研究者詳細 - 金田　隆

Comparison of protein immobilization methods with covalent bonding on paper for paper-based enzyme-linked immunosorbent assay 査読

Yang Chen, Kaewta Danchana, Takashi Kaneta

Analytical and Bioanalytical Chemistry 416 ( 28 ) 6679 - 6686 2024年11月

担当区分：最終著者,　責任著者掲載種別：研究論文（学術雑誌）

In this study, two methods were examined to optimize the immobilization of antibodies on paper when conducting a paper-based enzyme-linked immunosorbent assay (P-ELISA). Human IgG, as a test-capture protein, was immobilized on paper via the formation of Schiff bases. Aldehyde groups were introduced onto the surface of the paper via two methods: NaIO4 and 3-aminopropyltriethoxysilane (APTS) with glutaraldehyde (APTS-glutaraldehyde). In the assay, horseradish peroxidase-conjugated anti-human IgG (HRP-anti-IgG) binds to the immobilized human IgG, and the colorimetric reaction of 3,3′,5,5′-tetramethylbenzyzine (TMB) produces a blue color in the presence of H2O2 and HRP-anti-IgG as a model analyte. The immobilization of human IgG, the enzymatic reaction conditions, and the reduction of the chemical bond between the paper surface and immobilized human IgG all were optimized in order to improve both the analytical performance and the stability. In addition, the thickness of the paper was examined to stabilize the analytical signal. Consequently, the APTS-glutaraldehyde method was superior to the NaIO4 method in terms of sensitivity and reproducibility. Conversely, the reduction of imine to amine with NaBH4 proved to exert only minimal influence on sensitivity and stability, although it tended to degrade reproducibility. We also found that thick paper was preferential when using P-ELISA because a rigid paper substrate prevents distortion of the paper surface that is often caused by repeated washing processes.

DOI： 10.1007/s00216-024-05575-4

Trace Analysis of Au in Carbonaceous Gold Ores by Inductively Coupled Plasma Optical Emission Spectrometry and Mass Spectrometry 査読

オンサイト環境分析のためのマイクロ流体ペーパー分析デバイス招待査読

梅田美華, 金田隆

分析化学 73 ( 9 ) 433 - 439 2024年9月

Ikumi Suyama, Diego M. Mendoza, Takashi Kaneta, Keiko Sasaki

MATERIALS TRANSACTIONS 65 ( 6 ) 644 - 651 2024年6月

Adsorption enrichment integrated with paper-based devices for detection of trace levels of hexavalent chromium in water samples 査読

Abdellah Muhammed, Ahmed Hussen, Takashi Kaneta

Analytical Sciences 40 ( 4 ) 709 - 717 2024年4月

掲載種別：研究論文（学術雑誌）

In the present study, a sensitive microfluidic paper-based analytical device (μ-PADs) integrated with adsorption enrichment procedure was developed to analyze Cr(VI) in water samples. The affecting factors, including pH and amounts of reagents were optimized. The limit of detection of 0.0015 mg L−1 and linear range of 0.005–2 mg L−1 were achieved with good intra- and inter-day precision of 5.1 and 7.6% RSD, respectively. The results obtained by the proposed method were validated by inductively coupled plasma-optical emission spectrometry (ICP-OES). The recoveries of the present method and ICP-OES were ranged from 96.3 to 109.0‬% and 106.0 to 109.7%, respectively. The two sets of (μ-PADs and ICP-OES) results were in a good agreement as paired t-test indicated no significant differences. The proposed method could be utilized for analyzing trace levels of Cr(VI) in water samples in the absence of conventional analytical instruments. Graphical abstract: (Figure presented.)

DOI： 10.1007/s44211-023-00504-4

Development of Pipetteless Paper-Based Analytical Devices with a Volume Gauge 査読

Fluorometric assay of laccase in mushroom extracts and comparisons with absorption spectrophotometry 査読

Jianchao Ren, Kaewta Danchana, Keiko Sasaki, Takashi Kaneta

Journal of Food Composition and Analysis 123 105627 - 105627 2023年10月

Separation and fractionation of glutamic acid and histidine via origami isoelectric focusing 査読

Kaewta Danchana, Nayu Yamashita, Mika I. Umeda, Takashi Kaneta

Journal of Chromatography A 1706 464247 - 464247 2023年9月

Kaewta Danchana, Hiroshi Iwasaki, Yada Thayawutthikun, Phoonthawee Saetear, Takashi Kaneta

ACS Omega 8 ( 12 ) 11213 - 11219 2023年3月

Multivariate Optimization of Operational Parameters in Microfluidic Paper-Based Analytical Devices for the Determination of Organophosphate and Carbamate Pesticides 査読

Sheleme Beshana, Ahmed Hussen, Seyoum Leta, Takashi Kaneta

Journal of Analytical Chemistry 78 ( 1 ) 25 - 34 2023年1月

Trace nickel analysis in water samples via paper-based devices coupled with co-precipitation 査読

A Muhammed, A Hussen, T Kaneta

South African Journal of Chemistry 77 1 - 7 2023年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Academy of Science of South Africa

A simple, fast, low-cost and sensitive microfluidic paper-based analytical device (u-PADs) integrated with the co-precipitation enrichment procedure was developed to analyse Ni(II) in tap and mineral water samples. The impacting factors, including pH, centrifugation (5 min at 4000 rpm), and amounts of reagents were optimized. The limit of detection of 0.009 mg L-1 and linear range of 0.03-2.00 mg L-1 were achieved with good intra- and inter-day precision (4.7 and 5.6% RSD, respectively). The recovery tests were conducted by spiking tap and mineral water samples and analyzed using the u-PADs after co-precipitation enrichment. The results obtained by the proposed method were validated by inductively coupled plasma-optical emission spectrometry (ICP-OES). The recoveries of the present method and ICP-OES were ranged from 92.4-106.8% and 92.9-97.2%, respectively. The two sets of (u-PADs and ICP-OES) results were in good agreement, as a paired t-test indicated no significant differences. The proposed method could be utilized for analyzing trace levels of Ni(II) in water samples in developing countries where the availability of conventional analytical instruments are significant problems.

DOI： 10.17159/0379-4350/2023/v77a01

Optical collection of extracellular vesicles in a culture medium enhanced by interactions with gold nanoparticles 査読

Yumeki Tani, Kenta Ochiai, Takashi Kaneta

Analytical Sciences 2022年11月

Dispersive liquid-liquid microextraction coupled with microfluidic paper-based analytical device for the determination of organophosphate and carbamate pesticides in the water sample. 査読国際誌

Sheleme Beshana, Ahmed Hussen, Seyoum Leta, Takashi Kaneta

Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 38 ( 10 ) 1359 - 1367 2022年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

A microfluidic paper-based analytical device (µ-PAD) is a promising new technology platform for the development of extremely low-cost sensing devices. However, it has low sensitivity that might not enable to measure maximum allowable concentration of various pollutants in the environment. In this study, a dispersive liquid-liquid microextraction (DLLME) was developed as a preconcentration method to enhance the sensitivity of the µ-PAD for trace analysis of selected pesticides. Four critical parameters (volume of n-hexane and acetone, extraction time, NaCl amount) that affect the efficiency of DLLME have been optimized using response surface methodology. An acceptable mean recovery of 79-97% and 83-93% was observed at 1 µg L-1 and 5 µg L-1 fortification level, respectively, with very good repeatability (2.2-6.01% RSD) and reproducibility (5.60-10.41% RSD). Very high enrichment factors ranging from 317 to 1471 were obtained. The limits of detection for the studied analytes were in the range of 0.18-0.41 µg L-1 which is much lower than the WHO limits of 5-50 µg L-1 for similar category of analytes. Therefore, by coupling DLLME with µ-PAD, a sensitivity that allows to detect environmental threat and also that surpassed most of the previous reports have been achieved in this study. This implies that the preconcentration step has a paramount contribution to address the sensitivity problem associated with µ-PAD.

DOI： 10.1007/s44211-022-00167-7

Microfluidic Paper Based Analytical Devices for the Detection of Carbamate Pesticides. 査読国際誌

Sheleme Beshana, Ahmed Hussen, Seyoum Leta, Takashi Kaneta

Bulletin of environmental contamination and toxicology 109 ( 2 ) 344 - 351 2022年8月

記述言語：英語掲載種別：研究論文（学術雑誌）

Microfluidic paper-based analytical devices (μ-PADs) are a new technology platform for the development of extremely low-cost sensing applications. In this study, μ-PADs has been developed for quantitative determination of carbamate pesticides. Key experimental parameters including concentration and volume of acetylcholinesterase, acetylthiocholine iodide and 5,5'-dithiobis-(2-nitrobenzoic acid), incubation time and image capturing time were systematically optimized. Under optimal conditions, the method showed wide range of linearity (0.25-16 mg/L), repeatability (4%-5% RSD) and intermediate precision (7%-10% RSD). Limit of detection was observed to be 0.4, 0.24 and 0.46 mg/L for carbaryl, carbosulfan and furathiocarb, respectively. An acceptable mean recovery (87% to 94%) was observed for the three pesticides at 1 mg/L fortification level. The results reveal that the developed method requires minimal reagents, simple and is easy to handle. It can be used for the quantification of carbamate pesticides in resource limited laboratories without the need for the conventional analytical instruments.

DOI： 10.1007/s00128-022-03533-3

Determination of glutamate using paper-based microfluidic devices with colorimetric detection for food samples 査読

Kaewta Danchana, Hiroshi Iwasaki, Kenta Ochiai, Haruka Namba, Takashi Kaneta

Microchemical Journal 179 107513 - 107513 2022年8月

担当区分：最終著者,　責任著者掲載種別：研究論文（学術雑誌）出版者・発行元：Elsevier BV

A paper-based device (PAD) capable of colorimetric detection was developed to determine the presence of glutamate in various food samples. The PAD employs an enzymatic reaction with glutamate followed by an oxidation reaction with N-benzoyl leucomethylene blue (BLMB) in the presence of horseradish peroxidase. The designed PAD consists of a sample introduction zone connected to a channel that transports a sample solution to three detection zones. The detection zones contain pre-deposited reagents: glutamate oxidase, horseradish peroxidase, BLMB, a phosphate buffer, and poly(acrylic acid). The PAD is perpendicularly immersed into a sample solution and bent at a right angle using a 3D-printed holder to allow the sample to simultaneously flow into three different detection zones. When the PAD is immersed into a sample containing glutamate, glutamate oxidase produces hydrogen peroxide, which changes the pale blue color of BLMB to a deep blue color in the presence of horseradish peroxidase. Under the optimum conditions, the calibration curve between the logarithm of the glutamate concentrations and the color intensity was linear within a range of from 5 × 10-6 mol L-1 to 10-2 and with a correlation coefficient of 0.994. Using this system, the PAD successfully determined glutamate in soup stocks, sauces, snacks, and tomato juice without the need of complicated sample pretreatment. These results agreed with those of a commercially available glutamate assay kit, which was employed as a certification method (tstat = 1.95, tcrit = 2.57). The developed PAD is simple, easy to fabricate, portable, and could be used outside of equipped laboratories to determine the presence of glutamate in food samples.

DOI： 10.1016/j.microc.2022.107513

Dip-and-Read, Organic Solvent-Compatible, Paper-Based Analytical Devices Equipped with Chromatographic Separation for Indole Analysis in Shrimp. 査読国際誌

Sasikarn Seetasang, Takashi Kaneta

ACS sensors 7 ( 4 ) 1194 - 1200 2022年4月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

We developed an organic solvent-compatible paper-based analytical device (PAD) for the quantitative analysis of indole, which is an indicator of shrimp freshness. Although indole is insoluble in water, ethyl acetate is a suitable solvent to dissolve and extract indole from shrimp. The PADs are fabricated using a cutting method that allows the use of an organic solvent because no hydrophobic barrier is needed to form fluidic channels. Ehrlich's reagent consists of 4-(dimethylamino)benzaldehyde and p-dimethylaminobenzaldehyde and was deposited onto the reaction zone of the PAD followed by lamination to prevent evaporation of the ethyl acetate. Samples are introduced into the PAD via immersion in organic sample solutions. When the PAD is immersed into an indole solution of ethyl acetate in a closed bottle, the sample solution penetrates the channel of the PAD and successively flows into the detection zone to form a hydrophilic colored product. The PADs provide a linear relationship between the logarithm of the indole concentration and the color intensity within a range of 1.0-20 ppm with correlation coefficients of r2 > 0.99. The limits of detection and quantification are 0.36 and 0.71 ppm, respectively. Relative standard deviations for both the intraday (n = 2) and interday (n = 3) precision were less than 2.5%. In the indole analysis of shrimp, the PADs separated the interfering orange-colored astaxanthin in the extract from the colored product of indole via the paper chromatographic principle. We used the PADs to investigate the degradation of shrimp, and the results showed a rapid increase in the indole level after 7 days. High-performance liquid chromatography verified the accuracy of the PADs by showing good agreement with the obtained indole levels.

DOI： 10.1021/acssensors.2c00300

N-Benzoyl leucomethylene blue as a novel substrate for the assays of horseradish peroxidase by spectrophotometry and capillary electrophoresis-laser-induced fluorometry. 査読国際誌

Jianchao Ren, Takashi Kaneta

Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 38 ( 4 ) 651 - 655 2022年4月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Horseradish peroxidase (HRP) is an enzyme that is frequently employed in various assays because HRP catalyzes the oxidation reactions of chromogenic and fluorogenic compounds to produce chromophores and fluorophores, respectively. The results of this study show that N-benzoyl leucomethylene blue (BLMB) is an excellent substrate for enzyme assay using HRP. In the presence of hydrogen peroxide (H2O2), HRP catalyzed an oxidation reaction of BLMB that produced methylene blue with a deep blue color. Thus, absorption spectrophotometry and capillary electrophoresis-laser-induced fluorometry (CE-LIF) could be used to easily determine the produced methylene blue. Under the optimum conditions, absorption spectrophotometry showed a linear calibration curve that ranged from 25 to 500 µg mL-1. The reaction conditions were also applicable to CE-LIF, showing a linear range of from 25 to 500 µg mL-1 with limits of detection and quantification at 2 and 6 µg mL-1, respectively.

DOI： 10.1007/s44211-022-00078-7

Microfluidic paper-based analytical devices coupled with coprecipitation enrichment show improved trace analysis of copper ions in water samples. 査読国際誌

Abdellah Muhammed, Ahmed Hussen, Takashi Kaneta

Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 38 ( 1 ) 123 - 130 2022年1月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

The present study focused on improving sensitivity to trace levels of Cu(II) by subjecting microfluidic paper-based analytical devices (μ-PADs) to a preconcentration process via coprecipitation using aluminum hydroxide. The experimental conditions were optimized for the pH of the coprecipitation, centrifugation, and amounts of reagents that were deposited onto µ-PADs for the Cu(II) assay. The resultant limit of detection reached as low as 0.003 mg L-1 with a linear range of 0.01-2.00 mg L-1. The relative standard deviations for intra- and inter-day precision were 3.2 and 4.6%, respectively (n = 9). Spiked water samples were analyzed using the μ-PADs after coprecipitation preconcentration. The results were verified by comparing them with those of inductively coupled plasma-optical emission spectrometry (ICP-OES). Recoveries ranged from 97.1 to 104% and from 98.7 to 105% using the present method and ICP-OES, respectively. These results suggest that the simple, highly sensitive, and inexpensive proposed method would be helpful for analyzing trace levels of Cu(II) in water samples in poorly equipped laboratories.

DOI： 10.2116/analsci.21P215

Portable two-color photometer based on paired light emitter detector diodes and its application to the determination of paraquat and diquat 査読

Sasikarn Seetasang, Takashi Kaneta

Microchemical Journal 171 2021年12月

担当区分：最終著者,　責任著者掲載種別：研究論文（学術雑誌）

Here we describe a methodology for the determination of paraquat and diquat using a newly developed portable photometer equipped with two colors of paired light emitter detector diodes (PEDD). The colorimetric measurements employed in this work include the redox reactions between 1) dithiothreitol and diquat to produce the red color characteristic of a diquat radical and 2) between sodium dithionite and either diquat or paraquat that results in the green and blue colors of diquat and paraquat radicals, respectively. The addition of sodium dithionite or dithiothreitol in a solid-state provides reproducible absorbance of the radicals, prevents decomposition of the reagents in a solution, and simplifies handling of the reagents. The diquat radical produced by dithiothreitol (λmax = 495 nm) was successfully detected by using a pair of blue LEDs with a maximum emission wavelength at 472 nm while the radicals of paraquat (λmax = 603 nm) and diquat (λmax = 771 nm) reduced by sodium dithionite were measured by a pair of orange LEDs with a maximum emission wavelength of 609 nm. The proposed method consists of measuring diquat radicals at 472 nm, estimating the absorbance of diquat radicals at 609 nm, and subtracting the estimated absorbance of diquat radicals from the total absorbance at 609 nm to determine paraquat radicals. The developed method yielded examples of excellent linear regression (r2) of more than 0.99 in three calibration curves of the radicals measured at 472 nm for diquat radicals and measured at 609 nm for both diquat and paraquat radicals. The intra-day (n = 3) and inter-day (n = 3) precision of three calibration curves were less than or equal to 5%. By comparison with the standard method of high-performance liquid chromatography, the reliability of the proposed method was proven via the analysis of paraquat and diquat radicals in a commercially available herbicide.

DOI： 10.1016/j.microc.2021.106777

Speciation of chromium in water samples using microfluidic paper-based analytical devices with online oxidation of trivalent chromium 査読

Abdellah Muhammed, Ahmed Hussen, Takashi Kaneta

ANALYTICAL AND BIOANALYTICAL CHEMISTRY 413 ( 12 ) 3339 - 3347 2021年5月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER HEIDELBERG

Speciation of chromium (Cr) was demonstrated using microfluidic paper-based analytical devices (mu-PADs) that permit the colorimetric determination of hexavalent chromium (Cr(VI)) and trivalent chromium (Cr(III)) via online oxidation. The mu-PADs consist of left and right channels that allow the simultaneous measurements of Cr(VI) and total Cr based on the colorimetric reaction of Cr(VI) with 1,5-diphenylcarbazide (DPC). For the determination of Cr(VI), a sample solution was directly reacted with DPC in the left channels whereas total Cr was determined in the right channels, which permitted online oxidation in the pretreatment zone containing cerium (IV) (Ce(IV)) followed by a colorimetric reaction with DPC. We found that the online oxidation of Cr(III) proceeded 100% whereas Ce(IV) inhibited the reaction of Cr(VI) with DPC. Therefore, speciation can be achieved by measuring the Cr(VI) and total Cr in the left and right channels followed by the subtraction of Cr(VI) from total Cr. The limits of detection and quantification were 0.008 and 0.02 mg L-1 for Cr(VI) and 0.07 and 0.1 mg L-1 for Cr(III) or total Cr, respectively. The linear dynamic ranges were 0.02-100 mg L-1 and 0.1-60 mg L-1 for Cr(VI) and Cr(III), respectively. The RSDs were less than 7.5%. The results obtained using mu-PADs were in good agreement with those obtained via ICP-OES with recoveries of 92-108% for Cr(III) and 108-110% for Cr (VI) using mu-PADs, and 106-110% for total Cr using ICP-OES. Thus, the mu-PADs could potentially be utilized for the speciation of chromium in developing countries where environmental pollution and the availability of sophisticated instruments are significant problems.

DOI： 10.1007/s00216-021-03274-y

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