bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integration of Nanostructured Dielectrophoretic Device and Surface-Enhanced Raman Probe for Highly Sensitive and Rapid Pathogen Detection
Authors: Madiyar Foram , Bhana Saheel , Swisher Luxi , Huang Xiaohua , Culbertson Christopher , Li Jun 
Published: February 2020

Rapid and highly sensitive is critical for food safety and environmental protection. To achieve this, it requires the combination of both novel sample handling techniques and extremely sensitive detection methods. In previous studies, we have demonstrated the effective capture and quick concentration of pathogenic particles such as viral and bacterial particles in a fluidic chip using dielectrophoresis (DEP) enhanced with the highly focused electric field at the tip of an embedded nanoelectrode array. This work reports a further development with a synergistic approach to the concentration, detection and kinetic monitoring of pathogens through the integration of the nanostructured DEP device with nanotag-labelled Surface Enhanced Raman Scattering (SERS) for specific bacterial identification. A nanoelectrode array made of embedded Vertically Aligned Carbon Nanofibers (VACNFs) at the bottom of a microfluidic chip is used to effectively capture and concentrate nanotag-labelled E. coli DHα5 cells into a 200 micron x 200 micron area at which the Raman laser probe is focused. The SERS nanotags are based on iron oxide-gold (IO-Au) core-shell nanoovals (NOVs) of ~50 nm in size, which are coated with QSY21 Raman reporters and attached to E. coli cells through specific antibodies. The combination of the greatly enhanced Raman signal by the SERS nanotags and the effective DEP concentration significantly improves the detection limit and speed. The SERS signal has been measured with both a confocal Raman microscope and a portable Raman probe during DEP capture, and has been fully validated with fluorescence microscopy measurements under all DEP conditions. The SERS measurements are sensitive enough to detect a single bacterium. A concentration detection limit as low as 210 cfu/mL using a portable Raman system has been obtained with a DEP capture time of only ~50 s. The detection has been validated in purified solutions as well as complex samples including chicken broth, soil solution and apple juice. These results demonstrate the potential to develop a compact portable system for rapid and highly sensitive detection of specific pathogens. Furthermore, the AC impedance can be used to monitor the pathogen capture with slightly higher detection limit. Such system is reusable, requires minimum sample preparation, and is ideal for field applications.
Electrochemical Sensors to Detect Heavy Metals and Carcinogenic Compounds: Inquiry-Based Modules to Meet Today's Interest
Authors: Lunsford Suzanne Kay , Spradlin Corrie , Sullivan Mary , Dobson Dolores , Hughes Miyong 
Published: February 2020

The developments of novel electrochemical sensors to detect phenol (phenol derivatives) and heavy metals in solution have been a focus of our inquiry-based laboratory experiences. Our students are engaged into the applications of Controlled Potential Electrolysis (CPE) to create a modified working electrode to detect the common contaminants such as phenols and heavy metals in solutions by electroanalytical techniques such as cyclic voltammetry (CV), differential pulse voltammetry (DPV), and square wave anodic stripping voltammetry (SWASV). Additional analytical instrumentation skills were required through out these inquiry-based learning experiences to confirm the modified working electrodes (TiO2/ZrO2, Polymers and Carbon Nanotube, CNT) were electrochemically created by such instrumentation such as Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy and X-Ray Fluorescence. The students content gains were assessed through out these lab modules according to the R.R. Hake’ method. These content gains assessed will be discussed as well to exemplify the inquiry-based learning experiences of our undergraduate students experiences to meet the needs of todays workforce.
Sensor Research and Detection Technology for Efficient Water Usage and Security in Agriculture
Authors: KIM Dong-Joo 
Published: February 2020

Agriculture is the world’s largest consumer of water. Currently, 70% of global freshwater consumption is for agriculture, corresponding to a volume of over 2,500 km3. Unfortunately, water usage in agriculture is often highly inefficient with only a fraction of the water effectively used in plant growth. The rest of the water is lost via soil drainage, evaporation or transpiration. By 2050, the world’s population is expected to exceed 7 billion. The United Nations estimates that total agricultural water consumption will increase by 19% to meet global food demand. Additionally, increasing demand to shift more of the water used in agriculture to higher-value urban and industrial purposes will place additional stress on water for agriculture. Irrigation is also energy intensive. For example, irrigation with groundwater can lead to energy costs in the range of $10 to 100/acre per year. In California alone, agricultural irrigation uses 10 billion kilowatt hours of electricity annually.
Water use efficiency in agriculture has been researched extensively. Conversion from traditional furrow irrigation to micro-irrigation methods has been shown to reduce irrigation needs by about 50% while improving yields. Unfortunately, present practice is less than ideal and often fails to collect all information necessary for cost effective management decisions. The utilization of above-ground irrigation systems has been shown to be effective, but a lack of adequate sensors for monitoring and control has led to non-optimal irrigation practices. Improving the efficient use of water resources still demands the development of new technologies that cost less and save energy by accurately assessing crop status for a given location, climate and soil conditions.
Recently, advances in sensing and detection technologies as well as new approaches and protocols demonstrated potential for efficient irrigation control. Examples of the sensors include measurement of water efficiency, crop and soil-water conditions and evaluate food safety. Wireless sensor networks to transmit the measured information is also one of important technologies. As efforts to address issues in agricultural monitoring, our research team has developed smart dipstick sensors to measure liquid conditions including surface tension, viscosity, temperature, water content and acidity. Smart trap to monitor invasive pests and environment has demonstrated the use of sensor systems for protecting crops. A remote, wireless magnetoelastic biosensor has also been focused on identifying the presence of various pathogens for enhancing food safety and security.
Sensor system and detection technology will enable targeted applications of water, fertilizer and pesticides to greatly reduce costs, improve producer profitability, and lead to a more sustainable agriculture. Efficient irrigation will also reduce environmental degradation while lowering energy usage in agriculture.
Phase-Based Electrochemical Biosensors for Detection of Pathogenic Bacteria
Authors: Zhou Yan , Ramasamy Ramaraja P. 
Published: February 2020

Bacterial pathogens are universally present in the environment and easily contaminate food and water to cause serious food-borne illness to humans. Detecting these pathogens in ultra low quantities is critical to prevent major outbreaks of food-borne diseases. Several approaches have been explored for detecting pathogenic bacteria in food and water of which electrochemical biosensors offer unique advantages including rapid detection, high sensitivity and easy-to-use testing procedure. However the specificity of detection and the cost of the biosensor heavily depend on the type and nature of the bio-recognition element used. Enzymes and antibodies are highly susceptible to environment and have low stability when used on electrodes. In this work, bacteriophage (virus) has been explored as an alternative bio-recognition element for the detection of pathogenic bacteria. More specifically, a wild type T2 phage was utilized as recognition element for direct detection of Escherichia coli, ATCC 11303. The T2 phage was immobilized on carbon nanotube modified screen-printed carbon electrodes (SPE) using a molecular tethering approach developed by us.1 The binding of phage to the carbon nanotubes was verified by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The phage-modified electrodes were used to specifically detect E. coli. Electrochemical impedance spectroscopy was used to detect the impedance variations resulting from the binding of E. coli to T2 phage. The phage-based biosensor showed high sensitivity towards the detection of E. coli and the controls in the absence of phage did not show any signal for the E. coli detection.

References:

Ramasamy, R. P.; Luckarift, H. R.; ivnitski, D. M.; Atanassov, P. B.; Johnson, G. R., High electrocatalytic activity of tethered multicopper oxidase-carbon nanotube conjugates. Chemical Communications
2010, 46 (33), 5977-6188.

Figure 1
Detection of Multiple Pathogens on Fresh Produce Using a Surface-Scanning Coil
Authors: Wang Fengen , Horikawa Shin , Chai Yating , Hu Jiajia , Du Songtao , Liu Yuzhe , Wikle Howard Clyde , Chin Bryan A. 
Published: February 2020

The wireless phage-based magnetoelastic (ME) biosensor combined with a surface-scanning coil is being developed as a direct pathogen detection method on food surfaces. The biosensor consists of a free-standing ME resonator as the signal transducer that is coated with a genetically engineered phage as the biomolecular-recognition element. Due to the Joule magnetostriction effect, the biosensor can be placed into mechanical resonance when subjected to a time-varying magnetic field alternating at the right frequency. The detection is based on measuring a change in the sensor’s resonant frequency, which is proportional to the number of pathogens bound to the biosensor. This paper investigates the real-time detection of multiple bacterial pathogens, Salmonella Typhimurium and Bacillus anthracis Sterne spores, on apple surfaces using ME biosensors. Measurement biosensors coated respectively with E2 phage (specific for S. Typhimurium) and JRB7 phage (specific for B. anthracis Sterne spores) were prepared and used for detection. Control biosensors (without phage) were also fabricated and used to compensate the effects of environmental changes. Fresh apple surfaces were spiked with S. Typhimurium cells, B. anthracis spores and their mixtures with known concentrations. Both measurement and control sensors were placed directly on the apple surfaces, and these pathogens were detected simultaneously by wirelessly monitoring changes in the biosensors’ resonant frequency in real time in a humid environment. These frequency shifts were measured with a surface-scanning coil detector. The pathogen binding was then confirmed by optical and scanning electron microscopy. The results showed that specific binding of the pathogens on the measurement sensors has occurred. The effects of masking bacteria such as Escherichia coli on the detection performance were also investigated.
A New Nasicon-Structure Phosphor As a Blue Component for White LED
Authors: Kim Yoon Hwa , Im Won Bin 
Published: February 2020

White light-emitting diodes (WLEDs) continue to gain scientific and commercial important in the present age of solid-state lighting. High power WLED components are required strong thermal stability because its generate heat during LED operation. Thus, the eventual performance of the WLEDs based on phosphors strongly depends on the luminescence properties of the phosphors. Therefore, it is highly desirable to find new phosphors with high efficiency and thermal stability.
In this study, we report a new blue-emitting phosphor, the Eu2+-doped NASICON, which can be used to forbid thermal quenching of optical characteristic for WLEDs. The influence of isomorphic displacements on phase transition temperature and the change of photoluminescence intensity have been explored, and established their correlation. By fabricating of WLEDs, we explored for its potential suitability in WLED applications. This suggests that the phosphor displays great potential application as near-ultraviolet LEDs for white light generation, with high quality.

Figure 1
Single Particle Measurement Technique Using Tweezers-Type Probe for Insertion Materials
Authors: Yamada Yuto , Ohmura Tomohiro , Munakata Hirokazu , Kanamura Kiyoshi 
Published: February 2020

To evaluate the electrochemical properties of active materials of lithium-ion batteries, those composite electrodes including binder and conductive carbon are generally prepared and tested as coin-type and pouch-type cells. However, the use of composite electrode sometimes makes it difficult to investigate the intrinsic electrochemical properties of active material because the electrochemical response of composite electrode is strongly influenced by its porosity, thickness and composition. In order to eliminate such secondary factors from the electrochemical evaluation of active material, we have focused on single particle measurement, in which a single particle of active material can be measured [1]. So far, we have used a needle-type probe (current corrector) to measure the electrochemical properties of various single particles such as LiFePO4
[2] and graphite [3]. However, the needle-type probe is sometimes difficult to apply to the active materials with large volume changes during charge and discharge. In order to solve this problem, we have developed a tweezers-type probe (Fig. 1). In this study, this tweezers-type probe was applied to evaluate the intrinsic electrochemical properties of Si-based anode materials with large volume changes.
In single particle measurement, an optical microscope was set in a globe box filled with dry Ar gas, and a measurement cell was set on this stage. A single particle of target active material was pinched with a tweezers-type probe under microscope observation, and then its electrochemical measurement was carried out. A mixed solvent of ethylene carbonate (EC) and propylene carbonate (PC) (1:1 in volume) containing 1 mol dm-3 LiPF6 was used as an electrolyte solution.
Fig. 2 shows charge-discharge curves of a Si particle measured by using a tweezers-type probe. Typical charge and discharge curves of Si with potential plateaus at around 0.2 V and 0.4 V were observed [4]. When using a needle probe, it was difficult to maintain the contact with Si particle, resulting in poor reproducibility. In contrast, even repeating cycles, the contact between the tweezers-type probe and Si particle could be maintained by using the tweezers-type probe. This result clearly shows the advantage of tweezers-type probe on evaluation of intrinsic electrochemical properties of advanced active materials with large volume changes.
Reference
[1] Kaoru Dokko, Natsuko Nakata, Kiyoshi Kanamura, Journal of Power Sources 189 (2009) 783-785.
[2] Hirokazu Munakata, Bunpei Takemura, Takamitsu Saito, Kiyoshi Kanamura,
Journal of Power Sources 217 (2012) 444 – 448.
[3] Kaoru Dokko, Natsuko Nakata, Yushi Suzuki, Kiyoshi Kanamura, J. Phys. Chem. C 114 (2010) 8646-8650.
[4] S. D. Beattie, D. Larcher, M. Morcrette, B. Simon and J.-M. Tarascon, J. Electrochem. Soc. 115 (2008) A158-A163.

Figure 1
Improvement of Electrode/ Electrolyte Interfaces in Graphite/LiNi0.5Mn1.5O4 Batteries at High Voltage with Lithium Trimethyl Alkyl Borates As Electrolyte Additives
Authors: Lucht Brett L , Xu Mengqing , Zhou Liu , Dong Yingnan , Totempudi Usha , Garsuch Arnd , Chesneau Frederick Francois 
Published: February 2020

Lithium trimethyl alkyl and aryl borates (LTMB) has been prepared and investigated as a novel cathode film forming additive to improve the performance of LiNi0.5Mn1.5O4 cathodes cycled to high potential (4.8 V). Addition of LTMB to 1.2 M LiPF6 in EC/EMC (3/7) improves the capacity retention of graphite/LiNi0.5Mn1.5O4 cells cycled at 55 oC. The added LTMB is sacrificially oxidized on the surface of the cathode during the first charging cycle. The LTMBs can be used as a functional group delivery agent via reaction of trimethyl borate with of the appropriate lithium alkoxide. Over 40 different LTMBs have been prepared and investigated. Ex-situ surface analysis of the LiNi0.5Mn1.5O4 by Attenuated Total Reflectance Infrared Spectroscopy (ATR-IR), Transmission Electron Microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) reveals inhibition of electrolyte oxidation on the cathode surface and the presence of a borate based passivating layer. The novel cathode electrolyte interface (CEI) leads to the performance improvements.
(Invited) Study of SEI on High Performance 3D SiNWs and Sinps Based Anode for Lithium Ion Batteries
Authors: Peled Emanuel , Patolski Fernando , Golodnitsky Diana , Freedman Kathrin , Davidi Guy , Schneier Dan , Goor Meital , Goldstein Keren 
Published: February 2020

In order to increase the energy density of the lithium battery, better anodes and cathodes are still required. Silicon has attracted much attention because its theoretical capacity is 4200mAhg−1, an order of magnitude greater than that of graphite. Nevertheless, the main disadvantage of high-capacity anode materials is their very large volume expansion and contraction (~320% ) during Li insertion/de-insertion, followed by cracking and pulverization of the anode material. Si nanostructures have the advantage of a shorter diffusion distance for lithium species, which can improve the power performance of the battery. Studying of large surface capacity anodes (high Si loading) is almost nonexistent. Several degradation mechanisms are involved in the charge-discharge process of SiNWs-based anodes, including: 1) SEI thickness and resistance increase, 2) solvent and salt reduction which leads to drying out of the electrolyte and to precipitation of a "secondary" porous SEI, 3) large increase in battery impedance and reduced power, 4) breaking or disintegration of the SiNWs, 5) loss of SiNW contact to the current collector and 6) cracks in the electrode due to large volume expansion of the SiNWs. In this work, in addition to the synthesis and characterization of novel three-dimensional high-capacity SiNWs and SiNPs-based anodes, we focused on studying their degradation mechanisms. We have been able to produce remarkably high loadings of 3-15 mAh/cm2, very low irreversible capacity (of the order of only 10% for the 3-4 mAh/cm2 samples), current efficiency greater than 99.5% and a fast charge–discharge rate (up to 2.7C (20mA/cm2) which is not common for silicon anodes). These properties meet the requirements of lithium batteries for portable and electric-vehicle applications. These SiNWs-based binder free anodes and the SiNPs anodes have been cycled for over 200 cycles, exhibiting a stable cycle life. Loss of capacity, at 0.1 mA/cm2, is about 20% only indicating that at least 80% of the SiNWs and the SiNPs are still connected to the substrate. It was found that both the SEI and the diffusion impedance grow with cycling. The thickness of a freshly formed SEI on lithium or on other substrates such as nickel, copper, stainless steel and carbon is a few nanometers only (the tunneling range of electrons (Peled 1979). During open circuit voltage conditions, and further exacerbated on cycling, the thickness and the resistance of the SEI grow with time. It was found that all measured parameters for the 3D SiNWs anode: Rsei, ρsei and SEI thickness grow with cycle number. For example: the SEI thickness after one and eleven cycles is 22 and 72 nm respectively and SEI resistance, of lithiated SiNWs anodes, grows from 17.8 (first cycle) to over 109 ohms.cm2 (after 71 cycles). The structure and composition changes of the SiNWs, the SiNPs and of the SEI will be reported.
Cyclic Carbonate Additives Effect on the Solid Electrolyte Interphase of Li Ion Batteries
Authors: Tavassol Hadi , Esbenshade Jennifer , Gewirth Andrew A. 
Published: February 2020

We report on the effect of vinylene carbonate (VC) and vinyl ethylene carbonate (VEC) electrolyte additives on the formation, stability and Li+ transport properties of solid electrolyte interphase (SEI). The SEI is thought to consist of an inner inorganic part with an outer organic layer, likely formed via oligomerization of the solvent, which may change in the presence of additives.
Our analysis of a Au model anode system in a 1 M LiClO4/propylene carbonate electrolyte solution with and without additive molecules shows that additives influence the lithiation current, as well as the mass and rigidity of the SEI film. Addition of the additive molecules increases the lithiation current. VC-containing solutions exhibit the highest lithiation currents. Interestingly, when comparing the additive containing electrolytes, increasing the concentration of additives causes an over-potential for the lithiation, which results in lower lithiation currents. These preventive effects are more pronounced in VEC containing electrolytes. Our results suggest that addition of additive molecules, influences the performance of Li ion batteries in part by modifying the SEI rigidity. Addition of VC decreases film rigidity, while providing a stable protective layer, which improves stability of the SEI film.
Structural Analysis for Lithium Ion Conduction in Li-P-S Solid Electrolyte
Authors: Mitsui Akio , Ohara Koji , Mori Masahiro , Onodera Yohei , Koyama Yukinori , Arai Hajime , Uchimoto Yoshiharu , Ogumi Zempachi 
Published: February 2020

Introduction and Result

Batteries are used to power electric and hybrid electric vehicles, and to store a wind and solar energy in smart grids. The research and development of electrical vehicles has been an important subject. All solid batteries and solid electrolyte are key technologies for electric powered vehicles. Thus, drastic improvement in the performance of the rechargeable batteries is strongly needed. We focused on Thio-LISICON as Li2S-P2S5 glass system. This system was already reported that has similar local structure and differential lithium ion conductivities [1-2]. We think that lithium ion conduction is influenced array of local structure as total glass structure. However, it is not clearly.
In this study, we researched the local structure of (Li2S)
x
(P2S5)
100-x
glasses (x = 67, 70 and 75). We model the atomic and electronic structure of the glasses by density functional theory and reverse Monte Carlo simulations using synchrotron X-ray diffraction, Time of flight type neutron diffraction and Raman spectroscopy data. To obtain a reliable structural model, it is worth noting that local structure information from Raman spectroscopy are included in our study. The agreement with experimental X-ray and neutron structure factors is excellent as shown in Figure 1. Intriguingly, although a characteristic difference has been reported, pair correlation functions as Li-Li is similar. Since Pair correlation function as Li-P is reflected coordination state for lithium and PxSypolyhedron as shown in Figure 2, such coordination state would influence the lithium ion conduction as an electrochemical characteristic of the glass solid electrolyte. For structure detail, we will make a presentation on the day.
In summary, we succeeded in the modeling the glass structure and discussion lithium diffusion mechanism in glass solid electrolyte.

Acknowledgment:

This work was partially supported by the RISING project of the New Energy and Industrial Technology Development Organization (NEDO).

References:

[1] Y. Onodera, et al. Journal of the Physical Society of Japan 81 (2012) 044802.
[2] K. Mori, et al. Chemical Physics Letters 584 (2013) 113–118

Figure 1