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  • articleNo Access

    BIOBOARD

      SINGAPORE – Singapore eHealth Innovations Summit Announces the First EMRAM Stage 7 Hospital in Singapore and Emphasized Technology as Transformative Agent in Specialty Functions.

      TAIWAN – Health2Sync Strategically Partners with Taiwan's Ministry of Health and Welfare in Asia's First Government Supported Online Diabetes Care Program.

      UNITED STATES – Scientists Identify Protein Involved in Restoring Effectiveness of Common Treatment for Breast Cancer.

      UNITED STATES – Scientists Reveal How Signals from Pathogenic Bacteria Reach Danger Sensors of Cells.

      UNITED STATES – Scientists Find New Path in Brain to Ease Depression.

      UNITED STATES – Tips for Living a Heart Healthy Lifestyle.

      CANADA – Review Suggests Eating Oats Can Lower Cholesterol as Measured by a Variety of Markers.

      SOUTH KOREA – CSA Group Opens Highly Advanced Electro - Medical Laboratory in Seoul.

      AUSTRALIA – Cynata’s Technology Significant Efficacy in Preclinical Asthma Study.

      INDIA – Essilor Launches ‘Love to See Change’ Campaign to Educate People about Need to Preserve Visual Health.

    • articleNo Access

      OZONE SENSING PROPERTIES OF THERMALLY EVAPORATED In2O3-BASED THIN FILMS

      Nano01 Aug 2008

      Ozone sensing properties of mixed oxides of In2O3, ZnO, and SnO2 in the form of thin films are explored. Exposure to ozone causes defects in the materials, and subsequently causes changes in the materials properties. In this work, a cost-effective, room temperature, real-time ozone monitoring device has been developed. The fabricated sensors are capable of detecting threshold ozone safety levels proposed by the World Health Organization (WHO) while operating at room temperature. Room temperature operation offers many advantages over high temperature operation, such as reduced power consumption, reduced fabrication costs, and ease of implementation into portable devices, such as laptops and mobile phones. The fabrication of these sensors was carried out by means of an Edwards E306A Coating System. Various mixtures of In2O3, ZnO, and snO2 were deposited in a rectangular pattern on top of copper interdigitated electrodes. X-ray Photo Spectroscopy (XPS) analysis showed that there were levels of impurities in the sensor samples, which were dependant on the fabrication process and parameters. XPS analysis also gave a detailed account of the shifts in binding energies of the thin oxide layers. The results presented show that the highest response to environmentally relevant ozone concentrations is achieved with a very thin sensing layer and a high deposition rate. The performance of the sensors has been investigated and compared.

    • articleNo Access

      TEM INVESTIGATIONS ON CNT-ADDED HEXAGONAL WO3 FILMS FOR SENSING APPLICATIONS

      Nano01 Aug 2008

      In this work, nanocrystalline hexagonal tungsten oxide was prepared by acidic precipitation from sodium tungstate solution. TEM studies of nanopowders showed that the average size of the hexagonal nanoparticles is 30–50 nm. Novel nanocomposites were prepared by embedding a low amount of gold-decorated carbon nanotubes into the hex-WO3 matrix. The addition of MWCNTs lowered the temperature range of sensitivity of hex-WO3 nanocomposites to NO2 hazardous gas. The sensitivity of hex-WO3 with Au-decorated MWCNTs to NO2 is at the temperature range between 25°C and 250°C.

    • articleNo Access

      ELECTROCHEMICAL Co3O4 NANOPOROUS THIN FILMS SENSOR FOR HYDROGEN PEROXIDE DETECTION

      Nano01 Jun 2014

      The nanoporous Co3O4 thin films were prepared on indium tin oxide (ITO) glasses by an electrodeposition method. The surface morphology and composition of the nanoporous Co3O4 films were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDS) and X-ray photoelectron spectroscopy (XPS). The results show that the as-deposited nanoporous Co3O4 film is constructed by many interconnected nanoflakes with thickness of about 40 nm. The cyclic voltammetry (CV) measurement indicates that the nanoporous Co3O4 films exhibit remarkable electrocatalytic activities for the hydrogen peroxide (H2O2) reduction which shows that it is a good candidate to be employed as electrode materials for electrochemical sensing of H2O2. Further analysis indicated that the detection sensitivity of the sensor was 1.357 mA mM-1 cm-2 and the detection limit was estimated to be about 0.2 mM.

    • articleNo Access

      Molybdenum Trioxide Dihydrate-Graphene Composite for Electrochemical Detection of Thiourea Molecule

      Nano01 Mar 2016

      A novel electrochemical sensing platform was constructed based on a facile self-assembly procedure synthetic laminar molybdenum trioxide dihydrate (MoO32H2O)-graphene composite. Field emission scanning electron microscopy (FESEM), X-ray spectroscopy, X-ray diffraction (XRD) and Raman spectroscopy were employed to characterize the morphology and composition of the MoO32H2O-graphene composite. As a model molecule, thiourea was utilized to investigate the electrochemical behaviors of the MoO32H2O-graphene composite modified glass carbon electrode. The results show that the composite modified electrode has higher electron transfer rate than that of graphene modified electrode and bare glass carbon electrode meanwhile the peak currents of it has a good linear relationship with thiourea concentrations in the range of 2.40×10319.3×103M (R=0.998) with detection limit of 4.99μM (S/N=3). This novel electrochemical sensor exhibits a higher absorption capacity (3.87×108mol/cm2), a good reproducibility (1.41% relative standard deviation (RSD)), excellent anti-interference and a high stability. These excellent electrochemical properties of the MoO32H2O-graphene composite are attributed to the loose and porous structure and the synergistic effects between graphene and MoO32H2O, which make this composite material hold great potential applications for electrochemical sensor.

    • articleNo Access

      Comparison of Fast Response and Recovery Pd Nanoparticles and Ni Thin Film Hydrogen Gas Sensors Based on Metal-Oxide-Semiconductor Structure

      Nano01 Aug 2017

      In this study, two hydrogen sensors with Pd/SiO2/Si and Ni/SiO2/Si structures have been fabricated. Palladium nanoparticles are synthesized and then deposited on the oxide surface using spin coating. Capacitance–voltage curves for the Pd/SiO2/Si sensor at room temperature and for the Ni/SiO2/Si sensor at 140C in pure nitrogen and 1% H2–N2 mixture are described. The time required for reaching 90% of the steady-state signal magnitude (t90%) for Pd/SiO2/Si capacitor was 1.4s and for Ni/SiO2/Si capacitor was 90 s. The time interval for recovery from 90% to 10% of steady-state signal magnitude (t10%) for Pd/SiO2/Si capacitor was 14s and for Ni/SiO2/Si capacitor was 40min. For the Pd/SiO2/Si capacitor, the response is 88% and for Ni/SiO2/Si capacitor the response is 29%. Comparison of Pd nanoparticles capacitive- and resistance-based sensors shows that the metal-oxide-semiconductor capacitive is faster and more sensitive than the resistance-based hydrogen gas sensors.

    • articleNo Access

      Polysulfide/Graphene Nanocomposite Film for Simultaneous Electrochemical Determination of Cadmium and Lead Ions

      Nano01 Aug 2018

      An integrative electroanalytical method was developed for detecting Cd2+ and Pb2+ ions in aqueous solutions. Polysulfide/graphene (RGO-S) nanocomposites were prepared and their performance as electrochemical sensors for Cd2+ and Pb2+ was evaluated. The RGO-S nanocomposite was carefully characterized by scanning electron microscopy with energy-dispersive X-ray spectrometry, transmission electron microscopy, and X-ray photoelectron spectroscopy. The as-prepared RGO-S was incorporated into a pyrolytic graphite electrode (RGO-S/PGE) and used for detecting trace amount of Cd2+ and Pb2+ by differential pulse anodic stripping voltammetry. Under optimal conditions, the stripping peak current of RGO-S/PGE varies linearly with heavy metal ion concentration in the ranges 2.0–300μg L1 for Cd2+ and 1.0–300μg L1 for Pb2+. The limits of detection for Cd2+ and Pb2+ were estimated to be about 0.67μg L1 and 0.17μg L1, respectively. The prepared electrochemical heavy-metal-detecting electrode provides good repeatability and reproducibility with high sensitivity, making it a suitable candidate for monitoring Cd2+ and Pb2+ concentrations in aqueous environmental samples.

    • articleNo Access

      Bacterium-Derived Carbon Dots as a Novel “Turn-On-On-Off-On” Sensor for Cr(VI) and 4-Nitrophenol Detection Based on Inner Filter Effect Mechanism

      Nano01 Jun 2020

      Phenolic compounds, especially 4-nitrophenol (4-NP), and chromium (VI) are highly toxic environmental pollutants. Thus, it is significantly important to establish a rapid and sensitive sensor for 4-NP and Cr(VI) monitoring in environment. In this paper, a novel approach has been adopted where E. coli-derived CDs (CDs-WT) prepared by one step hydrothermal method previously and sensitized by ampicillin (turn-on) were used as fluorescence nanoprobe (CDs-WT-Amp) for 4-NP and Cr(VI) determination based on the inner filter effect quenching mechanism (turn-off). Then, the quenching fluorescence was reversed by addition of ampicillin (turn-on). The linear ranges of 4-NP and Cr(VI) detection were 0–50μM and 0–25μM, with the limits of detection 88.89nM and 64.75nM, respectively. The “turn-on-on-off-on” fluorescent nanosensor system was successfully used to determine Cr(VI) and 4-NP in water with satisfactory results. It shows that the “turn-on-off-on” nanoprobe has great promising potential for application to environmental pollutant detection.

    • articleNo Access

      Multifunctional Encapsulating Gold Nanoparticles into Cu-Hemin/Metal-Organic Frameworks for Catechol Electrochemical Detection on Graphene-Based Electrode

      Nano25 Nov 2020

      A new type of multifunctional metal-organic frameworks (MOFs) was synthesized by encapsulating gold nanoparticles (AuNPs) into the Cu-hemin MOFs, and first applied to an electrochemical sensor to detect catechol (CT) with the aid of electrochemically reduced graphene oxide (ERGO) for signal amplification. First, ERGO was electrochemically deposited on a bare glass carbon electrode (GCE), followed by casting Cu-hemin MOFs on an ERGO-modified electrode, and then growing AuNPs in situ on Cu-hemin MOFs/ERGO/GCE by electrochemical deposition. Cyclic voltammetry (CV), scanning electron microscopy (SEM) and current–time (It) were utilized to characterize the electrochemical performance and surface characteristics of the as-prepared sensor. The results demonstrated that Cu-hemin MOFs have not only been a matrix to avoid the aggregation of AuNPs but also an ideal loading platform for the adsorption of CT due to its large surface area and porosity. In addition, the ERGO also has the advantage of fast electron transfer, which can make synergy with AuNPs@Cu-hemin MOFs nanocomposites to amplify the electrical signal. The AuNPs/Cu-hemin MOFs/ERGO/GCE exhibited an excellent electrocatalytic activity with increased electrochemical signals towards the oxidation of CT. Under the optimum experimental conditions, the sensor shows a wide linear relationship over the range of 2.0×106M to 1.692×103M with a detection limit of 2.0×107M. Moreover, the sensor presented the good reproducibility and the excellent anti-interference performance. This work would broaden the application of MOFs material in constructing more novel electrochemical sensing platform.

    • articleNo Access

      Preparation of Copper and Nickel-Based Oxide Self-Supporting Electrode by Electrochemical Etching Method for the Detection of Glucose

      Nano30 Jun 2021

      It is of great significance to prepare electrochemical glucose sensors with high selectivity and stability via effective and rapid methods. In this work, the self-support electrode with copper and nickel-based oxide is prepared by chemical-etching reaction which occurred under the property of electrochemical potential difference. In this processing, nickel foam is etched selectively by Cu2+ ions and they not only act as self-supporting electrode substrate, but also as nickel ions precursor of NiO. Moreover, the reaction can be completely satisfied on 30 min at room temperature. As a self-supporting electrode nonenzymic glucose electrochemical sensor, the electrode exhibited a wide linear range (0.04–3.00mM), low detection limit (0.02mM) with high sensitivity of 1096μAmM1cm2 and good selectivity, repeatability and stability. Furthermore, the application of the prepared sensor provides an avenue for the application of the transition metal materials in the field of electrochemical sensing.

    • articleNo Access

      MWCNTs and MoS2-Sensitized BiVO4 Photoanode for Improved Hydrogen Peroxide and Hypochlorite Sensing

      Nano01 May 2022

      Multi-walled carbon nanotube (MWCNT)-modified MoS2/BiVO4 was manufactured and used for the photoelectrochemical (PEC) detection of hydrogen peroxide (H2O2) and hypochlorite (ClO). A solvothermal method was used to synthesize an MWCNT/MoS2/BiVO4 composite that showed perfect PEC properties because the MWCNTs and MoS2/BiVO4 heterostructures increased the composite’s stability against photocorrosion. Compared with the same signal of MWCNT/MoS2/BiVO4, the photocurrent signal of other composites was much smaller upon irradiation by visible light. According to this PEC sensor, the linear range of the H2O2 concentration was 1–200μM and 280–1560μM at pH=7.4 based on the same pH when detecting ClO concentrations between 0.5–10μM and 20–340μM in a bleach sample. As a result, this sensor can be used to detect reactive oxygen species (ROS) in practical samples.

    • articleNo Access

      Reduced Graphene Oxide/MXene-Derived TiO2 Hybrid Interface Layer for the Improvement of Zinc Oxide Nanorod Growth and Their Applications in Glutathione Sensing

      Nano01 Jul 2022

      Photoelectrochemical (PEC) sensor is an important type of biosensor widely used in glutathione (GSH) sensing. The PEC properties of the photoanode present in the sensor are critical to its sensing performance. Zinc oxide (ZnO) is an excellent semiconductor with a suitable band gap and light absorption ability for photoanode applications. Meanwhile, the interfacial layer is also important in the separation and transportation process of the excitons. In this work, high-quality ZnO nanorods were grown on the indium tin oxide (ITO) substrates. An interfacial layer consisting of reduced graphene oxide (RGO) or MXene (a two-dimensional transition metal carbide)-derived TiO2 was introduced. Our results show that the introduction of the RGO/TiO2 hybrid interfacial layer can promote both the high-quality growth of ZnO nanorods and also provides suitable band gap grading for efficient excitons separation and transportation. The GSH sensing performance of the PEC sensor based on the ZnO nanorods grown on the RGO/TiO2 hybrid layer-coated ITO photoanode can dramatically improve the photocurrent strength and linearity.

    • articleNo Access

      SOFT SENSORS FOR MONITORING RESPIRATORY AND HEART SOUND

      The soft sensors for monitoring respiratory and heart sound were composed of polyurethane and microphones. In this study, silica was blended with polyurethane to change the hardness of the chambers. The hardness would influence the frequency response of the sensors. The material composed of 60 phr silica was chosen to make the chamber of the sensor. It had higher hardness and resulted in the flatten frequency response across the range of 100–1200 Hz. By the filter band designed for heart sound and respiratory sound signal, the heart sound and respiratory sound can be collected. The measured sound was verified by the physician and showed no distortion.

    • articleNo Access

      OPTICAL SENSING PROPERTIES OF WO3 NANOSTRUCTURED THIN FILMS ON SAPPHIRE SUBSTRATE TOWARD HYDROGEN

      Many studies have identified tungsten trioxide (WO3) as a promising candidate for optical gas sensing applications. WO3, coated with thin catalytic metals such as Pd, was reported to show a color change from transparent to dark blue upon exposure to oxidizing gas such as hydrogen (H2). Reliable hydrogen sensor is widely used in medical and energy application area. In this work, WO3 nanostructured thin films were deposited onto sapphire substrates via pulsed laser deposition (PLD) technique by using ArF Excimer laser operating at very short wavelength of 193 nm, the shortest wavelength used in the fabrication of semiconductor oxide thin films. By ablating the target oxides by high energy photons, we could fabricate good crystalline nanostructure thin films. Electron microscopy studies revealed that the uniform and homogeneous WO3 nanostructured films consist of nanorods of about 50 nm sizes. XRD and Raman studies verified good crystalline formation. Absorbance response toward H2 gas was investigated for a WO3 film coated with 25 Å thick palladium (Pd). The Pd/WO3 nanostructured thin films exhibited excellent gasochromic response toward H2 when measured in the visible-NIR range at 100°C. As low as 0.06% H2 concentration was clearly sensed. The larger dynamic response was measured at NIR wavelength of 900 nm as compared to the response at visible wavelength of 500 nm. The dynamic response of the films observed in the range of 500–800 nm showed more significant response toward H2 with low concentrations (0.06%–1%) than the one at single wavelength. As a result, H2 with very low concentration was able to be sensed reliably in real time. The response and recovery times were found to be < 2 min. The results indicated that the Pd/WO3 nanorod films on sapphire substrates responded to very low H2 concentration (0.06%) which is well below its lower explosive level threshold (4%).

    • chapterNo Access

      Application of Inherent Safety and TRIZ in the Innovation Design of Intelligent Pacifier

      This study proposed a novel design of intelligent pacifier, in order to help the caretakers knowing when to feed the newborn infants or premature infants who do not have sufficient sucking ability. By adopting the inherent safety and TRIZ methods, the inherent safety analysis and design could effective prevent the injuries caused by improper feeding. Furthermore, Su-Fields Analysis was performed to identify the problems, and 76 Standard Solutions were used to find the possible design structure for systematic innovative design. The intelligent pacifier was designed with a distortion sensor to detect the changes of sucking ability and frequency of the infants. The data were transmitted via the wireless transmitter to a remote receiver, and the computing module of the intelligent pacifier would display the actual sucking force and frequency on the screen. Then, the caretakers could refer to the data and provide proper care for the infants.