method, which we named 5’-bromo-uridine immunoprecipitation chase–deep sequencing analysis (BRIC-seq). These methods will provide an understanding complex biological phenomena.

The first screening for commercial polyol esters was carried out by a newly developed prototype of direct inlet probe (DIP) - ion attachment ionization/TOFMS (IA/TOFMS). DIP is a heating probe for a sampling cell, which works at ca. 30 Pa. It can be evolved semi-volatile and less-volatile compounds by suppressing thermal decomposition. The system configuration should be advantageous for the performance of real-time measurements for each cationized molecule [M+Li]⁺. In this system, 5 kinds of polyol esters were characterized by POE molecules, free fatty acids and other mixtures. One measurement is completed in about 10 to 15 minutes, and polyol esters with long chain fatty acids can be clearly detected.

A non-enzymatic fluorescence method for the determination of hydrogen peroxide (H₂O₂) in river water samples was optimized to improve the reaction time and interference by coexisting nitrite. The method was based on the hydroxylation reaction of terephthalate (TP) by a hydroxyl radical formed from a reaction between H₂O₂ and Fe(II), resulting in the formation of a strongly fluorescent 2-hydroxyterephthalate (HTP). The concentration of Fe(II) strongly affected the reaction time and the signal intensity; the reaction time was shortened by increasing of Fe(II), while the signal intensities decreased with increase Fe(II). The addition of sodium sulfate in the reaction mixture reduced the interference of coexisting nitrite. Under the optimized conditions, a 3-5 nmol L⁻¹ detection limit and a 0.85 % precision at 300 nmol L⁻¹ H₂O₂ were obtained. The diurnal change of hydrogen peroxide was investigated at the Kurose River in Higashi-Hiroshima City, Hiroshima Prefecture. The concentrations of H₂O₂ were increased in the daytime. The maximum concentration of H₂O₂ was observed at 14 : 00, while the minimum was observed before sunrise.

The homogeneity and stability of reference materials for the determination of Cd in white and brown rice grains were evaluated using atomic absorption spectrometry (AAS) after HNO₃-H₂SO₄ digestion. Two kinds of rice grain reference materials were prepared by adding 100 g each of white and brown rice grains (both from Niigata prefecture, Japan) to 750 mL of methanol containing 40 μL of 1000 mg L⁻¹ Cd standard solution (40 μg as Cd), and then heating them at 300°C for 1 h on a hot plate to evaporate the solvent. Each rice grain reference material (100 g) was packed in 10 glass bottles (10 g each). The homogeneity of Cd in the rice grain reference materials was estimated by an analysis of the variance after the Cochran test. A total of 9 samples (3 samples each from 3 bottles) were subjected to the homogeneity test. There was no significant difference between the within-bottle and between-bottle variances, indicating that both rice grain reference materials were sufficiently homogeneous. The stability of Cd in the rice grain reference materials was estimated by regression analysis. For a stability study, 6 bottles were stored in the dark at room temperature for a period of 6 months. The rice grain reference materials were stable for 5 months for white rice grain and for 6 months for brown rice grain. Elemental mapping images of the Cd of a longitudinal section of a white rice grain and a brown rice grain, using a micro-X-ray fluorescence instrument, suggested that the added Cd is present in the outer layers of the rice grain reference materials. The rice grain reference materials with a Cd concentration of approximately 0.31 mg kg⁻¹, prepared in this study, can be used for validating the AAS determination of Cd in white and brown rice grains.