bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Digital Presentation) Improved Densification of Proton Conducting BaCe0.5Zr0.3Y0.2O3-δ by Impurity Addition
Authors: Fung Kuan-Zong , Tsai Yuan Jie , Tsai Shu-Yi 
Published: July 2022

BaCe0.5Zr0.3Y0.2O3-δ (BCZY) electrolyte is known to be a high proton conducting electrolyte for proton-solid oxide electrolyzer cell (P-SOEC) applications. There are some advantages such as (1) Reduce Cr evaporation and mitigate materials degradation, (2)Use of lower cost metals, alloys and coatings, (3) Ease of gas sealing, (4) Reduced cost of hydrogen production by using proton conducting electrolyte. To become a desired solid electrolyte with >95% relative density, a typical BCZY electrolyte needs to be sintered at temperatures greater than 1400°C. A better sintering approach was developed in this study.
With slight modification on sintering conditions, dense BaCe0.5Zr0.3Y0.2O3-δ electrolyte was obtained at a temperature as low as 1200°C. Without any modification, BCZY reached 90% relative density only when sintered at 1250°C. With proper impurity addition, BCZY may reach 97% relative density under the same conditions. From analysis, it is suggested that the densification of BCZY is promoted due to impurity induced liquid-phase sintering mechanism. In addition, the conductivity of highly densified BCZY reached 5.86×10-3 S/cm at 700°C. The crystal structure and microstructure of sintered BCZY was also characterized using XRD and field-emission SEM.
Organic Electrochemistry and the Use of Microelectrode Arrays to Probe Small-Molecule Protein Interactions
Authors: Moeller Kevin D , White-Drayton Kendra , Liu Siyue , Chang Yu-Chia 
Published: July 2022

While electrochemical methods offer many unique opportunities for synthesis,1 the relationship does work in both directions. As part of an effort to develop microelectrode arrays as tools for monitoring small molecule – receptor interactions in real time, but have been working to show how synthetic chemistry can be used in order to build two-dimensional addressable surfaces on an array. The reactions themselves work nicely. But the overall strategy that has as its focus the construction of addressable molecular libraries that can be used to guide synthetic efforts brings with it not only synthetic challenges, but analytical ones as well. Many of the common direct detection methods used on microelectrode arrays and other electrochemical sensors are not compatible with a polymer coated electrode surface that has a lifetime consistent with using electrochemistry interactively with a synthetic endeavor. The surfaces required are thicker and more robust than typical SAMs that need to survive for months and be stable to a myriad of synthetic efforts.
The result is a need to develop indirect methods for detecting binding events on the arrays. These methods are modeled after electrochemical impedance experiments and take advantage of redox mediators in the solution above the array. A current is established for the mediator at each electrode in the array and then that current used to monitor binding events between molecules on the surface of the electrodes and biological targets in solution. In the talk to be presented, a quick review of how the surface used, how those surfaces can be functionalized, and how molecules on an array can be characterized will be presented along with a guide for how to conduct the analytical experiments used, how those methods can be calibrated, the problems that can arise, and how those problems can be recognized and addressed.
References:
Graaf, M. D.; Moeller, K. D. Langmuir, 2015, 31, 7697-7706.
Graaf, M. D.; Marquez, B. V.; Yeh, N. H.; Lapi, S. E.; Moeller, K. D. ACS Chem. Bio.
2016, 11, 2829-2837.
Yeh, N. H.; Zhu, Y.; Moeller, K. D. ChemElectroChem
2019, 6, 4134-4143.
Krueger, R.; Moeller, K. D. J. Org. Chem.
2021, 86, 15487-15865.
Electrochemical Monitoring of the Superoxide Anion Radical with Quercetin and Metallo-Quercetin Complexes
Authors: Lewis Tyra , Martic Sanela 
Published: July 2022

Excess production of reactive oxygen species (ROS), such as the superoxide anion radical (O2˙–) can contribute to oxidative stress, and subsequently the onset of some pathological diseases. The free radical, O2˙–, is naturally generated in the body via a single electron reduction of molecular oxygen.1-3 Phenolic compounds such as flavonoids have strong antioxidant properties against ROS, including O2˙–.1,3 Due to their ability to donate an electron to the ROS, antioxidants actively act as free radical scavengers, which allows for prevention of cell damage and related health issues induced by ROS production.1 In addition to antioxidant properties, flavonoids such as quercetin (QCR) also play a role as metal ion chelators, by which their coordination with biologically relevant metal ions results in the formation of metallo-flavonoid complexes.2 Metal ions are known to regulate ROS activity via Fenton reactions, which may also influence the antioxidant activity and capacity of the flavonoid upon complexation. The role of metal ions and metallo-flavonoid complexes as antioxidants towards O2˙– is not fully understood. Herein, cyclic voltammetry (CV) was employed for electrochemical generation of the O2˙–/O2 redox couple.4 The anodic and cathodic peaks associated with the redox couple were monitored prior and post interaction with QCR and its metallo-QCR complexes. Overall, CV data show a decrease in anodic and cathodic peak currents, demonstrating varying extents of antioxidant activity and O2 reactivity with the antioxidants.

References

[1] N. L. Zabik, S. Anwar, I Ziu, S. Martic-Milne, Electrochim. Acta,
296, 174-180 (2019).
[2] M. M. Kasprzak, A. Erxleben, J. Ochocki, RSC Adv.,
5, 45853-45877 (2015).
[3] S. Ahmed, F. Shakeel, Czech J. Food Sci.,
30, 153-163 (2012).
[4] T. Lewis, W. Wallace, F. Dingman Peterson, S. Rafferty, S. Martic, Electrochem. Sci. Adv., e2100054 (2021).
(Digital Presentation) Selective Electrochemical Fluorination of Dithioacetals and O,S-Acetals Bearing α-Electron-Withdrawing Groups
Authors: Fuchigami Toshio , Yin Bin , Inagi Shinsuke 
Published: July 2022

Organic electrosynthesis is expected to be a typical green chemical process.1 On the other hand, organofluorine compounds are key materials applied in daily life because of their versatile utility as functional materials, pharmaceuticals, and agrochemicals. Although organic electrosynthesis has a long history2, electrosynthesis of organofluorine compounds has been unexplored until ca. 30 years ago. With these facts in mind, we have developed electrochemical systems for selective fluorination of organic compounds including macromolecules and molecular conversion of organofluorine compound.3-7

In this talk, we will describe selective anodic fluorination and fluoro-desulfurization of dithioacetals and O,S-acetals having α-electron-withdrawing groups using various poly(HF) salts and solvents. It was found that oxidative elimination of α-proton followed by fluorination and fluorodesulfurization were greatly affected by EWG and/or electrolytic conditions.8,9

References
1) Fuchigami, M. Atobe, S. Inagi, Fundamentals and Applications of Organic Electrochemistry:
Synthesis, Materials, Devices, Wiley, 2014.
2) Fuchigami, Chem. Rec.,
21
, 2079 (2021).
3) Fuchigami, S. Inagi, Acc. Chem. Res.,
53
, 322 (2020).
4) Inagi, T. Fuchigami, Chem. Commun. (Feature Article),
47
, 10211 (2011).
5) Oyanagi, H. Ishii, S. Inagi, T. Fuchigami, J. Electrochem. Soc.
167 155511 (2020).
6) Ito, K. Kondo, H. Ishii, S. Inagi, T. Fuchigami, J. Electrochem. Soc., 168, 065502 (2021).
7) Shida, T. Fuchigami, S. Inagi et al., J. Org. Chem., 86, 16128 (2021).
8) Yin, S. Inagi, T. Fuchigami, Beilstein J. Org. Chem.
,

11

, 85 (2015).
9) Yin, S. Inagi, T. Fuchigami, Electrochem. Sci. Adv., in press.
(Digital Presentation) Electrochemical Dehydrogenative C–P Bond Formation for the Synthesis of Phosphacycles Using DABCO As a Mediator
Authors: Mitsudo Koichi , Kurimoto Yuji , Yamashita Jun , Suga Seiji 
Published: July 2022

Phosphole oxide-containing π-conjugated molecules have been attracting attention due to their electron acceptability and thermal and chemical stability, and have been used as an important motif for organic functional materials. Among them, diarylphosphole oxide (DPO) is a key motif in the design of phosphole-containing organic functional materials. Recently, intramolecular cyclization of biarylphosphine oxides (BPOs) has received attention as a straightforward way leading to DPOs. BPOs are readily available and easy to handle starting substrates. Although several efficient methods have been reported for synthesizing DPOs with this protocol, these methods require transition metal catalysts, strong acids or excess amounts of acid. Therefore, the development of a transition metal-free and environmentally benign synthetic methodology for synthesizing DPOs is highly desirable.
To overcome the situation, we developed the first electrochemical synthesis of DPOs from BPOs via a dehydrogenative C–P bond formation. The protocol does not use a transition metal mediator and instead uses readily available and inexpensive DABCO as an organic hydrogen atom transfer (HAT) mediator. In the presence of DABCO, the desired C–P bond formation proceeded smoothly and a wide variety of DPOs could be obtained. This method can also be applied to the synthesis of six-membered phosphacycles. Several control experiments were carried out, and the results suggest that a phosphinyl radical was generated in situ and the reaction would proceed via a radical pathway.

Figure 1
(Digital Presentation) Synthesis of Ureas and Carbamates from Carbon Tetrahalides By B12-TiO2 Catalyst Modified with Magnesium Ion
Authors: Tanaka Miho , Shichijo Keita , Shimakoshi Hisashi 
Published: July 2022

Organometallic B12 compounds are unique metal complexes having a cobalt-carbon s-bond present in biological systems. Cleavage of the metal-organic σ-bond initiates many B12 dependent enzymatic reactions. Based on unique properties of B12 enzymes, many B12-inspired reactions were developed.1-3 Here we report the visible light-driven B12inspired reaction for the synthesis of base chemicals from carbon tetrahalides as C1 building block. The hybrid catalyst, B12-Mg2+-TiO2, composed of the B12 derivative and titanium oxide modified with magnesium ion (Mg2+-TiO2) was synthesized for the visible light-driven catalytic reaction (Figure 1). Carbon tetrachloride (CCl4) was converted to N,N-diethylurea by the B12-Mg2+-TiO2 catalyst under the visible light irradiation (l>420 nm) with diethylamine (Et2NH) in air at room temperature. Valuable ureas are synthesized from CCl4 under mild condition. This photochemical catalytic reaction was applied to the synthesis of asymmetric ureas, carbamates, and carbonate ester via carbamoyl chloride in the presence of corresponding nucleophiles, RNH2, R2NH, ROH. Furthermore, the reactions were applied to carbon tetrabromide (CBr4) as substrate. Carbon tetrabromide is a commercially available solid compound which is stable at room temperature and can be easily handled. Scope of substrate and detailed reaction mechanism will be reported in this presentation.
References
[1] H. Shimakoshi, Y. Hisaeda, Chem. Rec., 2021, 21, 2080.
[2] Z. Luo, H. Shimakoshi et al, J. Org. Chem., 2021, 86, 5983.
[3] K. Shichijo, M. Fujitsuka, Y. Hisaeda, H. Shimakoshi, J. Organomet. Chem., 2020, 907, 121058.

Figure 1
Electrochemical Detection of Carboplatin-Resistance in Ovarian Cancer
Authors: Luu Huy Tran Le , Nachtigal Mark W. , Kuss Sabine 
Published: July 2022

Epithelial ovarian cancer (EOC) has the highest mortality rate among gynecological cancers and affects patients on all continents. Primary treatments involve surgery and the administration of chemotherapeutics, such as carboplatin, which is listed by the World Health Organization as an essential medication for the treatment of human cancers. Unfortunately, due to high rates of drug resistance of EOC towards carboplatin, cancer relapse rates are devastating, and the mechanisms of chemoresistance to carboplatin have not been adequately identified. Consequently, there is a dire need for innovative strategies that are able to detect carboplatin resistance in cancer and to further our understanding of the fundamental nature of chemoresistance towards carboplatin.
The presented work describes the thorough electrochemical characterization of carboplatin. The uptake of carboplatin by ovarian cancer cells was quantified by electrochemistry to better understand mechanisms of carboplatin chemoresistance. Scanning Electrochemical Microscopy studies demonstrate a differential behavior between drug-susceptible and drug-resistant ovarian cancer cells, in response to carboplatin exposure. Results emerging from this research might be important for future medical research, developing diagnostic and treatment strategies to combat chemoresistance.
Intact Photosynthetic Bacteria-Based Electrochemical Biosensors
Authors: Grattieri Matteo , Gubitosa Jennifer , Rizzi Vito , Buscemi Gabriella , Stufano Paolo , Agostiano Angela , Trotta Massimo , Cosma Pinalysa , Farinola Gianluca M 
Published: July 2022

Utilizing photosynthetic entities in electrochemical systems enables converting solar energy into electrical energy, obtaining bio-hybrid photo-electrochemical systems. Such systems have been recently proposed for micro power generation, bioelectrosynthesis, and biosensing for in-situ water quality monitoring.[1] However, due to the photosynthetic apparatus in bacteria (i.e., purple bacteria and cyanobacteria) being physically separated from the electrode surface by the presence of various membrane layers, artificial approaches to divert the photoexcited electrons are required. As a result, research efforts have been focused on developing bio-compatible approaches to facilitate the transfer of photoexcited electrons from these bacteria to the electrodes (and vice versa).[2] Herein, a sustainable biophotoanode based on intact purple bacteria is utilized for the monitoring of phenol-class contaminants that affects photocurrent generation. Specifically, we focused on nitro-phenols and other phenols that might be released in water when food/agricultural wastes are disposed into the environment. All the investigated compounds are known to be toxic, affecting both humans and animals’ health. Furthermore, to follow the green chemistry and bio-circular economy principles, approaches for the possible removal/recovery of these phenols and their degradation products were also investigated, with their possible re-use as active compounds in biomedical applications.[3] Challenges and future research directions for the application of these systems in the field will be discussed.
References:
[1] M. Grattieri, Purple bacteria photo-bioelectrochemistry: enthralling challenges and opportunities, Photochem. Photobiol. Sci., 19 (2020) 424-435.
[2] M. Grattieri, K. Beaver, E.M. Gaffney, F. Dong, S.D. Minteer, Advancing the fundamental understanding and practical applications of photo-bioelectrocatalysis, Chem. Commun., 56 (2020) 8553-8568.
[3] J. Gubitosa, V. Rizzi, A. Lopedota, P. Fini, A. Laurenzana, G. Fibbi, F. Fanelli, A. Petrella, Laquintana, N. Denora, R. Comparelli, P. Cosma, One pot environmental friendly synthesis of Gold Nanoparticles using Punica Granatum Juice: a novel antioxidant agent for future dermatological and cosmetic applications, J. Colloid Interface Sci. 521 (2018) 50–61.
Electrochemical Bioremediation of Uranium VI Using Geobacter Sulfurreducens on Boron-Doped Diamond Electrode Surface
Authors: Acevedo Alexis J. , Cabrera Carlos R. , Toranzos Gary 
Published: July 2022

The development of nuclear science and technology has led to increasing nuclear waste containing uranium. The contamination associated with nuclear activity, especially uranium, is a significant concern for human and environmental health. Due to the high toxicity, radioactivity, and extensive half-life of uranium, it is necessary to find a way to remove it from the environment. One alternative to solve this problem is bioremediation. With this technique, microorganisms can be used to reduce, eliminate, contain, or transform hazardous waste like radionuclides. This research proposes using the bacteria Geobacter sulfurreducens to reduce uranium (VI) (U(VI)) to uranium (IV) (U(IV)). The experiment consists in the G. sulfurreducens' immobilization using the boron-doped diamond electrodes (BDD) as an electron donor by electrochemical processes. Taking advantage of the bacteria's microbial metabolism process and using U (VI) as an electron acceptor will reduce the ion to U (IV). First, a potential of -500mV (vs. Ag/AgCl) will be applied to immobilize the G. sulfurreducens’ to the BDD electrode surface. Second, with the application of a potential between -500mV to -700mV (vs. Ag/AgCl), it will expect to reduce the uranium ion and remove it from the media. Preliminary studies of the behavior of BDD electrodes in the presence of U(VI) had been carried out to determine the electrochemical conditions at which the substrate works with this ion. The results found with these studies will show how G. sulfurreducens’ will improve U(VI) bioremediation through electrochemical processes.
This research has the financial support from the DOE- Minority Serving Institutions Partnership Program, National Nuclear Security Administration, "Scholarly Partnership in Nuclear Security (SPINS)", Grant Number DE NA0003980.

Figure 1
Electrochemical Characterization of Auranofin in Aqueous Media
Authors: Yosseif Melak , Singh Vikram , Maydaniuk Dustin , Cardona Silvia , Kuss Sabine 
Published: July 2022

Detection of antibiotic compounds in various media is necessary in solving the public health crisis of antibiotic resistance[1]. Auranofin (AF) is a repurposed antibiotic first used as an antirheumatic in the 1950s. It is useful against various bacteria, fungi, virus infections and cancers either by itself or synergistically with other antibiotics[2–5]. AF is composed of aurothioglucose and phosphine moieties, and therefore, has lipophilic and hydrophilic properties, making its characterization in aqueous media particularly difficult. In the presented study, electrochemistry was employed to characterize and detect AF in aqueous solutions using modified glassy carbon electrodes (GCEs), coated with Carbon Black (CB). CB coating was optimized, oxidation and reduction potentials were identified, and pH dependence, as well as Limits of Detection (LOD) and Quantification (LOQ) were determined. Interferences with ions and other antibiotics was studies and are important factors for the detection of AF in the environment. This study reports on the sensitivity, stability, and selectivity of the CB-GCE sensors, proving useful for future field detection and/or bioelectrochemical investigations.
CITATIONS
[1] M.R. Islam, S. Kuss, F. Schweizer, Characterization of Antibiotic Compounds By Electrochemistry, ECS Meeting Abstracts. MA2020-01 (2020). https://doi.org/10.1149/ma2020-01442531mtgabs.
[2] R. Díez-Martínez, E. García-Fernández, M. Manzano, Á. Martínez, M. Domenech, M. Vallet-Regí, P. García, Auranofin-loaded nanoparticles as a new therapeutic tool to fight streptococcal infections, Scientific Reports. 6 (2016). https://doi.org/10.1038/srep19525.
[3] K.J. Habermann, L. Grünewald, S. van Wijk, S. Fulda, Targeting redox homeostasis in rhabdomyosarcoma cells: GSH-depleting agents enhance auranofin-induced cell death, Cell Death & Disease. 8 (2017). https://doi.org/10.1038/cddis.2017.412.
[4] E. v. Capparelli, R. Bricker-Ford, M.J. Rogers, J.H. McKerrow, S.L. Reed, Phase I clinical trial results of auranofin, a novel antiparasitic agent, Antimicrobial Agents and Chemotherapy. 61 (2017). https://doi.org/10.1128/AAC.01947-16.
[5] T. Onodera, I. Momose, M. Kawada, Potential anticancer activity of auranofin, Chemical and Pharmaceutical Bulletin. 67 (2019). https://doi.org/10.1248/cpb.c18-00767.
3D-Branched Fe2O3 Nanorods on Micropillar Arrays Decorated with Co-Pi for Enhanced PEC Water Splitting
Authors: Kim Nak Hyun , Ju Sucheol , Park Jaemin 
Published: July 2022

Photoelectrochemical(PEC) water splitting has gained great attention as a route for future hydrogen production owing to its sustainable and cost-effective properties. However, since PEC water splitting has limitations on efficiency and stability, research on materials, structures and catalysts are in progress to solve those problems. In our experiments, the nano-pattern structure is created using direct-printing to increase the photoanode efficiency.
In this study, enlarged surface area is accomplished by micropillar structured FTO and Fe2O3 nanorods. We fabricated micropillar structure via direct printing method. The direct-printing method has advantages in not only simple process but also low price to form micro-nano size structures. To obtain micropillar structure, spin coating of hydrogen silsesquioxane(HSQ) was performed on micropillar patterned polydimethylsiloxane(PDMS) mold. Then, we applied glass substrate and pressure on it. Detachment of PDMS mold is followed by deposition of FTO layer. Hydrothermally synthesized Fe2O3 nanorods are formed on micropillar structured FTO and Co-Pi catalyst was electrodeposited on Fe2O3 nanorods to enhance surface water oxidation.
Due to micropillar pattern, optical absorption of patterned Fe2O3 photoanode is higher than that of flat Fe2O3 photoanode in the whole range of optical wavelength. Also micropillar patterned Fe2O3 sample showed 2.6 times higher photocurrent at 1.23 VRHE than flat Fe2O3 sample. These results were confirmed that micropillar structure increased the surface area and light scattering effect. Furthermore, applying Co-Pi catalyst increased photocurrent at 1.23 VRHE for 2.0 times higher owing to the enhancement of surface water oxidation. As a result, photocurrent of the micropillar patterned, decorated with Co-Pi sample shows 1.51 mA/cm2, and that of flat, non-decorated sample shows 0.29 mA/cm2 at 1.23 VRHE.

Figure 1