bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Closed Bipolar Electrochemistry for Sensor and Bioimaging Applications
Authors: Inoue Kumi Y. , Iwama Tomoki , Fakhruddin Siti Masturah , Shiku Hitoshi , Matsue Tomokazu 
Published: December 2020

Closed bipolar electrochemistry (cBPE) involves simultaneous oxidation and reduction at the opposite poles of a conductor located in two separated solutions. This unique property is expected to be used as new electrochemical analytical tools including sensors and imaging platforms. I will introduce our researches for application of cBPE to sensors and bioimaging.
Our first application of cBPE is in a sensor device for liquid-junction-free substitutional stripping voltammetry (SSV) (Figure A) [1]. SSV is a method for highly sensitive amperometric measurement by integrating small oxidation current over time as a silver deposition. A general SSV uses a galvanic-like cell with a liquid junction to convert an oxidation current generated in one cell into silver deposition in the other cell. Then, the amount of silver deposition is quantified by stripping voltammetry. As an idea of eliminating the liquid junction prohibiting the miniaturization of the SSV device, we proposed a method using conductor alternative to liquid junction to obtain electrical continuity between two cells. I later realized that this configuration is the cBPE. We also applied cBPE to unique amperometric sensors including simultaneous multiple measurement device (Figure B) [2] and probe-type device integrating a reference electrode [3].
Our second application of cBPE is in an electrochemical imaging platform. In order to realize an electrochemical microscope for real-time bioimaging with single-cell level spacial resolution, we have employed closed bipolar electrode array with electrochemiluminescence (ECL) detecting system (Figure C). As a first demonstration, we successfully obtained an image of flowing [Fe(CN)6]3- ions on a cBPE array fabricated by bundling Au wires (200 µm in diameter) at a frame rate of 10 fps [4]. Then, a higher density cBPE array of which interval was 35 µm pitch on average was fabricated via electroless plating on a micropore membrane without any photolithographic technique. Using this cBPE array, difference in respiratory activity of a live and a dead MCF-7 spheroids was successfully imaged as oxygen distribution on the cBPE array.
Now we are on a research of operation of liquid junction free sensor using cBPE as well as researches for expanding the application of the cBPE based imaging platform. These studies are expected to further expand the possibilities of bipolar electrochemistry.
References:
[1] Shinichiro Takano et al., Electrochem. Commun., 66 (2016) 34-37.
[2] Kumi Y. Inoue, et al., ChemElectroChem, 5 (2018) 2167-2170.
[3] Siti Masturah binti Fakhruddin, et al., Electrochem. Commun., 93 (2018) 62-65.
[4] Tomoki Iwama, et al., Chem. Lett., 47 (2018) 843-845.

Figure 1
Electrochemiluminescence-Based Detection of Cell Surface Biomolecules By Using Cup-Shaped Microelectrodes
Authors: Kuriyama Airi , Kamata Tomoyuki , Kato Dai , Kojima Naoshi , Yamamura Shohei , Kim Hyonchol 
Published: December 2020

Identification of biomolecules expressed on a cell surface is important, because their expressions usually imply condition of the cell, and fluorescence-based labeling and detection is one popular method for the identification of such molecules. In the method, specific antibodies are conjugated with fluorescent dyes, target molecules are reacted with the fluorescent antibodies, and expressions of the target molecules are identified with fluorescence observation. This method is target-specific and highly sensitive, however, detection sensitivity of the method is sometimes still insufficient. For example, one problem for the identification of circulating tumor cells (CTCs) is false-negative results caused on the missing of cancer cells on which target marker molecules are few expressed. Using of electrochemiluminescence (ECL)-based detection is one useful way to improve the sensitivity [1], however, ECL can be only irradiated from very close position of the electrode, and detection of cell surface molecules by ECL-based method is difficult because of large size of cells.
We propose a new method to detect cell surface biomolecules with ECL-based method by using cup-shaped microelectrodes. The hemispherical electrodes were composed of thin double layer [2], and in detail, the inner concave was low noise nano-carbon layer [3] and the outer was nickel. Diameter of the cup was almost the same as that of general animal cells [4], therefore, large area of the cell can be closely approached to the electrode surface with capture of the cell to inner concave of the cup. Epithelial cell adhesion molecule (EpCAM), which is a famous marker molecule for the identification of CTCs, was used for a model target in this study, and a human breast cancer cell line on which EpCAM was low expressed (MDA-MB-231) was used for the evaluation of EpCAM detection by ECL-based measurement. ECL probe (ruthenium(II) tris(bipyridine))-conjugated anti-EpCAM antibody was reacted with the cancer cells, the labeled cells were captured to inner concave of the cup-shaped microelectrodes, and ECL observation was performed. When electric voltage was applied, ECL was observed from cups in which cancer cells were captured. These results indicate that ECL-based detection of cell surface molecules can be achieved by using cup-shaped microelectrodes with quite high detection sensitivity.

References

[1] M. Liang et al., Assay Drug Dev. Technol., 5, 655 (2007)
[2] H. Kim et al., Jpn. J. Appl. Phys., 50, 06GJ03 (2011)
[3] O. Niwa et al., J. Am. Chem. Soc., 128, 7144 (2006)
[4] H. Kim et al., Sci. Rep., 4, 6362 (2014)
A Non-Invasive Cell Death Monitoring Based on an Automatic High-Throughput Cell Capacitance Measurements
Authors: Fanjul Pablo , Izquierdo-Bote Daniel , González-García María Begoña , Chacón Manuel , Suarez Lorena , Sánchez Manuel , Hernández-Santos David 
Published: December 2020

In vitro cell death process monitoring is a method widely used in medical and pharmacological studies to know the effect of drugs and toxins on tissue models. This work presents a study of cell capacitance and its relation with cell death processes. With this objective, the state of the tissue models has been monitored based on the ability of the lipid membranes to accumulate electric charge after the passage of an alternating current of defined frequency, since the integrity of the lipid membranes of the cells has a direct impact on cell viability. For this purpose, capacitance in reconstructed human corneal epithelium tissue models has been evaluated after administration of increasing concentrations of an irritant compound, sodium dodecyl sulfate (SDS). After a period of topical exposure, cell viability was evaluated in terms of capacitance, and the results obtained were compared with a colorimetric assay widely used to evaluate cellular metabolic activity, the MTT assay.
A linear adjustment is observed in both methodologies, obtaining a linear regression for the viability values obtained by the MTT colorimetric test (R2 = 0.90) and for the capacitance values with respect to the SDS concentration (R2 = 0.99) at frequencies equal or greater than 3 kHz. Therefore, capacitance measurements have proven to be a good alternative for the study of cell viability, showing similar results to those obtained with the MTT assay, maintaining the integrity of the sample and being able to increase the number of studies performed on it. In addition, the monitoring of the evolution of cellular activity can be performed in an easy and faster way than the MTT assay, providing comparable results with the advantage of being able to continue using the measured sample.
This work was supported by the Project "NANOBIO-TEER" (IDE/2018/000485 and IDE/2018/000415), co-financed through IDEPA and ERDF fund.
(Invited) Electrochemical Evaluation of Bacterial Activity
Authors: Tanabe So , Sun Shuyi , Itagaki Satohiro , Urai Kazuki , Shiigi Hiroshi 
Published: December 2020

A better understanding of the biological functions of microorganism is required to reduce their threats and increase their usefulness. Therefore, an importance of real-time evaluation of bacterial activity increase for various purposes such as hygiene management, development of antibacterial agents, and effective utilization of bacterial resources.1 This necessitates a quantitative assessment of metabolic processes, including growth and respiration. Here we would like to introduce the development of electrochemical methods for assessing bacterial activity.
Electrochemical detection of viable bacterial cells was performed using cell membrane permeable electron mediator and redox active pigment. Shewanella oneidensis MR-1 transfers electrons generated within the cell to the extracellular environment via the cytochrome complex in the inner/outer membranes and is one of the most useful bacteria for the recovery of metals, treatment of wastewater, and preparation of microbial fuel cells. By using potentiometric measurements, we have examined intracellular electron generation in bacterial suspensions of S. oneidensis supplemented with different carbon sources or ferricyanide, which was almost completely reduced to ferrocyanide during the incubation without affecting bacterial cell viability.2 On the other hand, a tetrazolium salt (MTT), which was converted to an insoluble reduction form (formazan) through the respiration of microbial cells.3 The insolubility of this formazan was effectively exploited as a surface-confined redox event. The electrochemical detection of formazan was effectively coupled with the thermal lysis of microbes. The sensitivity of the present technique is up to 10,000-fold higher than that of MTT colorimetry and requires an incubation time of only 1 h, which is approximately 1/4 of that required for other metabolism-based techniques. Furthermore, the measurement of the reduction current of dissolved oxygen provides an effective mean for assessing the respiratory activity of bacteria in suspension.4

1) T. Kinoshita, K. Ishiki, D. Q. Nguyen, H. Shiigi, T. Nagaoka, Anal. Chem., 90(6), 4098 (2018).
2) K. Ishiki, H. Shiigi, Anal. Chem., 91(22), 14401-14406 (2019).
3) K. Ishiki, D. Q. Nguyen, A. Morishita, H. Shiigi, T. Nagaoka, Anal. Chem., 90(18), 10903 (2018).
4) M. Saito, K. Ishiki, D. Q. Nguyen, H. Shiigi, Anal. Chem., 91(20), 12793-12798 (2019).
Polysaccharide-Based Self-Healing Polymer Binder Using Schiff Base Chemistry for High Performance Silicon Anodes in Lithium Ion Batteries
Authors: K K Rajeev , Kim Tae-Hyun 
Published: December 2020

Lithium-ion batteries (LIBs) have become the most attractive energy storage system that enables a wide range of applications such as portable electronic devices and electric vehicles. The development of new generation of electrode materials with high energy density, long cycle life, and power capability has gained much attention nowadays. Silicon is considered as the most promising anode materials for LIBs due to its high theoretical capacity, low working potential, high abundance, and low cost. However, silicon suffers from serious volume changes during the lithiation/delithiation process, which gradually cause the pulverization of the electrode structure and finally fade the capacity. Polymeric binders with high mechanical properties can play a significant role in maintaining electrode structure from the volume expansion stress to achieve long term cycling capacity of the LIBs.
We herein introduce an in situ cross-linked self-healable natural polymer binder for Si anodes using oxidized alginate (OSA) as a cross-linker that contain aldehyde groups, which form covalent bonds with the amino groups of glycol chitosan (GCS) via Schiff base reaction in a reversible manner. The self-healing property and 3-D cross-linked structure of GCS-OSA binders provide multi-point interaction with the SiNPs surface, which provides stronger adhesion strength and higher mechanical robustness. Furthermore, the 3-D network structure and self-healing ability of GCS-OSA, which can accommodate the large volume change of silicon particles during the lithiation/delithiation process and hence maintain the electrode integrity of the anode. As a result, the silicon anode with GCS-OSA binder exhibits enhanced cycling performance and superior rate performance.
3-D Edge-Oriented Electrocatalytic NiCo2S4 nanoflakes on Vertical Graphene for Lithium Sulfur Batteries
Authors: Li Wenyue , Fan Zhaoyang 
Published: December 2020

Polysulfide shuttling between the sulfur cathode and the lithium anode leads to low Columbic efficiency and cycling stability, which hinders the development of practical lithium sulfur batteries (LSBs). Introducing catalytic nanostructures to stabilize the otherwise soluble polysulfides and promote their conversion to solids has been proved to be an effective strategy in addressing this problem, but the heavy mass of catalysts often results in a low specific energy of the whole electrode.
In this work, nickel cobalt sulfide (NiCo2S4, NCS), one of the promising catalytic materials, was investigated to enhance the LSB performance by grafting it to vertical graphene (VG) grown on carbon nanofiber film(CNF) substrate. Different from previous studies, here NCS nanosheets possess ultrathin and edge-oriented structure, inherited from the underlying VG. As a result, this NCS/VG material not only significantly reduces the needed mass of NCS catalyst but also enormously improves the conductivity of the hybrid structure. When using this free-standing film as catalytic overlayer on top of the sulfur cathode, the polysulfide shuttle effect is largely alleviated, as revealed by the enhanced electrochemical performance and the catalytic function demonstration. The assembled LSB exhibited attractive electrochemical performances of 1000 mAh g-1 specific capacity at 0.3C and 800 mAh g-1 at 1C within 400 cycles for 2 mg cm-2of sulfur loading and 850 mAh g-1 specific capacity at 0.25C for 6 mg cm-2 of sulfur loading. An areal capacity of 4.5 mAh cm-2 was demonstrated at the 100th cycle at 0.3 C.
Local Interactions Governing the Performances of Lithium and Manganese-Richcathodes
Authors: Simonelli Laura 
Published: December 2020

Li-rich layered transition metal oxides Li[Li0.2Ni0.16Mn0.56Co0.08]O2 are attractive electrode materials providing high energy densities, relatively good cycling stability with reduced environmental costs [1]. However, their utility in many applications suffers from both voltage and capacity fade, most likely related to structural transformations and not yet fully understood [2].
We investigated the manganese oxidation and spin states which are linked to the Mn size and magnetic interactions, resulting key parameters in defining the possible phases in which this cation may be involved [1, 3], and then in controlling the reversibility of the reactions along cycling. The Mn redox-state, constantly in opposition to the expected charge compensation, and spin-state resulted correlated with Ni oxidation/reduction, also spatially, suggesting that strain induced on the Mn−O sublattice by Ni oxidation triggers Mn reduction [3].
To elaborate design strategies that can be used to control the structure, for instance, hindering the spinel formation at the benefit of the electrode cycle life, it results then fundamental to address quantitatively how the strain controls the Mn oxidation and spin state.
Here we report about the local structural and electronical transformations during electrochemical cycling of a Li[Li0.2Ni0.16Mn0.56Co0.08]O2 cathode, combining several complementary techniques: X-ray absorption (Mn, Ni, and O K-edge) and X-ray emission spectroscopy (Mn Kβ emission line).
We focus mainly on the first charge and discharge cycle, identifying few key states of charge: the pristine state, the beginning and the end of the high voltage plateau, and the fully charged and following discharged states. The partially irreversible spinel formation, occurring at the expenses of the cycling layered phase, is quantified. Moreover, the local strains induced by the Ni oxidation have been characterized. Finally, the quantification of the different Mn electronic phases present at the different charge states along the first cycle permits to determine the charge redistribution among all elements of the cathode material.
The reported results unravel the role of strains in controlling the electrochemistry of Li-rich cathodes.
[1] Rozier, P.; Tarascon, J. M. Li-Rich Layered Oxide Cathodes for
Next-Generation Li-Ion Batteries: Chances and Challenges. J. Electrochem.
Soc. 2015, 162 (14), A2490.
[2] D. Mohanty et al. J. of Power Sources
229 (2013), 239
[3] L. Simonelli et al. J. Phys.
Chem.
Lett. 10, (2019), 3359
Corresponding author: lsimonelli@cells.es
Towards Stable Water-in-Salt Electrolytes for Sodium-Ion Batteries
Authors: Kuehnel Ruben-Simon , Reber David , Becker Maximilian , Battaglia Corsin 
Published: December 2020

Water-in-salt electrolytes have enabled the development of novel high-voltage aqueous lithium-ion batteries due to their high electrochemical stability compared to traditional aqueous electrolytes.[1, 2] The development of equivalent sodium electrolytes is hindered by two factors:

Low solubility of suitable sodium salts. For example, NaTFSI has a solubility at room temperature of only 8 mol/kg compared to 21 mol/kg for LiTFSI.[3]

A higher salt concentration is needed to reach the same level of electrochemical stability due to the lower charge density of Na+ compared to Li+.[4]

In this study, we screen >100 combinations of up to five sodium salts with water to identify highly concentrated solutions that are thermodynamically in the liquid state at ≤25 °C.[5, 6] An additional criterion for a stable water-in-salt electrolyte is a high content of SEI-forming anions. Furthermore, we find that the electrochemical stability of the electrolyte benefits from anions that are only weakly coordinating. In fact, we discovered a strong correlation between the stability of the electrolyte and the position of the anion in the Hofmeister series.[6]
Our findings led to the development of multiple 2 V-class sodium-ion batteries with Coulombic efficiencies of up to 99.8% during cycling at a rate of 1C and record-high energy densities for such devices of up to 77 Wh/kg based on the active masses of both anode and cathode.[6]
[1] L. Suo, O. Borodin, T. Gao, M. Olguin, J. Ho, X. Fan, C. Luo, C. Wang, K. Xu, Science 350 (2015) 938–943.
[2] Y. Yamada, K. Usui, K. Sodeyama, S. Ko, Y. Tateyama, A. Yamada, Nat. Energy 1 (2016) 16129.
[3] R.-S. Kühnel, D. Reber, C. Battaglia, ACS Energy Lett. 2 (2017) 2005–2006.
[4] D. Reber, R. Figi, R.-S. Kühnel, C. Battaglia, Electrochim. Acta 321 (2019) 134644.
[5] D. Reber, R.-S. Kühnel, C. Battaglia, ACS Mater. Lett. 1 (2019) 44–51.
[6] D. Reber, M. Becker, R.-S. Kühnel, C. Battaglia, submitted.
Ion-Conductive Self-Healing Polymer Network Based on Reversible Imine Bonding for Si Electrodes
Authors: Nam Jaebin , Kim Tae-Hyun 
Published: December 2020

Lithium-ion battery (LIB), one of the most promising energy storage devices due to higher energy density than other secondary batteries, have continuously developed, and their market has been growing steadily. Currently, the efforts have been produced for using LIB in electric vehicles (EVs) and energy storage systems (ESS) storage beyond small portable devices. Higher energy density and faster charge/discharge rate are required for the practical application of LIB to these large-scale energy devices, and new materials to meet these requirements are hence necessary. Silicon has been reported as an anode material for the next-generation LIB due to its outstanding theoretical capacity and natural abundance. However, there are many limitations in practical application due to the continuous deterioration of the battery performances by enormous volume change of this active material. These problems are mainly originated from the structural deterioration of the electrode causing loss of conductive pathway and the active area for the electrode. Hence, many approaches to securing the structural stability of the Si electrode through various methods, including polymeric binders with good adhesion with Si were developed.
In this study, self-healable polymeric binder was designed through a crosslinking polymer network using a reversible imine chemistry. Additionally, the ion conductive polymer was introduced to improve ion conductivities of this self-healable binder. The synthesis, characterization and the electrical properties of the proposed polymeric binder for high-performance silicon electrodes will be discussed in detail.
Interfaces and Electrolyte Additives for Long-Life Sodium-Ion and Lithium-Ion Batteries
Authors: Chen Lin , Kishore Brij , Dancer Claire , Kendrick Emma 
Published: December 2020

Sodium-ion batteries (NIBs) are attracting considerable attention as post lithium-ion batteries (LIBs) as they are a likely ‘drop-in’ technology which can be produced using existing manufacturing lines. One of the processes in manufacturing which is least understood is the formation and conditioning step; both battery technologies require a formation of the surface electrolyte interface (SEI) and cathode electrolyte interface (CEI) for long life cells. Here we discuss the formation, conditioning and electrolyte additives for the creation of the stable interfaces for high cycle life.
In particular we highlight the similarities of the formation step in the manufacturing process for a NIB layered oxide-hard carbon chemistry and LIB NMC-graphite, and the subsequent differences in the SEI observed1. Methods for faster formation protocols for NIB and LIB where targeted voltage windows in active formation methods produce more stable interfaces are introduced2,3 and we show the effect upon the composition of the SEI layer using these different protocols.
In all cases full cells were made with in a coin-cell figuration, these cells were subjected to different formation protocols and electrolytes additives such as FEC, VC and a new inorganic solid state additive. After formation the impedance of the cells were measured, and then cycled for 500 cycles at a higher rate to accelerate the ageing process. The resistance and the capacity of the cells were monitored during cycling. We show that even in a coin cell configuration significant differences in the cycle life are observed with different formation protocols and electrolyte additives. In addition we show the difference in the stability of the SEI in carbonate-based electrolytes between NIBs and LIBs. The effect upon the stability of the SEI and the performance of a NIB with a sodium metal oxide cathode and a hard carbon anode is discussed in detail and the role of the formation protocols and the inorganic additive. We also suggest the role of the additives for NIB and suggest the mechanism for which the stability is enhanced.

Roberts, S. & Kendrick, E. The re-emergence of sodium ion batteries: testing, processing, and manufacturability. Nanotechnol. Sci. Appl.
Volume 11, 23–33 (2018).

Pathan, T. S., Rashid, M., Walker, M., Widanage, W. D. & Kendrick, E. Active formation of Li-ion batteries and its effect on cycle life. J. Phys. Energy
1, 044003 (2019).

Kendrick, E. Optimisation Of Formation And Cell Ageing Protocols For Lithium Ion EV Batteries. Batter. Supercaps (2020). doi:10.1002/batt.202000048