bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Humidification of Oxygen Gas on All Solid State Lithium-Air Batteries
Authors: Sakuma Shoma , Suzuki Yosuke , Imanishi Nobuyuki
Published: February 2020

1. Introduction

 All solid state lithium-air batteries have potential high energy densities and high safety without flammable organic electrolyte. However, all solid systems have intrinsic difficulty in solid-solid junction leading to low current and power densities.

 In this study, we studied the reaction mechanism of the air electrode as the first step to improve the charge-discharge capacities of the all solid state lithium-air batteries. In particular, we focused on the influence of the humidity of the air to be supplied to the air electrode.

2. Experimental

We used Li-conductive glass ceramic LATP, Ohara Co., Ltd., for solid electrolyte. Comb-shaped Pt catalyst layer was formed on the LATP base by photolithography in 50 nm thick and100μm wide with the same width spacing. The test cells consisted of lithium metal / protective film (LiTFSI/PEO) / solid electrolyte (LATP) / air electrode (Pt), which were sealed by Al-laminate sheet to form pouch cells. The cells were put in a chamber to control temperature at 60 oC and oxygen gas along with its humidity. The humidity of the gas was set at just two levels: 0% relative humidity (RH) through molecular sieve 5A, 100% RH through a bubbling bottle filled with water.

The cells were usually discharged and charged up to 20 μAh/cm2 at current densities of 1-20 μA/cm2. Reaction product was analysed after further discharge up to 2400 μAh/cm2 at 100 μA/cm2. SEM observation, XRD and XPS were used for the analysis.

3. Result and discussion

Fig.1 shows discharge and charge curves using O2 of 0% and 100% RH. Although the 100% RH cell showed reversible prescribed discharge capacity of 20 μAh/cm2, the 0% one reached the cut-off voltage of 1.5 V before discharging 20 μAh/cm2. This figure apparently demonstrates that capacity and the voltage of the cell are affected greatly by the humidity in the oxygen supplied. The open circuit voltage (OCV) after the discharge was 3.2V, suggesting Li2O2 to be the main product for the discharge reaction. XPS result also indicated that discharged product was Li2O2. Charge curve showed two plateaus at about 4.0 and 4.3 V. It suggested two processes involved in the charging reactions.

We are to present the details of the above and discharge-charge results in other relative humidity.

Figure 1
A Simple Efficient Polysulfide Anchor for Li-S Batteries
Authors: Hao Zhangxiang , Yuan Lixia , Huang Yunhui
Published: February 2020

The popularization of electric vehicles requires the development of low-cost rechargeable batteries with safety and high energy density. Lithium-sulfur (Li-S) battery stands as an important candidate for next-generation high-energy secondary batteries due to its high specific capacity, low cost and environmental friendliness. But the realization of lithium sulfur battery suffers from the poor rechargeability, low rate capability and short life span of sulfur cathode. In order to overcome the hurdles, various approaches have been proposed that can be classified into three categories: (1) confining the intermediates Li2Sx (3≤x≤8) within the cathode through material or electrode design, (2) modifying the liquid electrolyte or employing solid electrolytes, and (3) protecting the anode via coatings and electrolyte additives. Among them, some kinds of metal oxides, metal sulfides, or some two-dimensional layered materials which have strong anchoring effect for polysulfides, can immobilize sulfur species more efficiently than the widely-used carbon materials. But, most fabrication of the nano-architectured absorbents usually requires complicated procedures, which may greatly limit the manufacturability of S cathode. Herein, we report a novel polysulfides adsorption matrix for high performance Li-S batteries via a super facile process of synthesis. An ordinary commercial titanium nitride (TiN), after a simple corrosion process, can work as a high-efficiency matrix to immobilize sulfur thus a largely improved cycle stability can be achieved. Here the TiN matrix has three enormous advantages: ⅰ) a super high conductivity as 1000 S cm-1 at 298 K, ⅱ) containing polar Ti-N units which have strong binding for lithium polysulfides, and ⅲ) low cost and environmentally friendly. The S/TiN cathode, with 70 wt.% sulfur content, reveals a high initial reversible capacity of 1087 mAh g-1 at 0.5 C and a long-term charge/discharge process of 400 cycles at 0.5 C, with a decay rate of 0.19 % per cycle. Furthermore, the reversible discharge capacity is above 600 mAh g-1 even at 5 C rate.

References

[1] P.G. Bruce, S.A. Freunberger, L.J. Hardwick, J.M. Tarascon, Nat. Mater. 11 (2012) 19-29.

[2] A. Manthiram, S.H. Chung, C. Zu, Adv. Mater. 27 (2015) 1980-2006.

[3] Y. Zhao, Y. Ding, Y. Li, L. Peng, H.R. Byon, J.B. Goodenough, G. Yu, Chem. Soc. Rev. 44 (2015) 7968-7996.

Figure 1
(Invited) Predicting the Interfacial Reactions Between Cathodes and Liquid and Solid Electrolytes
Authors: Ceder Gerbrand , Richards Will , Wang Yan Eric
Published: February 2020

Very few interfaces in lithium batteries are stable at the extreme electrochemical conditions imposed on them during operation of a lithium battery. When modern layered cathode materials are charged to high voltage in liquid electrolytes they tend to lose oxygen near the surface leading to a transformation to spinel and rocksalt phases. These phases significantly increase the cathode impedance, and lead to loss of capacity and rate performance. By presenting a detailed study of the surface phases in Ni-based layered materials I will show how first principles methods can be used to model this transformation and study the growth of impedance resulting from them.

Similarly, interfacial stability is one of the most limiting issues in solid-state batteries where the liquid electrolyte has been replaced by a solid state Li-ion conductor. Most compounds that display very high Li mobility are not stable at the extreme anode and/or cathode potentials and require passivation or the use of buffer layers. I will show how these interfacial reactions can be predicted with first principles calculations. Our results confirm that very few conductors will be stable at the high voltage of the cathode material.
Failure Mechanism from Direct Contact Between Lithium Metal and Solid Electrolytes
Authors: Chung Habin , Kang Byoungwoo
Published: February 2020

The demand for lithium secondary batteries having more safety and energy density is high. In this aspect, lithium ion batteries including typical liquid electrolytes have fundamental limitations. Liquid electrolytes can cause a fire or explosion of battery and decomposition of them at high potential obstructs applying high potential cathode. Applying solid electrolyte can solve these limitations so many solid electrolytes have been interested in and researched. Major types of solid electrolytes are sulfides and oxides and their pros and cons are obvious. It is commonly known that sulfides have advantages of high ionic conductivity and softness for easy contact, while oxides have high electrochemical stability. One of the tactics that fulfill high energy density is using lithium metal directly as anode and the researches that using lithium metal on solid electrolyte are progressed. Major oxide solid electrolytes not including transition metal had been considered stable with lithium metal. However, increased resistances of lithium symmetric cell with time and all solid-state cell after charge and discharge were observed and interphase reactions with lithium metal were calculated from some solid electrolytes. However, the relationship between them and the failure mechanism of the solid electrolytes with lithium metal are not fully understood yet. In this research, we discuss the phenomena from the interphase between lithium metal and solid electrolytes; lithium aluminum germanium phosphate (LAGP) and lithium lanthanum zirconium oxide (LLZO). We also suggest the mechanism of increased resistance with direct contact of lithium metal and the solid electrolyte.
(Invited) A Three-Dimensional Li-Air Cell
Authors: Im Dongmin , Park Jung Ock , Kim Joon-Hee , Choi Kyoung Hwan , Lee Heung Chan , Park Min-Sik , Kim Mokwon , Choi Wonsung
Published: February 2020

Li-air battery features the highest gravimetric energy density among known rechargeable battery systems. The theoretical one is above 3500 Wh/kg and even practical one is foreseen to exceed 1000 Wh/kg [1]. Considering the state-of-art Li-ion battery exhibits only about 250 Wh/kg, Li-air battery is a very promising candidate as a power source for future electric vehicles. Despite very high research activities around the world, however, Li-air cell with significantly high energy density is rarely reported. To our knowledge, 150 Wh/kg reported by Kubo et al. [2] is the highest among published values. The low energy density of actual Li-air cells can be ascribed to several factors. (1) Typically a large quantity of electrolyte is employed. Unlike in the case of Li-ion batteries, the mass of electrolyte is often 10 times, 100 times heavier than active material. (2) The areal capacity is limited due to slow cathode kinetics [3]. (3) Current collectors, packaging materials, protective membranes for Li metal still occupy a large portion of cell weight. (4) Additional component such as gas diffusion layer to supply oxygen is necessary.

In this work, we designed and demonstrated a new three dimensional cell structure that can allow actual high energy density in Li-air cells. A freestanding cathode comprising activated carbon and electrolyte (polymer or ionic liquid), a polymer electrolyte membrane, and a lithium foil anode were prepared, laminated, and folded multiples times in zigzag fashion. The amount of electrolyte in the cathode was carefully controlled so that the mass ratio of electrolyte to carbon could be kept in the range 2:1 to 5:1. After the end of folding process, the cathode was exposed to one side as a whole and the anode to the other side. Gas diffusion layers (GDL) were inserted between cathode layers facing each other to supply oxygen into the inner part of cell. The depth of gas supply path through GDL was fixed at 1 cm reflecting the results of an electrochemical modeling which suggested the drop of oxygen partial pressure at the deepest part could be negligible during the entire discharge process. This novel cell structure could reduce the use of metallic current collector and packaging materials. A cell with the dimension of 1(D)x5(W)x2(H) cm was prepared, placed in a specially designed cell holder, and tested in a hermetically sealed oxygen (1 atm) chamber with a constant current of 0.24 mA/cm2 at 60oC. The energy density of the cell, based on the discharge capacity and the actual cell weight, was calculated to be ~500 Wh/kg. The details of cell design and process and the remaining issues will be presented and discussed.

References

[1] G. Girishkumar et al., J. Phys. Chem. Lett., 1, 2193 (2010).

[2] Y. Kubo et al., ECS Trans., 62, 129 (2014).

[3] V. Roev et al., J. Electrochem. Sci. Technol., 5, 58 (2014).
Cell and System Design of Lithium Air Batteries for Electric Vehicles
Authors: Ryu Hee-Yeon , Rhee Junki , Ryu Kyoung Han , Lee Ho-Teak
Published: February 2020

Many studies have been carried out on the lithium-air batteries due to their high theoretical specific energy. The results have been published in the range of scientific papers: electrolytes, catalysts, cathode materials and structures, lithium anode and their fundamental reaction mechanisms for the last ten years. Recently a few researchers have published their analysis for the system level considerations for lithium-air batteries to reach long-term automotive applications.

Even though there are still many scientific challenges such as poor cyclability and low energy efficiency, we focused on a cell and system design of lithium-air batteries for electric vehicles to investigate their practical achievable specific energy and energy density. For this purpose, a cell size of 270 x 100 mm2 was fabricated and tested their electrochemical performance. We also designed a novel multi-cell stack structure including bipolar plates for the optimal air distribution. A lithium-air 13Ah cell stack was made and tested their electrochemical performance. The details will be discussed in the PRiME 2016.
Layer By Layer Based Multifunctional Biointerfaces-Design and Applications
Authors: Arugula Mary , Zhang Yuanyuan , Simonian Aleksandr
Published: February 2020

Scaffolding of different functionally active biopolymers on CNTs and their further layer-by-layer (LbL) assembly on the appropriate interfaces allow formation of new insights and concepts for the development of multiple novel technological biointerfaces. We concentrate on how several different enzymes assembled at the same interface by the LbL technique can operate in different modes in the construction of novel bioelectronic applications. The focus of our study was to design unique multifunctional devices for biomedical, environment and energy applications. LbL based enzyme/CNTs nanocomposites were used in discriminative detection of organophosphate and non-organophosphate pesticides. The system was fabricated based on electrostatic interactions between negatively charged multiwall carbon nanotubes (MWCNT)/­ acetylcholinesterase (AChE) enzyme and positively charged MWCNT/ organophosphorus hydrolase (OPH) enzyme along with a set of cushioning bilayers consisting of MWCNT-­PEI (positive charge) and MWCNT­-DNA (negative charge) on glassy carbon electrodes. Furthermore, we explored the feasibility of simple renewal process to restore inhibited AChE enzyme activity for multiuse and reusable applications. Upon renewal of the sensor the system demonstrated more than 95% signal recovery and good stability. Additionally, we extended LbL approach for biofuel cell applications. A bioanode based on MWCNTs immobilized invertase (INV) and glucose dehydrogenase (GDH) cascade were alternatively assembled. Our idea was to use layer by layer approach to fabricate bioanode using conventional electrodes, with small surface areas, less enzyme loading, sequential arrangement of enzymatic layers that would enhance the power generation. We used different kinds of sensor surfaces and electron transfer mediators to improve the performance of the biofuel cell.
Real-Time, in Situ Monitoring of Nitric Oxide and Hydrogen Peroxide Generated By Non-Thermal Plasma Irradiation: Use of an Amperometric Microsensor Array
Authors: Shin Somin , Shin Jae Ho , Jeon Seongsil , Park Gyungsoon
Published: February 2020

Plasma is high energy electromagnetic radiation. Recently a non-thermal plasma treatment has been employed in emerging new biomedical applications, including bacterial decontamination and chronic wound treatment. Such antimicrobial and healing efficacies may be related to the formation of reactive oxygen and nitrogen species (ROS and RNS; e.g., OH·–, O2·–, NO, ONOO·–, and H2O2) by plasma treatment. Among several reactive species, nitric oxide (NO) has been extensively studied due to its phagocytic and antithrombotic activities, and angiogenic property. In addition, hydrogen peroxide (H2O2), another major species produced by plasma treatment is implicated as the main transmitter of a redox signal in several biological processes. To elucidate bioplasma science, it is essential to real-time, in-situ determine NO and H2O2 produced during plasma treatment and their generation kinetics. Herein we report on a microsensor array to selectively detect NO and H2O2 generated by non-thermal plasma irradiation, respectively. Two working electrodes (Pt for NO sensing and Pt/aniline derivative for H2O2 sensing, respectively) are modified with a perfluorinated xerogel as a permselective membrane to improve sensor’s selectivities over readily oxidizable interfering species and other ROS and RNS. In addition, the effect of the plasma gas composition (O2/N2 ratio) on NO/H2O2 production ratio will be studied. Finally the microarray sensor will be employed to determine NO and H2O2 generation during plasma irradiation in biological milieu in vivo or ex vivo.
Electrochemical Detection of Neurotransmitters Using Modified PEDOT Electrodes
Authors: Gruia Violeta-Tincuta , Efimov Igor , Ispas Adriana , Bund Andreas
Published: February 2020

This paper presents recent results from authors’ labs on the electrochemical detection of ascorbic acid (AA), serotonin (5-HT) and dopamine (DA) at poly[3,4-ethylenedioxythiophene], PEDOT, and PEDOT-Au electrodes.

We could show that the technique used for preparing the PEDOT and the PEDOT-Au electrodes strongly affects the quality of the sensors. Pulse plating gave the best films with regard to their morphology and charge storage. Parameters of the pulse sequence, such as anodic and cathodic potentials, as well as pulse duration, were optimized.

Acoustic impedance data (obtained by an Electrochemical Quartz Crystal Microbalance in dispersive mode) show that such films prepared by pulse plating display also maximal elastic storage and loss moduli.

The detection limits for the above mentioned neurotransmitters were studied by differential pulse voltammetry in phosphate buffer solution, PBS (Fig. 1), in the presence and absence of AA.

Compared to pristine PEDOT, the Au modified electrodes showed a considerable increase of sensitivity and selectivity for neurotransmitters detection.

Fig. 1. The DPV curves measured in PBS with different concentrations of (a) 5-HT and (b) DA, on PEDOT layers in the presence of 300μM AA

Figure 1
Disposable Plasmonic Plastic SERS Sensor Using Gold Nanoparticles Arrays
Authors: Song Minwoo , Lee Dooyong , Park Hee Jung , Lee Seunghyun
Published: February 2020

Our ultimate goal of this study is to form a monolayer of plasmonic anisotropic gold nanoparticles on the surface of disposable plastics via chemical processes to use LSPR sensor. The process creates hydroxyl group by method of plasma cleaning or piranha treatment, subsequently substitute hydroxyl groups for Amine functions by using amino silane solution. Then, the surface is coated with the gold nanoparticles. For the plasmonic gold nanoparticles, gold bipyramids (Au BPs) and gold nanorods (Au NRs) with a surfactant, cetyltrimethylammonium bromide (CTAB) bilayer were employed. Then, their surfaces were modified with methoxy polyethylene glycol thiol (mPEG-SH). Based on these plasmonic gold nanoparticle substrates, we have investigated adsorption sensitivity and kinetics of self-assembly of thiolated organic molecules.
Development of Insect Derived Protein Based Electrochemical Impedance Biosensor Platform
Authors: Rong Yue , McLamore Eric S , Keyhani Nemat O
Published: February 2020

This project utilize a novel set of proteins derived from insects including tsetse fly and fire ants as the recognition element in a biosensor. Highly sensitive mechanisms of chemical perception is one of the most recognized features of insects. In the antennae, maxillary palp, proboscis, legs, and wings, odorants are perceived by odorant receptors. These olfactory organs are covered with sensilla which are sensory hairs that bathed in an aqueous lymph and contains small soluble olfactory proteins, chemosensory proteins (CSPs). CSPs are mediators of the initial interactions with odorants that facilitate transport of odorants from the external environment to olfactory receptors (OR) on the dendritic membrane of sensory neurons. CSPs were extracted from Solenopsis invicta (Si, red imported fire ant) and Glossina morsitans morsitans (Gmm, tsetse fly) and then multiply His-tagged. Initial work is focused on measuring the protein immobilization process by metal histidine binding and create a baseline for target molecules characterizations. CSPs were self-assembled on platinum/iridium electrodes via polyhistidine-platinum covalent bonding. CSP immobilization followed Langmuir kinetics, with K values ranging from 0.22 to 0.35 mg cm-2. This was validated using measurements of electroactive surface area from cyclic voltammetry (CV) and the charge transfer resistance from electrochemical impedance spectroscopy (EIS). To further expand on this initial work, amorphous platinum nanoclusters were formed by pulsed sonoelectrodeposition. This nanoplatinum layer increased the electroactive surface area by an approximately four to five times, which is consistent with published research. The increase in physical surface area resulted in a slight increase in CSP loading based on a Langmuir adsorption model (K values on nanoplatinum-modified electrodes ranged from 0.18 to 0.25 mg/cm^2). Ongoing work is testing the sensitivity of these electrodes for volatiles compounds relevant to agricultural, environmental, and medical applications. These preliminary results represent the first major step toward engineering CSP-based biosensors for detecting volatiles.
Ag-Coated Polymeric Nanopillar Array for Quantitative Chemical Sensing By Surface-Enhanced Raman Spectroscopy
Authors: Kim Anna , Kim Hyun-Jong , Lee Ho-Nyun , Yoo Bongyoung , Lim Hana
Published: February 2020

Surface-enhanced Raman spectroscopy (SERS) is undoubtedly one of the most useful physical chemistry techniques for highly sensitive molecular detection. It is now well understood that the plasmonic coupling effect at the nanometer gap junction between particles induces enormous electromagnetic enhancement that allows SERS signal to be detected with single-molecule sensitivity. However, the applications of SERS in quantitative detection are still far from well established, due to the difficulty in obtaining reproducible SERS substrates, and hence the SERS signal intensities. Therefore, fabrication of highly reliable SERS substrates is a significant part of SERS development.

In this study, we provide a simple, low-cost method, based on the production process of nanoporous anodic aluminum oxide (AAO), to fabricate polymeric nanopillar structure which can be used as high sensitivity SERS substrate. In details, the nanoporous anodic aluminum oxide was used as the template for the fabrication of uniform nanopillar array. The ordered nanopillar array was successfully realized by pouring acrylate monomer into the AAO template and subsequential curing. The shape of nanopillar was carefully controlled by periodical modulation of anodizing and pore widening. And, to produce electric field for SERS, Ag nanoparticles were coated on the nanopillar array. Various chemicals, such as rhodamine 6G and some proteins, on the Ag-coated nanopillar array were detected by SERS.

The Ag-coated polymeric nanopillar substrate provided higher sensitivity of SERS spectra for various chemicals than Ag-coated flat polymeric substrate (without nanopillar). As the diameter of nanopillar was controlled by anodizing voltage accordingly, changes of nanogap size caused different SERS signal sensitivity. Furthermore, the shape of nanopillar, thickness of Ag-coated layer, and aging temperature were interestingly crucial factors for the improvement of sensitivity and reproducibility of SERS signal.
Fabricating a QCM Device with the Nanostructures Using the AAO Template
Authors: Asai Naoto , Ito Takeshi , Shimizu Tomohiro , Shingubara Shoso
Published: February 2020

Quartz Crystal Microbalance (QCM) method is one of promising approach to detect gas molecules and bio materials since it has advantages in real time measurement, high sensitivity, and portability. However, the method shows poor sensitivity to low molecular weight materials because of its measuring principle, mass change. To improve the sensitivity to the low molecular weight materials, we introduce to fabricate nano structures on the quartz crystal. As the results, the surface area derived from nano stractures to bind with analytes is greatly improved.

Anodizing Aluminiun Oxide (AAO) is known as a one of attractive functional materials which has self assembled nano structure provided by anodizing highly-pure Aluminium in the acid solutions, for examples, oxalic acid and sulfuric acid. The nano structure of AAO is controllable by the anodizing condition such as voltage, anodizing time, and the acid solutions. Then, we can get the regularly arranged pores with high aspect ratio. Our nano structures on the quartz crystal were referred from the AAO nano structure.

Figure 1 shows the nanowires array composed of Au. The nanowires were fabricated on a SiO2 substrate. The shape of the nanowire was evaluated by Scanning electron microscopy (SEM). Average of the height and the diameter of the nanowire was 1 μm and 70 nm, respectively. As the results, we could get the aspect ratio more than 14. In fact, large surface area was achieved on the quartz crystal. By using our process, nanowire positions would be arranged in three angles lattice. This manufacture procedure to fabricate Au nanowire arrays used electrical plating, so it enables to fabricate arbitrary nanowire arrays to suit someone’s measurement needs by changing the plating solution. To detect antigen-antibody reaction, we manufactured Au nanowires that have a high affinity with protein and the cell because of thiol linkage. Our fabricating process was written below.

Ti/Au/Al (30/100/1000 nm thick, respectively) was sputtered on the SiO2 substrate by using a DC magnetron sputtering equipment. AAO was obtained by anodizing the Al thin film with Pt plate (cathode) with applied voltage of 40 V in 0.3 M oxalic acid. Then, the sample was immersed in 0.3 M phosphoric acid to expand pores size and to remove the barrier layer which was located on the AAO bottom. The sample was electrodeposited at constant current of 0.004 mA/mm2 using Au plating solutions. Finally, regularly arranged nanowires were obtained by removing AAO in 1 M phosphoric acid. By this manufacture procedure, we fabricated nanowires structure on the sensor electrode and tried to detect the antigen-antibody reaction using the QCM method which had nano structures on the quartz crystal. In the conference, we will show the result about the comparison measurement.

Figure 1
Impedance-Based Biosensing Using Virus-Poly(3,4-ethylenedioxythiophene)
Authors: Ogata Alana , Schlegel Shae , Briggs Jeffrey , Tan Ming , Weiss Gregory , Penner Reginald
Published: February 2020

Urinary bladder cancer is a worldwide issue that calls for critical attention of effective biosensors for early cancer detection. The advent of virus-biosensor technology presents a promising and non-invasive solution by quantitatively detecting bladder cancer using electrical resistance-based measurements. Virus-biosensor films are prepared by incorporating M13 bacteriophage (phage) into a conductive polymer, poly 3,4-ehtylenedioxythiophene (PEDOT), on the surface of gold electrodes using electrodeposition. M13 bacteriophage are modified to display peptides for specific, high affinity binding to targeted biomarkers. The electrochemical impedance of virus-PEDOT films increases upon exposure to target biomarkers that selectively bind to the corresponding M13 bacteriophage. Changes in the real component of the impedance are observed for a broad range of frequencies, 5 Hz to 50 K Hz. These data show virus-PEDOT biosensor films follow a dose-response relationship over a subnanomolar to micromolar concentration range. These results show enhanced detection of arbitrary cancer biomarkers using modified viruses and can be expanded to general biosensing applications.
Ultrasensitive Biosensors Based on Redox Cycling
Authors: Yang Haesik
Published: February 2020

High signal amplification is essential for ultrasensitive detection of biomolecules. In recent years, we have developed new redox cycling schemes combined with enzymatic amplification that allow high signal amplification in a simple format along with low background levels. To minimize unwanted side reactions, a new concept that outer-sphere-reaction-philic species can react slowly with inner-sphere-reaction-philic species was applied. In this presentation, the signal amplification based on (i) electrochemical-chemical (EC) redox cycling using a reducing agent, (ii) electrochemical-chemical-chemical (ECC) redox cycling using a reducing agent and an oxidizing agent, and (iii) electrochemical-enzymatic (EN) redox cycling using a redox enzyme will be introduced. Moreover, our efforts for practically useful biosensors (lateral-flow immunosensors and washing-free immunosensors) will be presented.

 References

[1] A.-M. J. Haque, J. Kim, G. Dutta, S. Kim, H. Yang, Chem. Commun., 51, 14493 (2015).

[2] S. Park, A. Singh, S. Kim, H. Yang, Anal. Chem., 86, 1560 (2014).

[3] A. Singh, S. Park, H. Yang, Anal. Chem., 85, 4863 (2013).

[4] M. R. Akanda, T. Vellaiappillai, S. Park, K. Jo, M. Hyun, H. Yang, Anal. Chem., 85, 1631 (2013).

[5] H. Yang, Curr. Opin. Chem. Biol., 16, 422 (2012).

[6] M. R. Akanda, Y.-L. Choe, H. Yang, Anal. Chem., 84, 1049 (2012).

[7] M. R. H. Akanda, M. A. Aziz, K. Jo, V. Tamilavan, M. H. Hyun, S. Kim, H. Yang, Anal. Chem., 83, 3926 (2011).
Sensor Design and New Material for an Intelligent System for People with Musculoskeletal Tension Problems
Authors: Plaza Mauricio , Aperador Willian , Cifuentes Mauricio
Published: February 2020

The purpose of the current research is the use of new materials and sensors for the Design supports system, reducing efforts for people with problems on musculoskeletal system. The problem also include the damage prevention in back and spine, due for transport of heavy loads on military activities, or activities that include heavy elements transport.

The need of transport of heavy elements in certain professional areas, has developed the advancement of transportation devices, in order to avoid temporary injury and discomfort that can range from a few hours, to resentment in the bone tissue and Muscle permanently. This case is even more common on military staff, since the military exercise normally requires mobilizing survival equipment, ammunition, ballistic, computer and communication systems, over long distances, which often exceed the resistance limits of the soldiers, causing temporal harm in most cases, but can become permanent without proper care.

The specific objective of this research is to use physiological measurements and modern design techniques for the construction and validation of a novel ergonomic system for people with musculoskeletal problems, to avoid injury in back and spine, without degrading performance in work or proper military exercise by increased comfort and   strength of musculoskeletal system of the soldiers and workers; using methods that promote improvements in critical aspects of the exercise of mobilization of heavy loads, with better load distribution  in different parts of the body and an external support. This technology is often used for people with musculoskeletal damage.

The use of special adapted sensor systems allow  measuring physiological conditions allow improving results regarding the models used currently (suitcases, backpacks, belts, etc.), allowing  focus in the design process,  reducing injury rates and the distribution load in accordance with the nature of it, the type of support in which this is to mobilize and phenotype of the Colombian population.

The design process will be addressed by searching of optimization of the cost and improvement of the physical and functional characteristics of the prototype, by making harmless and noninvasive tests on potential end users and taking account of expert opinions, to ensure that the prototype provides protection and support expected.
Ultra Stable Dual Functionalized Gold Nanoparticles for the Effective Colorimetric Detection of Clenbuterol
Authors: Simon Turibius , Lin Ching-Chang , Ko Fu-Hsiang
Published: February 2020

Clenbuterol, a medium cumulative drug also appears as residues in animal would cause dizziness, fatigue, arrhythmia, and metabolic disorders in humans if eaten.1 Illegal abuse of clenbuterol was not stopped eventhough it has been banned from adding to animal feeds in many countries.2 Clenbuterol incident at Shanghai Co. (March 2011) caused great concern worldwide.3 Therefore, recently many sensor probes have been developed for the detection of clenbuterol. Among them, gold nanoparticles based detection was found to be promising.4, 5 However, to the best of our knowledge, dual functionalized AuNPs have not been reported for the detection of clenbuterol. Henceforth, we tend to develop ultra stable dual functionalized AuNPs for the effective detection of Clenbuterol (CLB).

These newly ultra stable dual functionalized PE-Glu-AuNPs were developed by functionalization of AuNPs with Glutamic acid (Glu) and poly ethyleneimine (PE)via NaBH4 reduction method. We have elucidated the stability of PE-Glu-AuNPs over a period of six months. Further, the colorimetric assay of PE-Glu-AuNPs to CLB revealed that, its selective sensing ability starts from 300 nM visualized through naked eyes at pH 5. Additionally, the sub nanomolar detection of CLB has been estimated from linear fittings and standard deviation of UV-vis titration. The reaction mechanism was further verified through TEM images and dynamic light scattering (DLS) data. By DLS analysis, the initial size of PE-Glu-AuNPs was calculated to be 12.8 ± 8.6 nm, which later aggregated as 84.8 ± 52.3 nm during the detection of CLB-(C). It has also been well demonstrated that the probe does not evidence the selectivity towards any other interferences (A-Alamine; B-Phenylalanine; D-Nacl; E-CaCl2; F-Threonine; G-Cysteine; H-Glycine; I-Glucose and J-Urea). Moreover, the aggregation induced detection of CLB was well confirmed by TEM studies.  

References

Brambilla, G.; Cenci, T.; Franconi, F.; Galarini, R.; Macrì, A.; Rondoni, F.; Strozzi, M.; Loizzo, A. Toxicol. Lett. 2000, 114, 47−53.

Wu, K. S.; Guo, L.; Xua, W.; Xu, H. Y.; Aguilar, Z. P.; Xu, G. M.; Lai, W. H.; Xiong, H.; Wan, Y. Q. Talanta
2014, 129, 431−437.

Yan, H.; Xu, D.; Meng, H.; Shi, L.; Li, L. Qual. Assur. Saf. Crops Foods
2015, 7, 27−35.

Zhang, X. F.; Zhao, H.; Xue, Y.; Wu, Zh. J.; Zhang, Y.; He, Y. J.; Li, X. J.; Yuan, Zh. B. Biosens. Bioelectron.
2012, 34, 112−117.

Kang, J.; Zhang, Y.; Li, X.; Miao, L.; Wu, A. ACS Appl. Mater. Interfaces
2016, 8, 1−5

Figure 1
Fabrication of the TiN-Ag Double-Shell Hollow Nanosphere Structure As the Highly Sensitive Substrate
Authors: Ban Rongcheng , Yin Jun , Li Jing
Published: February 2020

Surface plasmon resonance (SPR) effect has been intensively studied in recent years due to its wide applications in sensing or optical regimes, such as surface-enhance Raman scattering (SERS) for molecular detection 1, 2, plasmonic optical tweezers3 and so on. It has been well accepted that the noble metals, such as Ag and Au, especially Ag, are the ideal plasmonic materials in SERS detection 4. But, Ag generally exhibits poor chemical and thermal stability, which would deteriorate its SERS activity5. So, alternative plamonic materials or passivation strategy were often proposed to resolve those issues. TiN, besides its good chemical stability, high melting point, and high hardness as other metal nitrides, also exhibits a metal-like optical properties in the visible and longer wavelengths6, 7 and thus might be considered as a potential plasmonic material.

In this work, the surface modification on Ag hollow nanosphere (HNS) arrays was carried out by coating a thin layer of TiN, which presents high and stable sensitivity on molecular detection, including R6G and b-agonists. Theoretically and experimentally, it has been founded that the TiN coating layer can effectively manipulate the local field distribution and intensity near the Ag HNS, as well as the multiple plasmonic resonances on the composite hollow structure.8 Further Raman characterizing indicated that the multiple coupling effect between the plasmonic cavities and the charge-transfer process between the TiN/Ag shells enable the substrate to be a good SERS substrate with intensively enhanced local filed and Raman activity comparing with the bare Ag HNS arrays.

References

1. J. Yin, Y. Zang, C. Yue, Z. Wu, S. Wu, J. Li and Z. Wu, J. Mater. Chem., 2012, 22, 7902-7909.

2. Y. C. Cao, R. Jin and C. A. Mirkin, Science, 2002, 297, 1536-1540.

3. M. L. Juan, M. Righini and R. Quidant, Nature Photonics, 2011, 5, 349-356.

4. P. Huang, J. Lin, W. Li, P. Rong, Z. Wang, S. Wang, X. Wang, X. Sun, M. Aronova, G. Niu, R. D. Leapman, Z. Nie and X. Chen, Angewandte Chemie, 2013, 52, 13958-13964.

5. Y. F. Huang, M. Zhang, L. B. Zhao, J. M. Feng, D. Y. Wu, B. Ren and Z. Q. Tian, Angewandte Chemie, 2014, 53, 2353-2357.

6. G. V. Naik, V. M. Shalaev and A. Boltasseva, Advanced materials, 2013, 25, 3264-3294.

7. A. Boltasseva and H. A. Atwater, Science, 2011.

8. J. Yin, Y. Zang, B. Xu, S. Li, J. Kang, Y. Fang, Z. Wu and J. Li, Nanoscale, 2014, 6, 3934-3940.
Fabrication of Nanopore on Electron Beam Induced Membrane for Single Molecule Analysis
Authors: Choi Seong Soo , Park Myoung Jin , Yamaguchi Tokutaro , Han Chul Hee , Oh Sae-Joong , Park Kyoung Jin , Yoo Jung Ho , Kim Yong-Sang , Park Nam kyou
Published: February 2020

Recently there have been considerable interests about the fabrication of nanopore array for optical detection of single molecule analysis. So far, the nanopores on the SiN or graphene membrane were fabricated and utilized for genome sequencing with an electrically driven and electrical detection technique. We report fabrication of nanopore formation on pyramid by using focused ion beam technique and electron beam irradiation techniques. Under electron beam irradiation on the specimen, carbon incorporation with electron beam is reported, hence, the diffused membrane is believed to be amorphous carbon so far. However, we found that the membrane formed contains Au atoms. We found that the Au nanoparticles formed on the diffused membrane by using HRTEM (high resolution transmission electron microscopy). After the samples were kept under the room environments for several months, and up to one year, Au particles were formed on the diffused membrane. Au atoms less than 1 nm on the diffused membrane, the Au atoms cannot be detectable due to HR-TEM resolution limit.  The larger particles grow bigger and bigger with expense of smaller particles via Ostwald ripening. We also observed bi-stable phases of Au particles during electron beam irradiation process via Spinodal decomposition. Fabricated nanopore integrated with Au particles can be utilized as optical nanopore for single molecule analysis.
Thin Film Surface Chemo-Resistivity Tuning Using Metal Deposition Via Slrr
Authors: Ahmadi Kamyar , Wu Dongjun , Monteiro Othon , Brankovic Stanko R
Published: February 2020

The interaction of SH-, or S2- with Au surface has been phenomenon of considerable interest in last decade. The Au-S adsorption bond was studied as convenient linker for many complex molecules such as alkane-thiols, proteins, 3D molecular structures for molecular electronics, or for biological sensors applications [[1]]. The adsorption of SH-, or S2- to the Au is enabled by formation of strong S-Au bond (few eV energy) [[2]], which is stable in a wide potential range from Au surface oxidation (1.2 V vs. SHE) to reductive dissociation of Au-S bond (~-0.6 V vs. SHE). The change in the energetics of the surface states due to HS-, S2- adsorption does affect the surface resistance of ultrathin Au films. This effect is mainly due to S-adsorbate induced changes to quality of electron scattering from the surface states [[3]]. Therefore, an adsorption process of SH-, or S2-on Au can be indirectly observed by measuring the change in the overall resistance of the Au thin films.

In this talk we will present data studying chemo-resistive properties of Au ultrathin films exposed to solutions containing Cl- and HS- ions in 0 – 100 ppm range, Figure 1. The surface modification of these films was done by deposition of few monolayers of Au, Pd and AuPd via SLRR of Pb UPD [[4]]. The change in resistivity of Au films as a function of the solution composition was measured by AC method in order to minimize the effect of parasitic current path through the solution. As deposited Au films showed very small surface chemo-resistance while the films modified by few monolayers of Au, Pd and AuPd deposit have shown much better performance. To analyze our data we have developed comprehensive analytical model which links the adsorption process of different anions from the solution to the change in the diffused scattering coefficient for electrons from the surface [[5]]. Experimental results and analysis show that modifications of the Au surface, with several monolayers of Au and Pd, increases probability for electron scattering from the surface and improves the chemo-resistance of ultrathin Au films. The significance of our findings is discussed for chemical sensors design shining a new light on the importance of surface preparation for chemo-resistive sensor performance, Figure 1.  

The authors acknowledge the support from Baker Hughes Corporation and NSF Chemistry division under the contract # 0955922.

[1] Nanoelectronics, Nanowires, Molecular Electronics, and Nanodevices, K. Iniewski, Mc Graw Hill, New York (2013).

[2] Y. Jin, C. Yu, R.J. Denman, W. Zhang, Recent Advances in Dynamic Covalent Chemistry, Chemical Society Reviews
42, 6634 (2013)

[3] Ultrathin Electrochemical Chemo- and Biosensors, eds. O.S. Wolfbeis, and V. M. Mirsky, Springer (2013), p. 120

[4] S. R. Brankovic , J. X. Wang and R.R. Adzic, Surface Science , 474, L173, (2001).

[5] E. H. Sondheimer, Advances in Physics, 1, 1 (1952).

Figure 1
(Keynote) Quantum Biophotonics and Its Applications in Life Sciences and Medicine
Authors: Lee Luke
Published: February 2020

In this talk, I will present quantum biophotonics for fundamental life sciences and translational precision medicine. First, I will introduce a quantum nanoscope that allows non-invasive optical imaging of electron-transfer (ET) dynamics in live cells. The quantum nanoscope is designed to capture the real-time ET imaging of enzymes using Plasmon Resonance Energy Transfer (PRET) mechanism and quantized plasmon quenching dips in resonant Rayleigh scattering spectra. Second, I will discuss photonic gene circuits for noninvasive gene regulations in living organism and gene therapy. Since the activation of transcription factor NF-kB plays a central role in the regulation of inflammation, immune responses, infections, differentiation, proliferation, oncogenesis, and apoptosis, precise spatiotemporal controls of NF-kB signaling pathway by optically addressable siRNA-antennas will have significant implications in precision medicine. Third, I will discuss the important role of bionanophotonics in integrated molecular diagnostic systems (iMDx) for personalized precision medicine, and microphysiological analysis platforms (iMAPs) for drug discovery and regenerative medicine. The iMDx comprises three key elements of precision medicine on chip: ultrafast multiplexed photonic PCR for the early detection of DNA and RNA biomarkers in blood, signal amplifications of protein markers, and a self-contained sample preparation from whole blood on chip, which allows a sample-to-answer readout platform. The progress on patient-specific iPSCs-based iMAPs, pancreatic islets and mini-brains on chip will be discussed along with the vision of preventive medicine via precision engineering in medicine.
Modeling and Characterization of Electroformed MEMS Variable Capacitors for Cobalt Iron Magnetostriction Measurements
Authors: Langlois Eric Donald , Finnegan Patrick , Ballance Mark Harry , Pillars Jamin Ryan , Monson Todd , Hollowell Andrew E , Arrington Christian L. , Pearce Charles Joseph , St. John Christopher R.
Published: February 2020

Electroplated CoFe alloys demonstrating Joule magnetostriction (i.e., a large change in material shape induced by an applied magnetic field) have been recently developed for the creation of microfabricated magnetoelastic resonators for tagging applications. This development requires a measurement technique for evaluating film magnetostriction performance to provide feedback for optimization of the electrodeposition process. This technique must be suitable for electrodeposited films in terms of thickness and ease of processing, have the required sensitivity and dynamic range for accurate microstrain measurements in low magnetic fields up to saturation, and be cost competitive with commercial instruments. A new MEMS variable capacitor has been developed for this purpose that incorporates electroformed mechanical and electrical features as well as the electrodeposited film under test. This capacitor has a modeled 3 pF variable range covering microstrains up to 200 ppm. This presentation will cover the design, modeling, and characterization of these capacitors for magnetostriction measurements of CoFeB and CoFe electrodeposited films. This will also include a discussion of a custom printed circuit board for extracting capacitance signals during the magnetic field ramp inside of a superconducting quantum interference device (SQUID) magnetometer.
New Top-Down Approach for Fabricating Si-Based Nanostructures
Authors: Meng Lingkuan , He Xiaobin , Gao Jianfeng , Li Junjie , Wei Yayi , Yan Jiang
Published: February 2020

We propose a novel CMOS-compatible top-down nanofabrication technique of highly-ordered Si-based nanostructures using a single amorphous silicon (α-Si) material. The pattern of α-Si layer is precisely transferred into the underlying SiO2 material. Then, various well-controlled SiO2nanostructures fabricated by this approach can be used as nanotemplates to transfer into the underlying substrate materials such as silicon, germanium, transistor gate or other semiconductor materials to fabricate specifically required nanostructures by RIE processes.

To the best of our knowledge,it is the first time for α-Si film used as an etch mask to fabricate Si-based nanostructures including nanoline, nanotrench, nanohole and nanofin arrays. It is observed that the α-Si mask can significantly reduce the pattern edge roughness and achieve highly uniform and smooth sidewalls. This behavior may be attributed to presence of high concentration of dangling bonds in α-Si material surface. By controlling the process condition, it is possible to achieve desired vertical etched profiles with precisely controlled sizes. In addition, our results indicate that silicon nanostructures can be further trimmed to smaller than 10nm by combing with assisted post-treatment methods such as H2anneal process. For bulk Finfet devices, the size of top CD of silicon nanofins around 5nm have been easily achieved via this method.

Our results fully demonstrate a great potential of α-Si material in the fabrication of a large number of Si-based nanostructures. Moreover, the novel top-down approach is a potentially universal method that is fully compatible with the current existing Si-based CMOS technologies. It will be expected a new emerging and disruptive technology with low process complexity and high throughput compared with existing silicon fabrication techniques, and it offers a greater flexibility for the fabrication of various nanoelectronics, biosensors and optoelectronic devices in a cost-effective and efficient way.

Figure 1