bluuebunny/crossref_metadata_2025_split huggingface dataset:
Room Temperature Synthesis and Fluorescence Visualization Sensing of Inorganic Perovskite Quantum Dots
Authors: Qiu Zhiwei , Chen Yuzhu , Zhang Yu , Gong Houjian , Zeng Jingbin 
Published: May 2020

Perovskite Quantum Dots are widely used in the field of optoelectronics because of their good electron mobility.[1] As a fluorescent nanomaterial, they also have many excellent properties, such as high fluorescence quantum efficiency, emission wavelength coverage visible spectrum, narrow half-width and small Stokes shift, etc.[2] The synthesis of all-inorganic perovskite is currently commonly carried out by oil phase thermal injection.[3] This method is cumbersome and requires strict equipment and experimental conditions. In this paper, a simple method for the rapid synthesis of CsPbX3 (X=Cl-, Br-, I-) fluorescent quantum dots was explored. The high-quality fluorescent quantum dot solution was synthesized in one step by the principle of ligand-assisted coprecipitation at room temperature. According to the related characterization work, the product has excellent cubic crystal phase structure and strong fluorescence intensity.
Furthermore, this work focuses on the application of fluorescence colorimetric sensing of perovskite quantum dots and solving the problem of water annihilation. Fluorescence visualization colorimetric detection of Cl- and I- was successfully achieved by using heterogeneous halogen exchange to induce wavelength shift detection; Then, using the hydrophobic properties of PDMS, the products synthesized at room temperature as described above were coated with PDMS silicon film, and the stable existence of fluorescent quantum dots under water conditions was successfully realized, which improved the application range of perovskite fluorescent materials.

Figure 1
(Invited) Nanomaterials and Smart-Phone Based Biosensors for Point-of-Care Diagnostics
Authors: Du Dan , Lin Yuehe 
Published: May 2020

In this talk, I will give an overview of recent works in our laboratory for hand-held biosensing devices based on smartphone and 3D-printing. We have synthesized various functional nanomaterials such as organic-inorganic hybrid nanoflowers, carbon quantum dots, single-atom nanozymes for signal enhancement in bioassays. Applications of these smartphone based nanosensors for biomedical diagnostics and food safety monitoring will be discussed.
References:
1. L. Jiao, H. Yan, Y. Wu, W. Gu, C. Zhu, D. Du, Y. Lin. When Nanozymes Meet Single-Atom Catalysis. Angew. Chem. Int. Ed. 2019, doi.org/10.1002/ange.201905645
2. C. Zhu, S. Fu, Q. Shi, D. Du, Y. Lin. Single-Atom Electrocatalysts. Angew. Chem. Int. Ed. 2017, 56, 13944-13960.
3. N. Cheng, J. Li, D. Liu, Y. Lin, D. Du. Single-Atom Nanozyme Based on Nanoengineered Fe-N-C Catalyst with Superior Peroxidase-Like Activity for Ultrasensitive Bioassays. Small 2019, 1901485.
4. X. Niu, Q. Shi, W. Zhu, D. Liu, H. Tian, S. Fu, N. Cheng, S. Li, J. N Smith, D. Du, Y. Lin, Unprecedented peroxidase-mimicking activity of single-atom nanozyme with atomically dispersed Fe-Nx moieties hosted by MOF derived porous carbon. Biosensors & Bioelectronics 2019, 142, 111495.
5. W. Wen, D. Du, Y. Lin. Recent Advance in Electrochemical Immunosensor. Analytical Chemistry 2017, 89, 138-156.
6. C. Zhu, G. Yang, H. Li, D. Du, Y. Lin. Electrochemical Sensors and Biosensors Based on Nanomaterials and Nanostructures. Analytical Chemistry 2015, 87, 230-249.
7. R. Ye, C. Zhu, Y. Song, Q. Lu, X. Ge, X. Yang, M. Zhu, D. Du, H. Li, Y. Lin, Bioinspired Synthesis of All‐in‐One Organic–Inorganic Hybrid Nanoflowers Combined with a Handheld pH Meter for On‐Site Detection of Food Pathogen. Small 2016, 12, 3094-3100.
8. Y. Wang, M. Zeinhom, M. Yang, R. Sun, S. Wang, J. Smith, C. Timchalk, L. Li, Y. Lin, D. Du, A 3D-Printed, Portable, Optical-Sensing Platform for Smartphones Capable of Detecting the Herbicide 2, 4-Dichlorophenoxyacetic Acid. Analytical Chemistry 2017, 89, 9339-9346.
9. N. Cheng, Y. Song, M. Zeinhom, Y. Chang, L. Sheng, H. Li, D. Du, L. Li, M. Zhu, Y. Luo, W. Xu, Y. Lin, Nanozyme mediated dual-immunoassay integrated with smartphone for use in simultaneous detection of pathogens. ACS Applied Materials & Interfaces 2017, DOI: 10.1021/acsami.7b12734
Depositing Highly Uniform Au Nanoparticles on the Surface of High-Curvature Nanofibers for SERS Optophysiology
Authors: Zhao Xingjuan , Wallace Gregory Q , Bazuin Geraldine C. , Masson Jean-François 
Published: May 2020

Nanofibers as biosensors have attracted great attention due to its facile removal from the biosystem after a period of intra- or extracellular measurements and site-specific measurement among others. The application of nanofibers covered with Au nanoparticles as SERS sensor circumvents the aggregation and accumulation of Au nanoparticles in vitro or in vivo, in addition to the greater Raman enhancement of signal than on planar surface. To achieve this, our group has reported a block copolymer-template method to deposit Au nanoparticles on the highly curved surface of nanofibers.[1] Here the versatility of this strategy is demonstrated by depositing nanoparticles with the different dimensions or shapes and varying the density of Au nanoparticles on the surface of the nanofibers. To the best of our knowledge, we believe this is the first work to show how to obtain such highly uniform distribution of anistropic nanoparticles on the surface of high-curvature nanofibers. Among all the nanosensors studied in this work, the label-free nanofibers covered with Au nanostars with shorter branches shows the biggest enhancement, which could detect neurotransmitter secretion such as dopamine with moderate laser power and low integration time. Furthermore, measurement of pH in the cell microenvironment and pH gradient in the cell medium can be realized by our biosensors as well. The rapid pH response to the external environment makes it very promising for the application of the dynamic pH measurement in vitro or in vivo. In addition to SERS sensing, these highly uniform nanosensors have other far-reaching implications, including medical diagnostics, therapeutics and so on.
[1] Zhu, H., Lussier, F., Ducrot, C., Bourque, M. J., Spatz, J. P., Cui, W., Yu, L., Peng, W., Trudeau, L. E., Bazuin, C. G. and Masson, J. F., ACS Appl. Mater. Interfaces, 2019, DOI: 10.1021/acsami.8b19161.

Figure 1
Strategies for Chemical Sensing Using High Purity Semiconducting Single-Walled Carbon Nanotube Electronic Devices
Authors: Lapointe François 
Published: May 2020

Semiconducting single-walled carbon nanotubes (sc-SWCNTs) are attractive in chemical sensing [1] because of their peculiarities: As they present a single atom-thick wall and a quasi 1D form factor, sc-SWCNTs are especially sensitive to their surroundings’ electrostatics. Moreover, their band gap of approximately 1 eV is much greater than room-temperature thermal energy while being in a convenient range for electronic applications. Also, their electronic structure exhibits van Hove singularities (sharp spikes in the density of states) that drastically alters their conductivity and optical properties when charge carriers are injected. Although sc-SWCNT electronic devices are very sensitive, they lack in selectivity and they usually need to be functionalized to implement a lock-and-key detection mechanism.
In this talk, we will present various strategies for chemical sensing using enriched sc-SWCNTs. We will discuss the advantages and disadvantages of using sc-SWCNTs in electronic chemical sensing devices. Sub-ppm ammonia sensing will be demonstrated using a sc-SWCNT material wrapped with a decomposable polymer in a chemiresistor configuration. [2] Also using chemiresistors, CO2 detection has been achieved by designing a SWCNT-wrapping polymer with specific interactions. Finally, we will present a strategy to differentiate the response of sensor elements to a variety of volatile analytes by changing the polymer gate dielectrics in a three-terminal bottom gate chemitransistor configuration. [3] This methodology opens the way to the implementation of sc-SWCNT-based chemitransistors in a printed cross-reactive sensor array.

References

[1] Schroeder, V. et al. Carbon Nanotube Chemical Sensors. Chem. Rev.
119, 599–663 (2019)
[2] Li, Z. et al. Decomposable s-Tetrazine Copolymer Enables Single-Walled Carbon Nanotube Thin Film Transistors and Sensors with Improved Sensitivity. Adv. Funct. Mater. 1705568 (2018)
[3] Lapointe, F. et al. Carbon Nanotube Transistors as Gas Sensors: Response Differentiation using Polymer Gate Dielectrics. AC
S Appl. Polym. Mater.
https://doi.org/10.1021/acsapm.9b00707 (2019) – Accepted for publication
Synthesis of Psi/CuO/Cu2o Heterostructure for NH3 Vapor Detection at Room Temperature
Authors: Bouachma Soraya , Gabouze Noureddine 
Published: May 2020

In this paper, we demonstrate the use of the heterostructure porous silicon PSi-n/CuO-p/Cu2O-n as an alternative structure for an efficient gas sensor for NH3 sensing. The porous silicon PSi was prepared using an electrochemical method and utilized as a substrate. Then, CuO homogeneous thin films were synthesized by thermal evaporation/oxidation on the pre-prepared PSi substrate, on which a uniform layer of Cu2O is deposited by electrodeposition method.
The structural, morphological and optical characterizations of the obtained CuO and Cu2O films were carried out by XRD, SEM, FTIR, UV spectroscopy and contact angle measurements. Likewise, the electrical properties of CuO-p/Cu2O-n thin films, deposited on PSi-n, were studied by current-voltage (I-V) measurements at room temperature, within the sandwich (semiconductor/oxide/oxide) configuration. The NH3 gas sensing characteristics: response/recovery time, sensitivity and repeatability, were evaluated and tested at different gas concentrations at room temperature, allowing the determination of the different parameters of the heterojunction PSi/CuO/Cu2O.
These results indicated that the PSi/CuO/Cu2O structure is a promising candidate for reliable high-performance NH3 gas sensors at room temperature, with a very high sensitivity to NH3 (80%) and with an extremely fast response time of the order of 1 second. These sensing performances enhancements at room temperature are due to the high surface area to volume ratio of PSi and the use of PSi/CuO/Cu2O heterostructure. The prospective sensing mechanism of the presented sensor has been discussed.
A study on Gas sensing Properties and Reaction Mechanism of Au@SnO2 Core-shell Structure Nanoparticles to H2S Gas
Authors: Yu Yeon-Tae 
Published: May 2020

The H2S is a toxic and malodorous gas produced from coal mine, natural gas manufacturing processes, and wastewater treatment plants. Due to increased environmental concern, there is an increasing demand for semiconductor gas sensors that are selective and responsive towards H2S gas.
SnO2 has been known as a representative semiconductor gas sensing material because of chemical stability and high electron mobility. However SnO2 has a problem that H2S gas doesn’t detached after adsorbing on the surface on SnO2. To solve this problem, the use of noble metal catalysts has been suggested. Au nanoparticles (NPs) are reported to be a good catalyst for the H2S oxidation reaction. To investigate the effects of Au NPs on H2S adsorption and desorption, Au@SnO2 core-shell NPs were applied as a sensing material.
In this study, Au@SnO2 core-shell NPs has been synthesized by microwave-assisted hydrothermal method. Au@SnO2 core-shell NPs were calcined at various temperatures (350°C ~ 550°C) to control the surface morphology and crystallinity of SnO2 shell, and their gas sensing property were investigated towards H2S gas (2 ppm to 100 ppm). Based on the results of the sensing test of Au@SnO2 core-shell NPs, we examined the effect of Au NPs on H2S adsorption and desorption.
The Au@SnO2 core-shell structure NPs were successfully synthesized by microwave-assisted hydrothermal method, and the particle size was 26-30 nm and the shell thickness of SnO2 shell layer was 14-18 nm. The highest sensing responses of pure SnO2 and Au@SnO2 core-shell NPs showed at the working temperature of 200°C, the responses value to 100 ppm H2S gas were 4,748 and 517, respectively. The optimum working temperature for Au@SnO2 core-shell NPs for detecting H2S gas was at 300°C because the gas sensing response showed relatively high as compared to pure SnO2 and the recovery rate was the highest value. Moreover, the selectivity of H2S toward CO, CH4, C2H5OH gases appeared at this working temperature. The reason why Au@SnO2 core-shell NPs selectively reacted with H2S gas at 300°C was due to the catalytic activity of Au core for H2S oxidation reaction.
Keywords: Au@SnO2, nanoparticle, semiconductor gas sensor, H2S gas, adsorption
Supercritical Fluids Synthesis of Nanocatlayst-Decorated Nanocarbons for Amprometric Hydrogen Sensing
Authors: Liao Jin-Yi , Wang Shih-Han , Yang Cheng-Kang 
Published: May 2020

It is getting more and more attention on the breathing gas monitoring since it is a non-invasive technique. Hydrogen gas is an important biomarker of gastrointestinal diseases in exhaled gas. The elevated hydrogen level correlated to gastrointestinal diseases. The average hydrogen concentration for healthy people is less than 20 ppm[1]. In this study, the structure of fuel cell was adapted to develop a highly sensitive electrochemical hydrogen sensor which could be apply for breath gas analysis. In the previous studies, platinum groups metals (PGM) were extensively applied for hydrogen oxidation reaction[2]. A serious platinum group metals and non-PGM metals, such as platinum, iridium and palladium, and non-PGM, Cu, were decorated on the nanocarbons surface to use as the working electrode. The nanometal catalysts were decorated on uniformly utilizing supercritical fluids technique. X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and in-situ Fourier transform infrared spectroscopy were used to characterize the microstructure, surface morphology, chemical structure and sensing mechanism. The electrochemical properties of the electrodes were analyzed. The amprometric sensing performance of the PtCu decorated nanocarbon showed high sensitivity. The sensing range was from 0-100 ppm and the lower detection limit was 0.52 ppm. Potential interferences, such some reducing gases and VOC were tested as well. This highly sensitive hydrogen sensor is suitable for environmental and health applications.
References
[1] A. Eisenmann, A. Amann, M. Said, B. Datta, M. Ledochowski, J. Breath Res 2, 046002 (2008); doi: 10.1088/1752-7155/2/4/046002
[2] E. S. Davydova, S. Mukerjee, F. Jaouen, and D. R. Dekel, ACS Catal 8, 6665-6690(2018); doi: 10.1021/acscatal.8b00689
Amperometric Simultaneous Measurement of NO, CO and H2s during Induced Focal Seizures Using a Triple Microsensor
Authors: Seo Sunghwa , Lee Youngmi 
Published: May 2020

In these days, nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) are well known as endogenous neurotransmitters in mammalian cells and have been studied regarding their mechanisms playing the roles as neurotransmitters in vivo. However, the actual relations among these three gases in transmitting neuronal signals in brain are still controversial and therefore, direct real-time concurrent analysis of NO, CO and H2S is required to clarify their biological relations.
In current presentation, we demonstrate the fabrication of a NO/CO/H2S triple sensor and the simultaneous real-time measurements of these three gases at a rat brain surface under acute seizure using the sensor. This sensor consists of three platinum (Pt) disk working electrodes: 50, 76 and 50-μm diameter Pt microdisks (denoted as WE1, 2 and 3, respectively). The Pt disks of WE 2 and 3 are etched electrochemically and further electrodeposited with metal nanoparticles (Ru and Au, respectively). Then, the surface of each electrode is covered with a different intended target-selective membrane. These membranes are adapted for the selectivity to the gases excluding other biological interferences. Finally, these electrodes are applied with different optimized potentials, respectively to cause the oxidation of individual target gases and the oxidation currents are monitored. The developed NO/CO/H2S triple sensor is characterized in terms of its performances such as sensitivity, selectivity, etc. The sensors is utilized to monitor the concentration changes of NO, CO and H2S gases at a rat brain cortex under a seizure induced with administration of 4-acetamidophenol (AP). The actual patterns of the real-time concurrent changes of these gases were carefully investigated along with local field potential (LFP) signal changes. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT& Future Planning (NRF-2017R1A2A2A14001137).
Mxene Nanosheets Preparation Sensitive Film for QCM Humidity Sensor
Authors: Xu Jiaqiang , Li Runlong 
Published: May 2020

Fast, sensitive and stable detection of humidity is essential. In this paper, a 2D ultra-thin nanosheet Mxene was used as the material to form a sensitive film to construct the quartz crystal microbalance (QCM) humidity sensor by drop coating method. The element A in the MAX phase was dislodged by a simple liquid phase etching method. The morphology and composition of Mxene were studied by means of a series characterization methods, it was found the sample take on a ultrathin grapheme-like nanosheet. The test results show that the humidity sensor has 12.8Hz/% RH sensitivity, 6s and 2s (@ 90%)response/recovery time, maximum humidity hysteresis of 1.16%RH, good stability and selectivity. Finally, the adsorption enthalpy of water molecules on the surface of Mxene was explored by DFT calculation. It was found that residual F- played an important role in humitity sensing

Introduction:

The new two-dimensional (2D) material Mxene has been widely used in energy storage , battery , catalysis , electromagnetic shielding and other directions since it was discovered by the research team of Professor Yury Gogotsi of Drexel University in 2011.Ti3C2Tx has good electronic conductivity and hydrophilicity, it is the most widely studied and mature of all Mxenes. This work combines Mxene-Ti3C2Tx with the QCM test platform to further enhance the application of Mxene materials on humidity sensors.
By optimizing the method in the previous literature, the Ti3AlC2 powder was etched in LiF / HCl solution to remove the Al element, some post-treatment such us ultrasonic was carry out to obtain a single-layer Ti3C2Tx solution that can be used to directly prepare the device. The obtained samples were characterized by XRD, SEM, TEM, EDS, XPS and BET, etc, it was found that Mxene with a large specific surface area has a good single-layer sheet structure, and the surface contains a large number of -OH, -O, -F functional groups. This single-layer sheet structure with large specific surface area and abundant active sites is more conducive to the adsorption of water molecules. By detecting the relative humidity of 11.3% - 97.3% shows that the sensor with the best performance has excellent sensitivity of 12.8Hz/% RH, 6s and 2s (@ 90%) rapid response/recovery time, maximum humidity hysteresis of 1.16%RH, good short-term repeatability, long-term stability, and excellent cross-sensitivity. Through characterization and simulation, it is found that -F functional group plays a certain role in the excellent humidity sensitivity. This not only provides a new possibility for the application of 2D materials in humidity sensor, but also widens the application of Mxene materials in sensor field.

Figure 1
Host-Guest Complex for Heparin Binding and Sensing
Authors: Välimäki Salla , Beyeh Ngong Kodiah , Linko Veikko , Ras Robin , Kostiainen Mauri 
Published: May 2020

Heparin is a naturally occurring highly charged polyanion and a well-known anticoagulant widely used in surgical practice.[1] More specifically, it is a negatively charged sulfated polysaccharide belonging to the group of glycosaminoglycans (Scheme 1). The anticoagulant effect of heparin is based on its ability to activate antithrombin-III, which, subsequently, inactivates vital coagulation cascade substance such as thrombin and factor Xa consequently preventing fibrin and clot formation.[2] To balance and neutralize heparin dosing, a heparin inhibitor is needed, and commonly, arginine-rich protein protamine sulfate (PS) is used for this purpose.[3] However, in recent years there has been an interest to investigate alternatives for protamine due to its adverse effects like hypotension and serious allergic reactions.[4]
In this study, a host-guest complex capable in selective heparin binding and sensing is presented.[5] Heparin binding affinity was studied in solution with a variety of polycationic macrocyclic hosts, a pillar[5]arene and multiple resorcin[4]arenes, by dynamic light scattering, dye displacement assay, isothermal titration calorimetry, and anti-Xa assay. The measurements reveal the significant importance of multivalency in the electrostatic host-heparin binding in competitive, application-relevant media. Additionally, to monitor heparin concentration, a host-guest indicator displacement assay was performed by following the free and bound state of methyl orange dye in UV-Vis spectroscopic experiments. Furthermore, this colorimetric sensing based on the tertiary host-guest-heparin supramolecular assembly was utilized in the construction of a calibration curve in a range of blood plasma concentrations.

References

[1] B. Casu, A. Naggi, G. Torri, Re-visiting the structure of heparin, Carbohydr. Res., 403 (2015), 60–68. https://doi.org/10.1016/j.carres.2014.06.023

[2] J. Hirsh, T.E. Warkentin, S.G. Shaughnessy, S.S. Anand, J.L. Halperin, R. Raschke, C. Granger, E.M. Ohman, J.E. Dalen, Heparin and Low-Molecular-Weight Heparin Mechanisms of Action, Pharmacokinetics, Dosing, Monitoring, Efficacy, and Safety, Chest, 119, (2001), 64S–94S. https://doi.org/10.1378/chest.119.1_suppl.64S.
[3] S.M. Bromfield, E. Wilde and D.K. Smith, Heparin sensing and binding – taking supramolecular chemistry towards clinical applications, Chem. Soc. Rev., 42, (2013), 9184–9195. DOI: 10.1039/C3CS60278H.
[4] M. Nybo and J.S. Madsen, Serious anaphylactic reactions due to protamine sulfate: a systematic literature review, Basic Clin. Pharmacol. Toxicol., 103, (2008), 192–196. https://doi.org/10.1111/j.1742-7843.2008.00274.x.
[5] S.Välimäki, N.K. Beyeh, V. Linko, R.H.A. Ras, M.A. Kostiainen, A supramolecular host–guest complex for heparin binding and sensing, Nanoscale, 10, (2018), 14022-14030. DOI: 10.1039/C8NR03132K