bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Immuno-Biosensors on Nanostructured Electrodes for Rapid Sensitive Detection of Disease Biomarkers
Authors: Mahshid Sahar Sadat 
Published: July 2021

Development of rapid tests for quantitative detection of analytes in complex matrices, plays an important role in medical diagnostics, prognostics and therapeutics. Current methods for molecular diagnostics are time-consuming and multiple-step reliant on well-trained technicians and fully-equipped laboratories to provide quantitative detection of biomarkers. In this case, the challenges to overcome the sensitivity and selectivity of working directly in biological fluids in a timely manner have always been the main step for the development of such rapid tests.
Electrochemical sensors, analogous to glucometer, are known to be rapid with the ability to provide direct electronic signal without any interference from the biological phenomena. When functionalized with specific biological substances, they intend to provide the required specificity in addition to signal selectivity in biological fluids. Inspired by nature, we design biorecognition probes that are combined with newest advancement in the engineering for the development of electrochemical immune-biosensors. These molecular recognition probes are designed using the ability of antibodies to bind antigens, and DNA construct to hybridize to the complementary construct, to create specificity for direct detection in complex media. On the other hand, we rely on the innovative approaches in nanomaterials, surface sciences, and self-assembly techniques to improve the conductivity and sensitivity of electrode surface. This includes the incorporation of high-curvature nanostructured microelectrodes that helps with the efficiency of molecular interactions at the surface and the transfer of electrons for the ease of signal transduction.
In this regard, we fabricate small-scale nanostructured electrodes and engineer the surface for the immobilization of the biomolecular monolayer at the interface to provide the desired specificity for biomarkers in real biological samples, e.g. whole blood. We adapted our nano-bio-sensors for translational applications such as (1) at-line monitoring of signaling proteins in hematopoietic stem cell expansion, (2) rapid diagnosis of pathogenic infections through quantitative detection of antibodies directly in patient samples, and (3) rapid diagnosis of inner ear disorders based on the detection of blood biomarkers. We showed that our electrochemical immune-biosensors are capable of detecting at therapeutic concentrations with tunable ranges while performing in a 10 µL sample within less than 30 minutes.
Catechol-O-Methyl Transferase (COMT) Activity Detection Using Metal Oxide Electrodes
Authors: Lisdat Fred , Göbel Gero 
Published: July 2021

Parkinson’s disease is one of the most frequent diseases of the central nervous system with rather severe consequences for patients. Since the disorder can not be cured, the dopamine level in the brain needs to adjusted. Here several key enzymes of the dopamine metabolism [e. g. catechol-O-methyl transferase (COMT)] are targets for administered drugs. However, the efficiency of the treatment is decreasing with time. Consequently a monitoring of the actual activity of these enezmyes and an adjustment of the pharmaceutical treatment would be beneficial to prolong the treatment effects.
In this study, an electrochemical approach is introduced for activity determination of the COMT enzyme. As detection method differential pulse voltammetry (DPV) has been used exploiting an improved signal to noise ratio. Activity determination is based on the selective detection of one substance in the reaction scheme of the enzyme – here dopamine. As electrode material fluorine doped tin oxide (FTO) has been elucidated since it is characterized by a clear discrimination between the substrate and the product of the COMT [1]. This can be achieved without additional layers on top of the electrode. The response is characterized by a rather high stability of the dopamine signal during consecutive measurements and a linear dependency of the peak currents on the dopamine concentration in the range of the maximum reaction rate of COMT [2]. Furthermore it has been detected that redox active interferences such as ascorbic acid do not disturb the analysis.
Despite these advantageous results, it has been found that the electrochemical dopamine oxidation in the complete activity assay is influenced by each of the added essential assay components, even though none of the added components reveal a current signal at the FTO electrode itself. After adjusting the potential range of the electrochemical analysis and the solution composition, these effects can be circumvented.
Consequently, by following the dopamine concentrations during COMT action, it can be shown that the
activity of the enzyme can be detected by using DPV at a FTO electrode. Experiments with different amounts of the enzyme further demonstrate that activity quantification is feasible.
References
[1] G. Göbel, A. Talke, F. Lisdat, Electroanalysis, 2018, Vol. 30 (2), p. 225-229
[2] G. Göbel, A. Talke, U. Ahnert, F. Lisdat, ChemElectroChem, 2019, Vol. 6 (17)
Synergistic Effects of Au and SnO2 Nanoparticles Decorated on WS2 Nanosheets for Flexible, Room-Temperature CO Gas Sensing
Authors: Kim Jae-Hun , Kim Sang Sub , Saito Noriko 
Published: July 2021

Two-dimensional (2D) materials such as graphene and graphene oxide are desirable for sensing applications owing to their high surface-to-volume ratio. Recently another class of 2D materials namely transition metal dichalcogenides (TMDs) with semiconducting properties have gained extensive attention for gas sensing studies due to their high surface area and excellent electronic and catalytic properties. TMDs form layered structures, where adjacent layers are held together by weak van der Waals forces. Accordingly, they can be easily exfoliated into individual 2D layers with high surface area which is a merit for sensing applications.
WS2 is a promising 2D TMD for sensing applications thanks to high surface area and excellent electrical properties. However, for sufficient sensing applications its sensitivity needs to be improved more. A good strategy for that purpose is to functionalize with noble metal and metal oxide nanoparticles (NPs). NPs can make additional charge depletion zone in WS2 nanosheets, thereby amplifying their resistance modulation during interaction with gas molecules. Furthermore, NPs can provide a spillover effect; facilitating adsorption, dissociation, and transfer of target gases to WS2 nanosheets surface. This can lead to improved sensitivity towards a specific gas.
In this study, WS2 nanosheets that are bare or decorated with Au, SnO2, or a combination of Au and SnO2 were realized on flexible polyamide substrates. The fabricated sensors were operated for CO gas sensing in applied-voltage-induced self-heating mode at room temperature (24 ºC). Not only optimal applied voltage was varied for the sensing of different gases, but also that the sensors behaved uniquely in response to CO gas. Therefore, the optimized applied voltage for the fabricated sensors and their room temperature sensing characteristics were investigated. Furthermore, we investigated that tilting, bending and stretching conditions to the optimized gas sensor. Also, we suggested that the enhanced response was related to the formation of Au-WS2 and Au-SnO2 Schottky junctions, n-SnO2-n-WS2 heterojunctions, and the catalytic performance of Au NPs towards CO gas. The results obtained in this study provide new avenues towards fabrication of flexible, low power gas sensors using metal chalcogenides.
SO2 Gas Sensor Based on LATP Solid Electrolyte
Authors: Fung Kuan-Zong , Tsai Shu-Yi 
Published: July 2021

The emission of SO2 mainly comes from the burning of fossil fuels such coal and sulfur-containing oil. Thus, the source of SO2 emission may be contributed from power plants or steel making factories.
Exposures to SO2 can harm the human respiratory system and make breathing difficult. People suffered by asthma are sensitive to these effects of SO2. To improve air quality, the concentration of SO2 is typically limited by national and/or regional standards to reduce emissions of SO2. Therefore, the accurate detection of SO2 is important. Electrochemical solid state sensors are known to provide reliable and stable signals based on the use of solid electrolytes. Oxygen sensors based on oxygen-conducting yittria-stabilized zirconia have shown their wide applications. In this study, a solid state SO2 sensor are developed using Li-conducting Li1.3Al0.3Ti1.7(PO4)3 (LATP). Li2SO4 is used as electrode. With the application of adequate voltage, Li2SO4 may be formed at the surface exposed to SO2-containing atmosphere. Thus, the current measured from the sensors is expected to be proportional to the concentration of SO2. The dependence of SO2 concentration, temperature, and electrode microstructure will be analyzed and discussed.
pH Micro-Sensor from IrOx SECM Microelectrode for Local pH Measurement While Chromium Electrodeposition
Authors: Dasque Ariane , Gressier Marie , Taberna Pierre-Louis , Menu Marie-Joelle 
Published: July 2021

In this work, it will be presented the chromium electrodeposition mechanisms with the use of a Scanning ElectroChemical Microscopy (SECM) micro-electrode. Among several factors, the pH is key to achieve even a metallic deposit. pH buffers and complexing agents are often used for this purpose [1] but in the vicinity of the electrode, at the electrode/electrolyte interface, strong variations are highly likely to occur. To this respect, since pH is a key parameter, a pH micro-electrode is intended to be developed to scan the pH gradient upon the electrodeposition of chromium. The first part of this work is so devoted to the pH micro-electrode realization from microelectrode on which iridium oxide is deposited. Iridium oxide has been reported to be suitable for local pH sensing [2-4]. Different parameters have been studied such as IrOx thickness and thermal treatment. The addition of Nafion has been assessed as well to achieve a tradeoff between fast response time, good selectivity and good stability [5]. An optimized IrOx micro-electrode has been obtained and used as SECM micro-electrode to get the evolution of the pH at the electrode/electrolyte interface upon electrodeposition. Different micro-electrode diameters have been used to improve the resolution. These results are promising and will allow going further to the development of chromium electrodeposition electrolyte helping to select the different complexing agents.
[1] D. Del Pianta et al. Determination of the chromium(III) reduction mechanism during chromium electroplating. Electrochimica Acta (2018) 234-241.
[2] H. A. Elsen et al. Effects of electrodeposition conditions and protocol on the properties of iridium oxide pH sensors electrodes. J. Electrochem Soc. 156 (2009).
[3] C. S. Santos et al. Fabrication and use od dual-function iridium oxide coated gold SECM tips. An application to pH monitoring above copper electrode surface during nitrate reduction. Electroanalysis 28 (2016) 1441-1447.
[4] Z. Zhu et al. A fabrication of iridium oxide film pH micro-sensor on Pt ultramicroelectrode and its application on in-situ pH distribution of 316 stainless steel corrosion at open circuit potential. Sensors and Actuators B 25 (2018) 1974-1982.
Electrochemical Detection of Biomolecules for Agriculture and Farming Applications
Authors: Durairaj Sharmila , Chen Aicheng 
Published: July 2021

There is an increasing interest in developing efficient techniques to detect agri-based biomolecules and biomarkers to improve food production and quality. Electrochemical sensors and biosensors are desirable over conventional analytical techniques due to the advantages of instrumental simplicity, rapid response, high sensitivity, cost-effectiveness, and portability [1-4]. The development of nanomaterials has paved the way for their applicability in designing high-performance electrochemical sensing devices for agriculture and environmental applications. Hydroxyproline (Hyp) is a significant amino acid present in connective tissues and extracellular matrix in all animal cells. Hyp's quantitative analysis plays a vital role in the quality testing of chicken, swine, and beef meat in farming. In the animal farming industry, sodium metabisulfite (SMBS) is used as a feed additive to control the effect of deoxynivalenol (DON), a mycotoxin from Fusarium Species. The monitoring of SMBS is essential as its over-dosage may cause significant side effects like stomach upset or heaviness. In this presentation, the synthesis of gold nanoparticles and graphene-based nanocomposites, and their applications for the detection of Hyp and SMBS are highlighted. Our study has shown that gold nanoparticles exhibit high sensitivity (8.5 μA/μM cm-2), a low limit of detection (2.6 μM), and a wide linear range for the detection of Hyp. The fabricated gold and fluorine-doped reduced graphene oxide nanocomposites show high-performance for detecting SMBS in different digestive fluids such as stimulated salivary fluid and simulated gastric fluid. The roles of nanomaterials in the electrochemical sensing applications are also discussed.
[1] V.S. Manikandan, B.R. Adhikari, A. Chen, Analyst,
143, 4537-4554 (2018).
[2] Z. Liu, V.S. Manikandan, A. Chen,Curr. Opin. Electrochem., 16, 127-133 (2019).
[3] S. Durairaj, B. Sidhureddy, A. Chen, J. Electrochem. Soc.,
167, 167511 (2020).
[4] J. van der Zalm, S. Chen, W. Huang, A. Chen, J. Electrochem. Soc.,
167
, 037532 (2020).
(IMCS Second Place Best Paper Winner) Investigation of Room Temperature Ionic-Liquid (RTIL) Modified Electrode for Decoupling Soil Electrochemistry
Authors: Dhamu Vikram Narayanan , Paul Anirban , Muthukumar Sriram , Prasad Shalini 
Published: July 2021

Room temperature ionic liquid (RTIL) is a unique zwitter-ionic compound, that possesses excellent physical and chemical properties, which enables electrochemical applications such as to be utilized as a transducer for probing a complex matrix such as soil. The wide electrochemical window and elevated double layer capacitance of RTIL helps to gauge soil parameters which is helpful to understand soil state. In this work we investigate the utility of RTIL modified electrodes as viable sensors for decoupling soil electrochemistry. Soil plays the key role in plant and crop production and is a vital parameter in the ecological structure of the planet and indispensable in the food ecosystem cycle. Soil health monitoring in the near past has been highly qualitative and speculative with more recent advancements still trying to fill the void of a holistic soil profile. In fields and crop-circles, testing methods to perform in-situ profiling however from one lab is likely to vary with another and hence results are not universally compatible. Additionally, these normalized techniques ideally involve empirical approaches, extensive sample preparation which adds on to a temporal factor along with equipment for extraction and subsequently-analysis. This therefore-stimulates the need for a testing methodology that is capable of rapid analysis in an in-situ environment that can be applicable universally.
In this paper, we focus on: a rapid electrochemical point probing mechanism that acts as a soil state evaluation platform via a 3-electrode sensor modified by a widely characterized-RTIL [BMIM] [BF4] interfacial transducer medium. The proposed quantitative model –‘DENSE’ probes the soil diffuse double layer (DDL) dielectric to evaluate a thorough chemical profile of the soil matrix. The experimental design was implemented to capture the effect of electroactive species in the soil matrix altered by adding nutritional amendments. Non-faradaic probing was then performed in this design to gauge the inherent capacitive modulations of the soil system as a function its compositional changes. Therefore, by looking at the rate of electrochemical activity and inherent soil dielectric changes driven by an RTIL interfacial layer, it is possible to decouple information on nutrient availability in soils with potential for application towards temporal soil analysis.
Figure: (A) Equivalent-circuit (DENSE) model of the soil-water matrix and a schematic representation of the model with respect to the electrode-electrolyte interface (B) Impedance nyquist plot and (C) Bode-phase to denote the pseudo-capacitive dominant nature of the soil matrix (1:1, 1:2) and the comparatively resistive behavior of the baseline and 2:1 mixture

Figure 1
(Invited) 4D Printed Soft-Matter Robotics: Materials, Fabrication and Applications
Authors: Furukawa Hidemitsu , Khosla Ajit 
Published: July 2021

Soft robotics is a relatively new and rapidly emerging field of research that encompasses development of soft functional materials i.e. soft matter, fabrication techniques, and artificial intelligence. 3D printing facilitates fabrication of complex shapes and structures, placement of multiple soft matter, and customization of soft robots which is not possible conventional subtractive manufacturing technologies. 4D printing relates to the evolution in the shape, property, and functionality of a 3D printed structure with time when exposed to the stimuli. 4D printing can replicate natural physio-mechanical changes over time leading the transition from static to dynamic.
This talk will focus on 4D printed soft robotics by employing various types gel materials [1], fabrication of embedded gel sensors (physical and chemical) [2], actuation methodologies and sensing mechanisms [3], development of custom build 3D printer for gel materials [4], applications and examples of prototypes leading towards commercialization [5].
References:

Kumkum Ahmed, MD Nahin Islam Shiblee, Ajit Khosla, Larry Aiko Nagahara, Thomas Thundat, Hidemitsu Furukawa (2020) “Recent Progresses in 4D Printing of Gel Materials- A Review.” J. Electrochem. Soc. 167 037563. https://doi.org/10.1149/1945-7111/ab6e60

Hara, Yuta, Kazunari Yoshida, Ajit Khosla, Masaru Kawakami, Koh Hosoda, and Hidemitsu Furukawa. "Very Wide Sensing Range and Hysteresis Behaviors of Tactile Sensor Developed by Embedding Soft Ionic Gels in Soft Silicone Elastomers." ECS Journal of Solid State Science and Technology9, no. 6 (2020): 061024. https://doi.org/10.1149/2162-8777/aba913

MD Nahin Islam Shiblee, Kumkum Ahmed, Ajit Khosla, Masaru Kawakami, and Hidemitsu Furukawa (2018). "3D Printing of Shape Memory Hydrogels with Tunable Mechanical Properties." Soft matter, 2018,14, 7809-7817. https://doi.org/10.1039/C8SM01156G

Yosuke Sato, Azusa Saito, Yosuke Watanabe, MD Nahin Islam Shiblee, Jun Ogawa, Ajit Khosla, Masaru Kawakami, and Hidemitsu Furukawa. "Material Development and Equipment Improvement for 3D Gel Printing Using a Commercially-Available Stereolithography Printer." ECS Transactions98, no. 13 (2020): 93. https://doi.org/10.1149/09813.0093ecst

Jun Ogawa, Naoya Yamada, Yosuke Watanabe, Ajit Khosla, Masaru Kawakami, and Hidemitsu Furukawa. "Design of Hydrogel Material and 3D-Printed Molding for Imitating the Tactile Textured Properties of Moon Jellyfish." ECS Transactions 98, no. 13 (2020): 39. https://doi.org/10.1149/09813.0039ecst
Micromechanical Resonators for Ultrasound-Based Sensors
Authors: Farhoudi Navid , Laurentius Lars B , Magda Jules , Reiche Christopher F , Solzbacher Florian 
Published: July 2021

The current field of biomedical sensor platforms is substantial, and ever more creative approaches are envisioned and realized. Herein, we showcase a new platform technology for continuous biomedical analyte sensing that relies on the resonance absorption of ultrasound waves in microfabricated smart hydrogel structures (see Figure 1). Smart hydrogels can be tailored to be biocompatible and respond to many different analytes to undergo a volume-phase transition in response to changing levels of these biomarkers. [1,2] In addition, smart hydrogels can be designed to be biodegradable by basing them on compositions that include poly(ethylene glycol), poly(methyl methacrylate), or hyaluronic acid.
Employing smart hydrogel structures as mechanical resonators and probing them using ultrasound [3,4] can provide an implantable sensor platform that is minimally invasive and free of transcutaneous wires. This approach makes use of the fact that hydrogel structures exhibit a resonant oscillation at certain ultrasound frequencies by strongly absorbing mechanical energy. As they swell or contract in response to the presence or absence of the target analyte, their resonance frequencies change, leading to a modification of their ultrasound absorption spectrum. Measuring this allows for the reconstruction of analyte concentration changes. In addition to that, tailoring the resonance frequency of the hydrogel resonator structures to different frequency ranges allows for multiplexing. We successfully demonstrate the use of this platform technology using glucose as a target metabolic marker in vitro and in a rat model (see Figure 2).
Florian Solzbacher declares financial interest in Blackrock Microsystems LLC and Sentiomed, Inc. Jules Magda declares financial interest in Applied Biosensors LLC.
[1] Buenger, F. Topuz, and J. Groll, “Hydrogels in sensing applications,” Prog. Polym. Sci., vol. 37, no. 12, pp. 1678–1719, 2012.
[2] A. Peppas, J. Z. Hilt, A. Khademhosseini, and R. Langer, “Hydrogels in biology and medicine: From molecular principles to bionanotechnology,” Adv. Mater., vol. 18, no. 11, pp. 1345–1360, Jun. 2006.
[3] Carovac, F. Smajlovic, and D. Junuzovic, “Application of Ultrasound in Medicine,” Acta Inform. Medica, vol. 19, no. 3, p. 168, 2011.
[4] Troïani, J. R. Dion, and D. H. Burns, “Ultrasonic quantification using smart hydrogel sensors,” Talanta, vol. 83, no. 5, pp. 1371–1375, 2011.

Figure 1