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Chemosensor arrays have a great potential for on-site applications in real-world scenarios. However, to fabricate on chemosensor array a number of chemosensors are required to obtain various optical patterns for multianalyte detection. Herein, we propose a minimized chemosensor array composed of only two types of carboxylate-functionalized polythiophene derivatives for the detection of eight types of metal ions. Upon recognition of the metal ions, the polythiophenes exhibited changes in their fluorescence intensity and various spectral shifts. Although both chemosensors have the same polymer backbone and recognition moiety, only the difference in the number of methylene groups contributed to the difference in the fluorescence response patterns. Consequently, the metal ions in aqueous media were successfully discriminated qualitatively and quantitatively by the chemosensor microarray on the glass chip. This study offers an approach for achieving a minimized chemosensor array just by changing the alkyl chain lengths without the necessity for many receptors and reporters.

We herein report an extended gate-type organic thin-film transistor (OTFT)-based polyamine sensor and its application in pattern recognition. The extended-gate electrode was functionalized with a complex of copper(II) ions and 2-carboxymethylthio-5-mercapto-1,3,4-thiadiazole, which enabled the OTFT to respond to polyamines in an aqueous solution. Moreover, the responses of the OTFT-based sensor exhibited a cross-reactivity, implying its capability to detect multi-analytes. Thus, we performed pattern recognition against nine target polyamines (spermine, spermidine, trimethylenediamine, ethylenediamine, histamine, tryptamine, putrescine, cadaverine and 1,6-diaminohexane) in combination with linear discriminant analysis and successfully discriminated the analytes. Moreover, we achieved the quantification of spermine in a diluted fruit juice by using a support vector machine with high accuracy. Overall, the demonstration using the OTFT-based chemical sensor with pattern recognition revealed its potential for sensing polyamines in real samples.

We herein propose an easy-to-prepare mini-chemosensor array constructed by two-types of off-the-shelf coumarin dyes for simultaneous classification and quantification of sulfur-containing amino acids (SCAAs) (i.e., l-cysteine, l-cystine, l-homocysteine, glutathione, and glutathione disulfide). The detection mechanism of SCAAs relied on a coordination-based sensor array (CBSA) utilizing the competitive binding among the coumarin dye, a Zn

An artificial tongue that detects astringent components for a comprehensive evaluation of taste has not been established to date. Herein, we first propose fluorescent polythiophene (PT) derivatives (S1-S3) modified with 3-pyridinium boronic acid as supramolecular chemosensors for wine components including astringent procyanidin C1. After numerous attempts for the synthetic conditions, more than 95 mol % of the PT unit was modified with the pyridinium boronic acid moiety. To evaluate the PT derivatives as chemosensors of the artificial tongue, qualitative and quantitative analyses were performed with four types of wine components (i.e., sweet, sour, bitter, and astringent tastes) in combination with pattern recognition models. Notably, procyanidin C1 in the actual wine sample was successfully detected in a quantitative manner. In other words, we have established an authentic artificial tongue using PT based supramolecular chemosensors.

The current work proposes a novel determination method for enantiomeric excess (ee) in (mono- and di-) amines using molecular self-assembly. A pyridine-attached binaphthyl derivative ((R)-1) exhibits fluorescence responses based on imine formation between the aldehyde group of (R)-1 and target chiral amines (i.e. cyclohexane diamine (CHDA), 2-amino-1,2-diphenylethanol (ADPE), 1,2-diphenylethylenediamine (DPDA), 1-amino-2-indanol (AID), and leucinol) in the presence of zinc(II) ions (Zn2+). Because of the multi-optical responses which are derived from the variation of chiral complexes, pattern recognition-based discrimination (i.e. linear discriminant analysis (LDA)) has been achieved for five types of enantiomeric pairs of amines. Possessing such a discrimination capability in combination with data processing (LDA and an artificial neural network) allows accurate determination (prediction error < 1.8%) of the % ee of individual targets such as CHDA which is one of the main components of pharmaceutical drugs. The simple molecular self-assembled system enabled simultaneous multi-chiral discrimination and % ee determination of unknown samples.

Herein, a self-assembled colorimetric chemosensor array composed of off-the-shelf catechol dyes and a metal ion (i.e., Zn2+) has been used for the sulfur-containing amino acids (SCAAs; i.e., glutathione, glutathione disulfide,L–cysteine,DL–homocysteine, andL–cystine). The coordination binding–based chemosensor array (CBSA) fabricated by a competitive assay among SCAAs, Zn2+ions, and catechol dyes [i.e., pyrocatechol violet (PV), bromopyrogallol red (BPR), pyrogallol red (PR), and alizarin red S (ARS)] yielded fingerprint-like colorimetric changes. We succeeded in the qualification of SCAAs based on pattern recognition [i.e., a linear discrimination analysis (LDA)] with 100% correct classification accuracy. The semiquantification of reduced/oxidized forms of SCAAs was also performed based on LDA. Furthermore, we carried out a spike test of glutathione in food samples using the proposed chemosensor array with regression analysis. It is worth mentioning that we achieved a 91–110% recovery rate in real sample tests, which confirmed the accuracy of the constructed model. Thus, this study represents a step forward in assessing food freshness based on supramolecular analytical methods.

This work reports the design of a highly sensitive solid-state sensor device based on a water-gated organic thin-film transistor (WG-OTFT) for the selective detection of herbicide glyphosate (GlyP) in water. A competitive assay among carboxylate-functionalized polythiophene, Cu2+ , and GlyP was employed as a sensing mechanism. Molecular recognition phenomena and electrical double layer (EDL) (at the polymer/water interface) originated from the field-effect worked cooperatively to amplify the sensitivity for GlyP. The limit of detection of WG-OTFT (0.26 ppm) was lower than that of a fluorescence sensor chip (0.95 ppm) which is the conventional sensing method. In contrast to the previously reported insulated molecular wires to block interchain interactions, molecular aggregates under the field-effect has shown to be effective for amplification of sensitivity through "intra"- and "inter"-molecular wire effects. The opposite strategy in this study could pave the way for fully utilizing the sensing properties of polymer-based solid-state sensor devices.

Densities and viscosities of ethylene glycol - water and 1,3-propanediol - water binary mixtures have been measured over the whole composition range at 373.2 K and 473.2 K and at pressures up to 40 MPa. The excess molar volumes combined with partial molar volumes, and viscosity deviations have been calculated from the measurement data. The activation Gibbs free energy of viscous flow has been also evaluated from the density and viscosity data. These results were compared with the previously reported results of the monohydric alcohol - water mixtures with the same carbon numbers to discuss the effect of hydroxyl group and alkyl chain length on these properties in the wide range of temperature and pressure. The physical properties of the alcohol-water mixtures were strongly influenced by the molecular structure of the alcohol molecules under the studied conditions. In particular, the excess molar volumes and viscosity deviations showed very different behaviors for monohydric and dihydric alcohol - water mixtures.

During the past decades, colorimetric detection of sugars in a low-cost and user-friendly way has been a challenge. The current study introduces the first effort to develop a simplified colorimetri...

We herein propose a novel sensing strategy for biogenic amines using an electrolyte-gated polythiophene transistor. This ultra-low voltage operatable device responds to amines on the basis of the molecular recognition ability of a polythiophene pendant with a carboxy side-chain, which indicates that the sensing platform can contribute to the realisation of easy-to-fabricate and integrated chemical sensors.

Porous microneedles (MNs) are considered as promising methods to collect biosamples for painless and minimal invasive diagnosis of diseases such as diabetes. MNs have microscale size and interconnected pores and thus they can penetrate through epidermis without pain and collect interstitial fluid. These properties can be utilized for a new method for glucose sensing for diagnosis of diabetes. We thus focus on an integrated porous polydimethylsiloxane (PDMS)-based MNs (PDMS MN) with paper-based glucose sensor to realize the device for colorimetric diagnosis of diabetes. Disc-shaped PDMS MN layer consisting of 21 microneedles within an area of 1.7 cm2 was prepared. The microneedle showed a length of 800 μm and a porosity of 70 %. In this integrated system, porous media connects needles and sensor via a microfluidic channel. We successfully demonstrated the qualitative andquantitative analysis of glucose in the sample solution collected by porous MNs.

We have prepared a series of pyridinium-based gemini amphiphiles. They exhibit thermotropic liquid−crystalline behavior depending on their alkyl chain lengths and anion species. By adjusting the alkyl chain lengths and selecting suitable anions, we have obtained an ionic amphiphile that exhibits a normal-type bicontinuous cubic phase from 38 °C to 12 °C on cooling from an isotropic phase. In the bicontinuous cubic liquid−crystalline assembly, the pyridinium-based ionic parts align along a gyroid minimal surface forming a 3D continuous ionic domain while their ionophobic alkyl chains form 3D branched nanochannel networks. This ionic compound can form homogeneous mixtures with a lithium salt and the resultant mixtures keep the ability to form normal-type bicontinuous cubic phases. Ion conduction measurements have been performed for the mixtures on cooling. It has been revealed that the formation of the 3D branched ionophobic nanochannels does not disturb the ion conduction behavior in the ionic domain while it results in the conversion of the state of the mixtures from fluidic liquids to quasi-solids, namely highly viscous liquid crystals. Although the ionic conductivity of the mixtures is in the order of 10−7 S cm−1 at 40 °C, which is far lower than the values for practical use, the present material design has a potential to pave the way for developing advanced solid electrolytes consisting of two task-specific nanosegregated domains: One is an ionic liquid nano-domain with a 3D continuity for high ionic conductivity and the other is ionophobic nanochannel network domains for high mechanical strength.

Herein, a very simple colorimetric chemosensor array is reported for saccharides (D-glucose, D-fructose, D-xylose, D-galactose, D-mannose, L-rhamnose, and N-acetyl-D-gluosamine). While various types of chemosensors for saccharides have been investigated extensively to-this-date, tremendous additional efforts are still required on a regular basis for the syntheses of new chemosensors. Complicated syntheses would be a bottleneck, given that artificial receptor-based chemosensing systems are not so popular in comparison to biomaterial-based (e.g., enzyme-based) sensing systems. Toward this end, chemosensor array systems using molecular self-assembled materials can avoid the abovementioned synthetic efforts and achieve simultaneous qualitative and quantitative detection of a number of guest saccharides. Using a practical approach, we focus on an indicator displacement assay (IDA) to fabricate a chemosensor array for colorimetric saccharide sensing. On this basis, 3-nitrophenylboronic acid (3-NPBA) spontaneously reacts with catechol dyes such as alizarin red S (ARS), bromopyrogallol red (BPR), pyrogallol red (PR), and pyrocatechol violet (PV), and yields boronate ester derivatives with color changes. The addition of saccharides into the aqueous solution of the boronate esters induces color recovery owing to the higher binding affinity of 3-NPBA for saccharides, thus resulting in the release of dyes. By employing this system, we have succeeded in discriminating saccharides qualitatively and quantitatively with a classification success rate of 100%. Most importantly, our chemosensor array has been fabricated by only mixing low cost commercially available reagents in situ, which means that complicated synthetic processes are avoided for saccharide sensing. We believe this simple colorimetric assay that uses only commercially available reagents can create new, user-friendly supramolecular sensing pathways for saccharides.

Introduction Glyphosate (GlyP), a widely used herbicide in the agricultural field, was classified as a probable carcinogenic compound (Group 2A) by the International Agency for Research of Cancer (IARS) in 2015. Since then, the importance of the GlyP detection in aqueous media has increased in the field of environmental chemistry and clinical research. The concentration of GlyP in ground and tap water is strictly regulated. For example, the permissible limit for the GlyP concentration in drinking water set at 0.7 ppm in the United States. To-this-date, liquid chromatography (LC) is a common method to sensitively detect GlyP. However, the apparatuses of LC are expensive and require trained personnel, requesting the development of affordable, simple and sensitive sensors for the on-site GlyP detection. Thus, our research has focused on organic field-effect transistors (OFETs) as chemical sensing platforms, because of their low-cost and solution-processability, compact size, and mechanical flexibility[1]. Here, we report an OFET-based chemical sensor for the detection of GlyP in water. Design of the OFET sensor Polythiophene derivatives (PTs) have been widely studied and applied as organic semiconductors in OFET devices. Moreover, PTs has been employed for materials in chemical sensors because their optical and electrical properties can be tuned by introducing artificial receptors into their 3- and/or 4-positions as side chains. However, such OFET-based sensors based on PT attached with artificial receptors are still rare due to the typical high applied voltage (>|20V|) of the OFET which causes materials degradation. Thus we designed a water-gated OFET (WG-OFET) for chemical sensing applications, which could be operated at an ultra-low voltage ( Fabrication Method For the fabrication of the WG-OFET sensor device, we applied the side-gate structure (Figure 1). Compared to the conventional multi-stacked OFETs, the planar structure enables easy fabrication process. First, Au electrodes were selected as gate, source and drain, and were deposited on the same substrate. Then, an amorphous perfluoropolymer (Cytop) was used as the hydrophobic bank and patterned with oxygen plasma etching. Finally, a semiconducting polymer P3CPT was deposited onto the channel region by a drop-cast method. In order to prepare the dielectric layer made of aqueous media, 50 µL of 100 mM HEPES (4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid) buffer solution containing 100 mM NaCl was dropped onto the channel region and the gate terminal. After dropping the solution, 40 μM of a copper (II) ion was added into the HEPES buffer solution. The fabricated device was then allowed to stand for 10 minutes to stabilize the transistor characteristics. Results and Conclusions Figure 2 shows the transfer characteristics of the fabricated WG-OFET with the addition of the increasing amount of GlyP from 10 µM to 300 µM in a HEPES buffer solution at pH 7.4 at r.t. As expected, the changes of transfer characteristics were observed by increasing the concentration of GlyP, indicating that the GlyP removed the copper ion from the side-chain of P3CPT. From the low concentration part range of the titration isotherm, the limit of detection (LOD) was estimated to be 0.26 ppm. Notably, the obtained LOD value meets the criteria for the detection of GlyP in drinking water. Furthermore, the selectivity study as shown in Figure 3 demonstrated the highest response of the WG-OFET device to GlyP among the structurally similar carboxylates and phosphates, because of the strong binding affinity of GlyP for copper(Ⅱ) ions. We expect that this study is one step forward in the development of the OFET-based GlyP sensors for environmental and clinical assessment. References [1] R. Kubota, Y. Sasaki, T. Minamiki, T. Minami, Chemical Sensing Platforms Based on Organic Thin-Film Transistors Functionalized with Artificial Receptors, ACS Sens. 4 (2019) 2571–2587. doi:10.1021/acssensors.9b01114 [2] A. Giovannittia, D.T. Sbirceaa, S. Inalb, C. B. Nielsena, E. Bandielloe, D. A. Hanifif, M. Sessoloe, G. G. Malliarasb, I. McCullocha, and J. Rivnay, Controlling the mode of operation of organic transistors through side-chain engineering, Proc. Natl. Acad. Sci. USA. 113 (2016) 12017–12022. doi:10.1073/pnas.1608780113 [3] T. M. Swager, The Molecular Wire Approach to Sensory Signal Amplification, Acc. Chem. Res. 31 (1998) 201–207. doi:10.1021/ar9600502 Figure 1

First selective nitrate biosensor device based on an extended-gate type organic field-effect transistor (OFET) is reported. The fabricated sensor device consists of the extended-gate electrode functionalized by a nitrate reductase with a mediator (=a bipyridinium derivative) and an OFET-based transducer. The mechanism of the nitrate detection can be explained by an electron-relay on the extended-gate electrode, resulting in changes of the electric properties of the OFET. The detection limit of nitrate in water is estimated to be 45 ppb, which suggests that the sensitivity of our fabricated sensor is comparable to those of some conventional detection methods. As a practical application of the OFET sensor, the nitrate detection in diluted human saliva has been successfully demonstrated; the results agreed well with those by conventional colorimetric measurement. The advantages of OFETs are printability, mechanical flexibility, stretchability and disposability, meaning that the fabricated OFET could open up a new approach for low-cost electronic devices toward on-site detection of nitrate in aqueous media.

Herein, we report an organic field effect transistor (OFET) with an extended-gate modified by an artificial receptor for the detection of mercury(II) ions (Hg(2+)) in water. The sensor device is easy to fabricate, reusable, disposable, and portable. Thus OFET sensors could be applied for low-cost on-site detection of Hg(2+).

The critical roles of inflammation in the development of cancer have long been appreciated. A growing body of evidence supports the notion that infiltrates of inflammatory cells into tumor microenvironment influence the tumor progression by providing bioactive molecules including pro-inflammatory cytokines. Importantly, the increased number of mast cells within tumor microenvironment has been associated with a poor survival in cancer patients. Moreover, keratinocyte inflammation is known to be crucial for skin tumor development. The use of natural products to reduce inflammation in tumor microenvironment is gaining an interest, because of their reduced toxicity toward normal cells. In this study, we tested the effects of Tonggyu-tang (TGT) which is composed of 14 different herbal extracts on the activity of mast cells. We found that TGT significantly reduced the expression and production of inflammatory cytokines such as IL-4, IL-6, IL-8, and TNF-α in PMA and ionomycin- stimulated HMC-1 (human mast cell line-1). In an attempt to determine molecular mechanism underlying the inhibitory effects of TGT on cytokine expression, we revealed that TGT suppressed MAPK signaling pathway including ERK, p38, and JNK as well as NF-κB pathway, which are known to regulate inflammatory cytokine expression. Similar results were obtained from the LPS-stimulated HaCaT cells, immortalized human keratinocytes. Taken together, our results demonstrate that TGT suppresses inflammation by inhibiting the expression of pro-inflammatory cytokine in both mast cells and keratinocytes, thereby potentially leading to inhibition of tumor progression. Citation Format: Hyoin Kim, Seong-Gyu Ko, Yong Cheol Shin, Ji Hye Kim, Hye-Sook Seo, Tai Young Kim, Se Hyang Hong, Kangwook Lee, Jin Mo Ku, Myeong-Sun Kim, Yu-Jeong Choi, Soo-yeon Kang, Chunhoo Cheon, Youme Ko, Huang Ching Wen, Yui Sasaki, Sohyeon Kang. Tonggyu-tang, a traditional Korean medicine, suppresses inflammation, potential implications in tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4010. doi:10.1158/1538-7445.AM2017-4010