bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multimode Microsensors Based on Carbon Matrices for the Screening of Whole Blood for IL-6
Authors: Stefan-van Staden Raluca-Ioana , Gugoasa Livia A 
Published: February 2020

High levels of interleukin-6 are associated with prostate cancer, breast cancer, stress, lupus, cardiovascular diseases and obesity. A fast and simple method of screening for IL-6 is needed for early diagnosis of these conditions. Therefore, multimode sensors based on cabon matrices, such as graphite, graphene, fullerene C60, and multiwall carbon nanotubes modified with maltodextrin were designed for the assay of IL-6 in whole blood samples. The best limit of determination (10fg/mL) was recorded when the microsensor based on maltodextrin immobilized in C60 fullerenes was used for the assay of IL-6 in whole blood samples.
Acknowledgements The present work was supported by UEFISCDI, Romania PNII, Ideas (2011-2015), Contract-no. 123/2011.
(Keynote) Near-Zero-Power Electrochemical Sensors for Wearable Wireless Health, Safety, Surveillance and Environmental Electronics
Authors: Stetter Joseph R , Carter Michael T , Stetter Edward F 
Published: February 2020

An emerging GDP revolution based on fusion of computing, communication, and sensing will bring a state of “abundance” and create the largest bull market in history [1]. Technical global tides including the Internet of Things (IoT), Mobile/Wearable electronics, Digital Health, and context computing are driving the need for billions of sensors. Healthcare will require 50 or more sensors on the body and will shift emphasis in healthcare from diagnosis of disease to the business of wellness. Amazon has introduced a wearable electronics section validating this new market segment and acknowledging the rapid growth. The IoT with cloud and fog computing is planning to use trillions of sensors for “crowd” monitoring of our health, safety, security, and environment. The disruptive characteristic of the needed gas sensors always includes low power but the technology must also be low cost and scalable to high volumes in order to be successful in high volume applications. These restrictions also usually come with the need for high performance and small unobtrusive packaging.
Herein we report the smallest amperometric sensor we have made to date [5x5x1mm, below] and their performance. The amperometric sensor technology actually generates a small current [few nA] and, in some cases, can be galvanic and require no external power to operate. The sensors typically utilize a low power potentiostat [1.2 nA at 3 V] as well as sense the gases around and inside of us performing breath and environmental analysis. The gas sensors are combined with low-power or energy harvesting circuits for computing, reporting, and communication to provide situational awareness on mobile platforms and in our infrastructure. The new sensors are made using PE [printed electronics] technology that can be scaled to billions of units and are sensitive to breath gases [e.g., acetone, alcohol, CO] and environmental gases [CO, NO2, SO2, ozone] at ppb and ppm levels with rapid response, multi-year lifetime and often important selectivity. Consumer products are in the stores starting in the fall of 2014 using the newest SPEC sensors [2] and the technology is reported here.
1] T-Sensors Summit, November 11-13, 2014, San Diego, CA, www.Tsensors.org.
2] www.spec-sensors.com.

Figure 1
(Keynote) Oxygen Sensing Microfluidic Structures for Biomedical and Environmental Science Research
Authors: Grate Jay W , Kelly Ryan , Anheier Norm , Suter Jonathan , Schmidt Tom , Vasdekis Andreas 
Published: February 2020

Planar optode films consisting of a fluorescent dye in a polymer film can be incorporated into microfluidic structures to map out oxygen concentrations while microfluidic devices set up gradients and environmental conditions that are relevant to biomedical or natural biogeochemical systems. Gradients of molecular oxygen are of particular interest due to the fact that many important biological processes either occur at interfaces or are regulated by the flux of oxygen and other resources. Hence, oxygen sensing microfluidic devices can be used to investigate microbial behavior related to carbon cycling, or microbial communities in the gut where the interface with the host tissue is microoxic. In addition, oxygen sensing microfluidic devices may be useful in mammalian cell or tissue culture where favorable conditions must be maintained. Practical issues in developing and fabricating microfluidic structures with inherent oxygen sensing capability include multiple parameters, including incorporation of sensing elements in microfluidics, imaging oxygen concentrations by fluorescence, and relating oxygen imaging data to spatial structure of the microfluidic channels, all in useful structures that create biologically relevant microenvironments. We will describe multiple approaches to meeting these challenges, including gas impermeable silicon-on-glass structures where the fluorescent signals are only observed where microfluidic channels occur, and solvent imprinting lithography where sensing dyes can be incorporated in thermoplastics in a single process that enables sensor dye impregnation, channel imprinting, and cover plate bonding. These methods are discussed with regard to structures including pore network and gradient generation microfluidic structures.
Estimation of Crystalline Structure and Gas Transport Properties of Crystalline Fluorinated Copolymer
Authors: Matsuba Go , Nyuui Tatsuki , Sato Shuichi , Nagai Kazukiyo 
Published: February 2020

PFA has a unique role in the plastics industry due to its inertness, heat resistance, and low coefficient of friction in a wide temperature range. Generally speaking, fluorinated compounds and fluoropolymers have excellent chemical resistance, and oil- and water-shedding resistance. They have been used as rubbers at high temperatures and in several lubricating fluorine manufactured products.
Anyway, the crystalline polymers were used in the gas permselective, barrier and separating films. The gas transport properties are related to solubility, diffusivity and permeability in a polymer. In general, gas permeability, diffusivity, and solubility decrease with increasing crystallinity in a polymer film, because of gas molecules cannot diffuse and dissolve in the crystalline region. A few paper reported gas transport properties of PFA. In these papers discussed film thickness, pressure and grade dependence of gas permeability in PFA. However, there has been no systematic research on the relationship between gas transport properties and crystalline structure in PFA.
We have investigated the relationship between amorphous structure and its gas permeability of Poly(tetrafluoroethylene-co-perfluoroethylvinylether) (PFA) films using differential scanning calorimetry (DSC), wide-angle, small-angle X-ray scattering and quasi-elastic neutron scattering measurements. We focused on the hierarchical inter-lamellar amorphous structure of various gas-permeable PLA films. For controling cooling rate from the molten state, we prepared various crystallinity sample. The crystallnity range is between 29.3% (melt quenched) and 38.3 % (cooling rate, 0.5 K/min).
From wide-angle x-ray scattering measurements, the crystal lattice is independent of cooling rate, however, the lamellar crystal structure is strongly dependence on the cooling rate. The thickness of lamellar crystal and amorphous increase with decreasing cooling rate. The gas permeability coefficient was almost independent of crystallinity, that is, below crystallinity of 32 %, the gas permeability and diffusivity decreases with increasing crystallinity, while above that of 32%, it is independent of crystallinity. The order of gas permeability coefficient of all PFA films was the same as that of gas size such as the kinetic diameter: 2.89 Å (H2), 3.30 Å (CO2), 3.46 Å (O2), 3.64 Å (N2), 3.80 Å (CH4). The gas molecules might pass through the amorphous region of inter-lamellar crystals. Furthermore, we evaluated the relaxation processes of various crystallnity PFA films with quasi-elastic neutron scattering measurements. The films has two relaxation mode, 10^-12 s and 10^-13 s. The longer relaxation time component (~10^-12 s), which was assigned as "relaxation of side chain", has correlated with gas permeability.
Antibody-Free Electrochemical Detection of Cortisol Using Molecularly Imprinted Polymer
Authors: Manickam Pandiaraj , Pasha Syed Khalid , Bhansali Shekhar 
Published: February 2020

Cortisol, an important steroid hormone in the body plays a key role in several stress related diseases including post-traumatic stress disorder [1-2]. Its continuous detection at room temperature still remains a challenge for providing timely health care to patients suffering from such diseases. We report here a novel, highly sensitive, and selective electrochemical cortisol sensor using molecularly imprinted polymer (MIP). MIP are synthetic polymers having highly specific recognition sites selective towards the target analyte and considered to be the versatile, stable and cost-effective alternatives for the natural antibodies. The cortisol specific MIP film was prepared by in situ electropolymerization of pyrrole [3] monomer onto the electrode surface in the presence of cortisol as a template. After removing the cortisol by electrochemical over-oxidation, the specific imprinted sites created on the polymer matrix were used to detect cortisol using ferrocyanide/ferricyanide (K3[Fe(CN)6]/K4[Fe(CN)6]) as a redox mediator. The imprinted sites on the electrode were characterized by cyclic voltammetry and scanning electron microscopy. The effect of experimental variables on the current response such as, electro-polymerization cycles, template/monomer ratio, elution condition for target removal, pH of the supporting electrolyte, and rebinding time were also investigated and optimized. The MIP based cortisol sensor exhibited a good detection limit of 1 pM mL-1cortisol. Moreover, the sensor showed a good reusability, i.e., the sensitivity remained >90% after 6 cycles of elution/rebinding, while the sensitivity only decreased to 90% after 4 weeks of storage at room temperature. Simplicity in preparation, high affinity towards cortisol, and stability superior to antibodies makes the MIP technology, a potential candidate for commercializing the cortisol sensor for point-of-care diagnosis.

References:

[1] Rachel Yehuda, Sarah L Halligan, Robert Grossman, Childhood trauma and risk for PTSD: Relationship to intergenerational effects of trauma, parental PTSD, and cortisol excretion. Development and Psychopathology 13 (2001) 733–753.
[2] Syed Khalid Pasha, Ajeet Kaushik, Abhay Vasudev, Shedra Amy Snipes, Shekhar Bhansali, Electrochemical Immunosensing of Saliva Cortisol, Journal of Electrochemial Society 161 (2014) B3077–B3032.
[3] Manickam Pandiaraj, Niroj Kumar Sethy, Kalpana Bhargava, Vepa Kameswararao, Chandran Karunakaran, Designing label-free electrochemical immunosensors for cytochrome c using nanocomposites functionalized screen printed electrodes, Biosensors and Bioelectronics 54 (2014) 115–121.
Pattern Recognition of HER-2 in Whole Blood Samples Using Stochastic Sensors
Authors: Moldoveanu Iuliana , Stefan-van Staden Raluca-Ioana 
Published: February 2020

Chitosan and maltodextrin based diamond paste sensors were design, and characterized for the assay of HER-2 a biomarker for breast cancer.
The “signatures” of HER-2 were recorded for each stochastic sensor, and further used to identify these analytes on the patterns obtained when whole blood was screened. Quantitative analysis was also performed using these sensors. The results obtained using the proposed sensors were correlating very well with those obtained using the standard methods used in clinical analysis (e.g., ELISA).
Acknowledgements This work was supported by UEFISCDI PNII Program Ideas 2011-2014, Contract nr. 123/05.10.2011 and by ERC-like-3/07.2012 program.
(Invited) A Chemiresistive Glucose Sensor Based on Polyaniline Nanowire Network
Authors: Song Edward , Choi Jin-Woo 
Published: February 2020

A simple fabrication technique of a low cost and disposable glucose sensor is proposed and demonstrated. The sensor consists of an inkjet-printed polyaniline nanowire network pattern as a chemiresistive sensing material and glucose oxidase with metallic nanoparticles as enzyme and catalyst for detecting glucose.
In this work, we propose the use of catalytic nanoparticles and glucose oxidase (GOx) in conjunction with polyaniline nanowires for the development of a printable glucose sensor that is simple, low cost and manufacturable on a large scale. The working principle is as follows: glucose oxidase converts glucose into to gluconolactone and in the process releases hydrogen peroxide as a byproduct. Hydrogen peroxide reacts with the catalytic nanoparticles to produce hydroxide ion resulting in an increase in pH. Since the conductivity of polyaniline is pH sensitive, any production of hydrogen peroxide will lead to an increase in resistance of the polyaniline. Hence the concentration of glucose can be determined by observing the change in the conduction current through the polyaniline-based chemiresistor.
Polyaniline nanowires were chemically synthesized and printed on a PET film by inkjet printing. Subsequently, catalytic nanoparticles and glucose oxidase were deposited and dried on the patterned polyaniline nanowires. The printed sensor was tested with glucose and the conduction current change was observed. The concept demonstrated in this work can potentially lead to a fully printed biosensor.

Figure 1
Graphene Based Materials for Arsenic Sensing and Removal from Contaminated Water
Authors: Assirelli Alessandra , Ieffa Simona , Bernasconi Roberto , Nobili Luca , Magagnin Luca 
Published: February 2020

Environmental pollution especially toxic gases, heavy metal ions and organic pollutants in air and water, caused by industry and agricultural activities, severely threaten ecological balance and human health, and have received extensive attention worldwide. Arsenic contamination of groundwater is a critical problem that aﬀects millions of people across the world and results in severe diseases such as skin or lung cancer and bladder cancer. Widespread arsenic contamination of groundwater has led to a massive epidemic of arsenic poisoning in Asia and America, especially such as India, Bangladesh, Vietnam, Cambodia, Thailand, southwest USA, Canada, Chile, and neighboring countries.
Graphene has become a promising material for many different applications, such as nanoelectronic devices, physical, chemical and biochemical sensors, transparent conductive films, clean energy devices, or nanocomposite formulation. Sensing applications using graphene sheets as transducers have experienced a surge in the last few years, especially for gas sensing platforms, or electrochemical sensors, because of the high electrical conductivity of graphene.
In this work, we investigate the synthesis of graphene by methane decomposition at 1000 °C onto free standing electrodeposited substrates, studying the effects of the electrochemical synthesis onto graphene quality. The growth of good quality graphene layers is also discussed in terms of the role played by grain boundaries and diffusion at the grain boundaries. As an advance of graphene studies, 2D graphene nanomaterials have been applied to arsenic sensing and removal from contaminated water. The work will discuss our latest studies and progresses on the application of graphene-based materials in the environmental protection and detection for arsenic contaminated waters. The work will present the use of graphene based electrodes for electrochemical sensing of arsenic; a similar approach will be discuss for arsenic removal, discussing kinetics and performances of the process.
The Effect of Distribution of Uvlight on Elastic Modulus of UV Cured Film in Roll-to-Roll Nanoimprint Process
Authors: Kondo Shunsuke , Taki Kentaro , Ito Hiroshi 
Published: February 2020

The Roll-to-Roll UV nanoimprint process (R2RUVNIP) is a promising technology to fabricate nanostructure on flexible films. In nanoimprint process, there is an issue how to find a feasible operating condition to peel-off the UV resin from the mold. To produce a desired nanostructure by the R2RUVNIP, the conversion and surface elasticity of UV-cured resin in
the process are needed to be known precisely to optimize the UV intensity and line speed. In this study, a UV curable resin (1,6-bis(acryloyloxy)hexane) was cured in the roll-to-roll nanoimprint process. Then the conversion and surface elastic modulus of UV resin were measured with FT-IR and nano indenter, respectively. The effect of distribution of UV light on the roller mold was investigated. The sharp distribution of UV light was effective to increase surface elastic modulus at a given conversion of monomer.
Effects of Pt-Based Electrode Compositions on CO Sensing Properties of NASICON-Based Solid Electrolyte Gas Sensors
Authors: Shimizu Yasuhiro , Takeda Hirotaka , Ueda Taro , Kamada Kai , Hyodo Takeo 
Published: February 2020

We have reported recently the potential of planar-type NASICON-based solid electrolyte gas sensors equipped with Pt mixed with Bi2O3as a sensing electrode and pristine Pt as a reference electrode [1]. This type of sensors could be operated at room temperature with sufficiently high CO response and selectivity. The present study was directed to investigating the effects of the addition of various kinds of metal oxides to both the Pt sensing and reference electrodes on the CO sensing properties.
Pt paste (Tanaka Corp., TR-7907) mixed with an appropriate amount (n wt%) of a metal oxide (MO), which is denoted as Pt(nMO), and just Pt paste or another kind of Pt(nM’O) were applied on the same surface of the NASICON disc as a sensing and a counter electrode, respectively, and then were fired at 700ºC for 30 min in air. The sensor thus fabricated was denoted as Pt(nMO)/Pt or Pt(nMO)/Pt(nM’O). The metal oxides tested were Bi2O3, La2O3, In2O3, V2O5, WO3 and CeO2. The magnitude of gas response was defined as the difference in EMF (ΔEMF) measured between in a sample gas and in base air.
CO response properties of the sensors equipped with the pristine Pt reference electrode were found to depend on the kind of metal oxides added to the Pt sensing electrode. CO response with a EMF change to a positive direction was observed with a Pt(15Bi2O3)/Pt sensor, whereas a Pt(15CeO2)/Pt sensor showed a EMF change to a negative direction, as shown in Fig. 1. The operating temperature dependence of the CO response of sensors was also affected by the kind of the metal oxides added (see Fig. 2). By referring such CO response properties of these Pt(15MO)/Pt sensors, a Pt(15Bi2O3)/Pt(15CeO2) sensor was fabricated and then its CO response properties were further investigated in detail. The CO sensing performance of the Pt(15Bi2O3)/Pt(15CeO2) sensor in both dry and wet air atmosphere, including interferences from 300 ppm CO2, CH4, C3H6 and H2, will be reported in the presentation.
Reference
[1] H. Takeda, T. Ueda, T. Hyodo, Y. Shimizu, Abstract of the 10th Asian Conference on Chemical Sensors, Chiang Mai, Thailand, Nov. 11-14, p. 110 (2013).

Figure 1
(Invited) Ionic Liquids and Gas Sensor Applications
Authors: Zeng Xiangqun 
Published: February 2020

This presentation will discuss the notable contributions to the sensor fields using ionic liquids from our laboratory. Ionic liquids (ILs) are excellent solvents that have wide varying gas solubility for common gases and volatile organic molecules which have been demonstrated for the storage and delivery of gases that are flammable, and/or reactive. Ionic liquids also have good ionic conductivity and have been explored as nonvolatile and nonflammable electrolytes for many electrochemical device developments. In the past ten years, our laboratory has systematically investigated the redox mechanisms of common gases (i.e. CH4, NO2, SO2, H2, CO, CO2, O2) and small organic molecules (methanol, ethanol, formaldehyde, formic acid etc.) in ILs and we have identified new reaction mechanisms for ionic liquid based gas sensor development which uniquely overcome many sensor performance challenges, especially those related to sensing capability and miniaturized sensor system implementation. By synergistically utilizing the unique ionic liquid interface electrochemistry as well as molecular design and control of ionic liquid/conductive polymer composites, we have demonstrated new ionic liquid gas sensors enabling multiple gas detections with multiple modes detection principles via low cost and low power piezoelectric/QCM and electrochemical transducers that yields forward-thinking solutions to many gas sensors challenges, especially miniaturization and robustness. The simplicity of the demonstrated detection principles allows for easy integration with engineering advancements such as portable electronics, networked sensing and next-generation monolithic implementation of autonomous sensors with the performance, cost, power, and operational lifetime characteristics to suit a broad range of applications.
Polypyrrole-Coated Carbon Nanotubes for Low Temperature Gas Sensor
Authors: Kim Anna , Lim Hana , Lee Ho-Nyun , Jae-Young Park , Yoo Bongyoung , Kim Hyun-Jong 
Published: February 2020

Simple, low cost and energy efficient gas sensors for toxic gas measurements are in great demand for applications in industries and for environmental analysis. And, almost half a century ago, it has been already realized that semiconducting metal oxides have great potential as gas sensing materials, owing to the fact that chemical interaction of gas molecules with the semiconductor’s surface leads to changes in the electrical conductivity. Especially, SnO2 has been the most frequently used n-type semiconducting material for gas sensing. However, most of those inorganic sensors inherently suffer from some problems such as low selectivity, reduced life time, and relatively high operable temperature leading to increased power consumption which limit their versatility.
Recently, the conducting polymers have shown great promise in sensory applications. Delocalized electronic states combined with the restriction on the extent of delocalization leads to the formation of a large energy gap making most conductive polymers behave like p-type semiconductors. Advantages of using conducting polymers as sensing materials are ease of synthesis, fast response, low cost, and room temperature response.
In this study, polypyrrole-coated carbon nanotube(CNT) was prepared by chemical oxidation polymerization of pyrrole on the surface-functionalized carbon nanotube in the presence of FeCl3. As increasing the concentration of pyrrole, the thickness of polypyrrole layer on the surface of CNT was gradually increased. The obtained material was mixed with a solution containing gold(Au), platinum(Pt), silver(Ag) ion and simultaneously reduced by adding NaBH4 solution. The detection of carbon monoxide, toluene, and formaldehyde was systematically examined. Based on the gas sensing results, the thickness of polypyrrole, operating temperature, and concentration of metal catalyst were roughly optimized. Finally, the polypyrrole-coated CNT showed considerably promising gas sensing characteristics as compared to conventional SnO2 powder.