Masaya Kakuta

In this work, an inkjet-printed single-step and homogeneous bioassay microdevice was developed with a poly(dimethylsiloxane) (PDMS) microchannel for easy fabrication and mass production. An inkjet printer can dispense reactive reagents as nanoliter droplets on a PDMS microchannel accurately. Therefore, homogeneous and reproducible dispensing of rea...

In this study, we report an inkjet printing-based method for the immobilization of different reactive analytical reagents on a single microchannel for a single-step and homogeneous solution-based competitive immunoassay. The immunoassay microdevice is composed of a poly(dimethylsiloxane) microchannel that is patterned using inkjet printing by two t...

In this study, we report an inkjet printing-based method for the immobilization of different reactive analytical reagents on a single microchannel for a single-step and homogeneous solution-based competitive immunoassay. The immunoassay microdevice is composed of a poly(dimethylsiloxane) microchannel that is patterned using inkjet printing by two t...

The methylene blue (MB) adsorption states on the titania nanoparticles (NPs) prepared by two surfactant removal processes were investigated to demonstrate the singlet oxygen generation efficiency. The NPs with the BET surface areas of 250–350 m ² /g exhibited the spherical particle sizes of 100–150 nm, indicating the nanoporous structures. The MB m...

メチレンブルー担持ナノポーラスチタニア粒子への光照射に伴う一重項酸素生成能の評価

理化学・細胞生化学企業における研究開発分野でのロボットの活用実例 https://www.physical-computing.jp/page/51

To develop high‐performance and low‐cost microfluidic devices, heterogeneous bonding with cyclo‐olefin polymer (COP) and glass substrate was investigated by low‐pressure plasma using water vapor. COP and glass‐like substrate were bonded at room temperature under its own weight, and the bonding strength reached the breaking point of base material st...

To develop high performance and low cost microfluidic devices, heterogeneous bonding with cyclo-olefin polymer (COP) and glass substrate was investigated by low pressure plasma using water vapor. COP and glass-like substrate were bonded at room temperature under its own weight, and the bonding strength reached the breaking point of base material st...

Understanding nanoconfinement phenomena is necessary to develop nanofluidic technology platforms. One example of nanoconfinement phenomena are shifts in reaction equilibria toward reaction products in nanoconfined systems, which have been predicted theoretically and observed experimentally in DNA hybridization. Here we demonstrate a convection limi...

Affino-Electrophoresis in Nano/Micro Fluidic Devices for Diagnostic Application The emerging field of diagnostics for detecting protein biomarkers faces certain challenges like low abundance in human samples, lack of sensitivity and binding capacity, poor reproducibility, large sample volume requirement, high cost etc. To address these technical as...

The abnormality of single cell function is the trigger of many kinds of diseases such as infections and cancers. For the precise detection of such abnormality of cells, the development of analytical methods to quantify low-abundance proteins less than 104 molecules are highly required. Recently, nanofluidic devices have showed the possibility for u...

We have investigated antibody-antigen binding kinetic parameters in nanofluidic channels of differ-ent channel depths in order to design immunochemical reactions for nanofluidic immunoassay devices. We established a method to obtain antibody-antigen binding kinetic parameters in nanochannels by using the theoretical antigen binding model which igno...

To provide a fuel cell that can perform efficient power generation through a simple fuel supply. There is provided a fuel cell that generates electricity through progress of an oxidation-reduction reaction using an enzyme as a catalyst, the fuel cell including at least a fuel-vaporizing layer formed through vaporization of a fuel; an anode to which...

Provided is a fuel cell having a structure in which a cathode and an anode face each other with a proton conductor therebetween. In this fuel cell, an oxygen reductase or the like is immobilized on at least the cathode, and the cathode is composed of a material having pores therein such as porous carbon. In this fuel cell, the volume of water conta...

An objective of the present invention is to provide immunoassay microchips in which microstructures of beads having a sufficient reaction area were constructed within microchannels while suppressing flow path resistance, and to provide simple and highly-sensitive immunoassay methods for microsamples. The objective was achieved by immunoassay microc...

We report the first example of a liposome-based energy conversion system that is useful for entrapping enzymes and NAD coenzyme to accelerate multi-step enzymatic reactions. The liposome generates a much higher catalytic current compared with the non-liposome system, which is in good consistency with numerical simulations.

We present a new rapid and easy-to-use immunoassay chip which we have named the immuno-pillar chip. It has hydrogel pillars, fabricated inside a microchannel, with many antibody molecules immobilized onto 1 µm diameter polystyrene beads. To evaluate the chip performance, we applied it to the sandwich assay of C-reactive protein (CRP), α-fetoprotein...

We developed a rapid sample preparation method for the toxicological analysis of methamphetamine and amphetamine (the major metabolite of methamphetamine) in human hair by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), to facilitate fast screening and quantitation. Two milligrams of hair were mechanically micropulveri...

A UV excitation thermal-lens microscope (UV-TLM) with an excitation beam wavelength of 266 nm and liquid chromatograph (LC) were connected to build a new system (LC/UV-TLM) for the separation and highly sensitive label-free determination of biomolecules, such as peptides. A variation in the composition of the mobile phase with time, as in gradient...

A microchip-based semi-automated heterogeneous immunoassay was developed wherein a flow injection-like system and repeatable-use gel were employed. Microfluidics used a pump with highly accurate control of flow rate, two injector valves and a microchip. The results of a system suitability test based on dye injection for microfluidics including a th...

The pressure strength of microfluidics glass chips for high-pressure chemistry has been examined. Internal pressures up to 320bar have been measured, although variations are substantial. Long annealing steps at high temperatures did not show any improvement, but smoothening the powder blasted channel walls by isotropic etching did. Although macro c...

With a miniaturized (3 microL volume) fiber-optics based system for on-line measurement by UV/Vis spectroscopy, the reaction rate constants (at different pressures) and the activation volumes (deltaV(not =)) were determined for a nucleophilic aromatic substitution and an aza Diels-Alder reaction in a capillary microreactor.

We report on the use of time-resolved Fourier transform infrared spectroscopy (FT-IR) to study chemically induced conformational changes of proteins using the example of ubiquitin. For this purpose a micromachined mixer is coupled to a conventional IR transmission cell with a pathlength of 25 microm and operated in both the continuous and the stopp...

Time-resolved NMR spectroscopy is used to studychanges in protein conformation based on the elapsed time after a change in the solvent composition of a protein solution. The use of a micromixer and a continuous-flow method is described where the contents of two capillary flows are mixed rapidly, and then the NMR spectra of the combined flow are rec...

A major goal ofprotein dynamics studies is to obtain structural and kinetic information on intermediate states. Under the continuous flow, the conversion of a reaction time coordinate (time after mixing) to a stable (in time) distance coordinate well suited to spectroscopy that requires the accumulation of spectra, such as NMR and FT-IR. Although s...

Over the last few decades, the processes of miniaturization, integration, and automation have revolutionized the world of science and industry. Within a chemical reaction process the unit operations, mixing, heating, and cooling, can be regarded as key steps. In microreactors, enhanced heat and mass transport, due to small characteristic dimensions...

A method for evaluating a physiologically relevant ion selectivity of Ca2+ signaling pathways in biological cells based on a Ca(2+)-dependent on/off switch for cellular processes via calmodulin (CaM) chemistry is described. CaM serves as a primary ion receptor for Ca2+ and a given CaM-binding peptide as a target for a CaM-Ca2+ complex. Upon accommo...