Electron Flow Research Articles

RECENT ADVANCEMENT IN ELECTROCHEMICAL BIOSENSOR BASED ON REDOX ENZYME COMPOSITE MODIFIED ELECTRODE FOR THE DETECTION OF BIOMOLECULES

Recent developments in electrochemical biosensors have resulted in new applications in a variety of disciplines, such as clinical diagnosis, food processing quality control, and environmental monitoring. The electrochemical biosensor is a widely used sensing device that transmits an electrical signal from biological activities. Electrochemical biosensors have led to significant advancements in detecting various biomolecules such as uric acid, glucose, cholesterol, lactate, and DNA, including cancer biomarkers, viruses, and antibodies. An electrode is a vital part of this kind of sensor since it serves as a strong support for immobilizing biomolecules (enzyme, antibody, and nucleic acid) and allowing electron flow. Redox enzymes are the foundation of enzymatic electrochemical biosensors, which use oxidation or reduction reactions to detect a substrate, which is then converted into an electrical signal. Immobilizing enzymes onto solid supports is a common method to enhance the performance of an enzymatic electrochemical biosensor. However, there are some challenges, such as potential loss of enzyme activity, difficulties in maintaining enzyme stability, and issues related to the reproducibility and consistency of enzyme immobilization. This review covers all challenges in enzymatic electrochemical biosensors. Numerous new biosensor platforms are announced each year as researchers look for various electrode materials. Additionally, the researchers should familiarize themselves with the practical methods used in electrode production in order to build a successful biosensor. This review highlights current developments in modifying enzyme-immobilized biosensors for detection of different biomolecules. The article further describes methods of enzyme immobilization and various enzymes with different nanomaterials for the development of novel enzymatic electrochemical biosensors.

Fulvic acid mediated highly efficient heterotrophic nitrification-aerobic denitrification by Paracoccus denitrificans XW11 with reduced C/N ratio

Reducing the C/N ratio requirements for heterotrophic nitrification-aerobic denitrification (HNAD) is crucial for its practical application; however, it remains underexplored. In this study, a highly efficient HNAD bacterium, Paracoccus denitrificans XW11, was isolated. The HNAD characteristics of XW11 were studied, and the redox mediator fulvic acid (FA) was used to reduce the C/N requirements. Whole-genome sequencing revealed multiple denitrification genes in XW11; however, nitrification genes were not identified, because heterotrophic nitrification-related gene sequences were not included in the database. However, the nitrogen removal related enzyme activity test revealed complete nitrification and denitrification pathways. Reverse transcription PCR showed that the membrane-bound nitrate reductase (NarG), rather than the periplasmic nitrate reductase, was responsible for aerobic denitrification. The conventional nitrite reductase (NirS) also does not mediate nitrite denitrification. When the C/N ratio was 10, the ammonia removal efficiency of the Control was 71.71 % and the addition of FA increased it to 86.12 %. Transcriptomic analysis indicated electron flow from the carbon source to FA without proton transmembrane transport, and the presence of FA constructs another electron transfer system. The redox potential of oxidized FA/reduced FA is 0.3679 V, avoiding competition for electrons from Complex III. Thus, ammonia monooxygenase obtains electrons more easily, thereby promoting nitrification. The enzyme activity test of the nitrification process confirmed this view. In addition, NarG expression increased, and the denitrification process was enhanced. Overall, FA improved HNAD efficiency by facilitating electron transfer to the nitrogen dissimilation process, offering a novel approach to reduce the C/N requirement of HNAD.

Synergistic Gradient Anodes for Long-Term Stability in Aqueous Zinc-Ion Batteries.

The stability of aqueous zinc metal anodes is still constrained by their severe dendrite growth. Optimizing electric field distribution and crystallography to modulate the diffusion and deposition behavior of zinc ions can effectively suppress dendrite growth. However, the fabrication strategy to directly endow specific textured zinc anodes with gradient electric field distribution is still lacking. Herein, a strategy combining crystal reconstruction of commercial zinc foil with graphene oxide (GO) protective layer is proposed to construct an in situ gradient electric field-enhanced strong (002) textured GO@ZnO/Zn(002) anode. Based on the experimental and theoretical results, the GO protective layer can regulate a wide-range homogeneous Zn2+ ions flow, while the dense and uniform ZnO/Zn(002) nanoneedles /nanoparticles can enhance localized polarized electric field to accelerate rapid localized transfer of Zn2+ ions and guide them toward directional deposition along (002) plane. Therefore, the hierarchical GO@ZnO/Zn(002) anode enables the symmetric cell to operate continuously and stably for 5700 and 4200h at 2 and 4mA cm-2, respectively, which is comparable to or better than most high-end Zn anodes. This work presents new insights into the zinc foil reconstruction and gradient electric field fabrication strategy, offering a scalable approach for the development of long-term stable metal anodes.

Slack Channels as Key Regulators of Neuronal Excitability: Implications for Neural Function and the Link to Epilepsy Pathogenesis

The Slack channel encoded by the KCNT1 gene is a sodium-activated potassium channel. By regulating the flow of potassium ions, the Slack channel affects the membrane potential and discharge activity of neurons, thus participating in regulating neuronal excitability. Therefore, it plays a crucial role in maintaining the normal function of the nervous system. Consequently, abnormal Slack channel function is closely linked to various neurological diseases, such as epilepsy. Currently, quinidine-based medication therapy and neuroregulatory therapy are key components of the treatment of epilepsy resulting from Slack channel dysfunction. This article aims to outline the fundamental features of the Slack channel while providing a thorough analysis of the main distinctions and possible connections between Slick and Slack channels. Furthermore, this study focuses on the function of controlling the neuronal excitability of Slack channels while delving deeper into the potential correlation between Slack channels and epilepsy and their treatment strategies.

«KEGOC» КОМПАНИЯСЫНДА ӨНДІРІСТІК ЖАРАҚАТТАНУДЫҢ АЛДЫН АЛУДЫ ТАЛДАУ

This article discusses the problem of occupational injury prevention at «KEGOC». The authors analyze the current situation and present their recommendations for improving the occupational safety management system. The main focus is on electrical safety, which includes protection measures against the effects of electric current, electromagnetic field, electric arc and static electricity. The article presents data on the most common ways of passing current in the human body and on the effects of electricity on the body. «KEGOC» strives to create working conditions that meet the requirements of safety and hygiene, and is actively developing, using modern technologies and striving to increase its value for all stakeholders. The company is also actively engaged in social responsibility, implementing energy efficiency projects and environmental programs. The authors pay special attention to occupational safety and industrial safety. In particular, they emphasize the need to create safe working conditions, minimize injuries, improve production and sanitary conditions, as well as reduce the impact of harmful and adverse factors. In this context, the use of a health and safety management system is mentioned, which covers all structural divisions and subsidiaries of the company. An important aspect is the conduct of a behavioral safety audit and the implementation of the «KEGOC» JSC program on the occupational safety and health management system in accordance with the international standard ISO 45001. It also mentions the annual and shift medical examinations of employees and the availability of special labor protection services in each branch of the company. The article discusses the results of the analysis of occupational injuries and concludes that there is a need for continuous improvement of the risk management system and the introduction of innovative approaches to achieve maximum efficiency in the field of occupational safety and industrial safety.

Inhibition of sulfur assimilation by S-benzyl-L-cysteine: Impacts on growth, photosynthesis, and leaf proteome of maize plants

Sulfur is an essential nutrient for various physiological processes, including protein synthesis and enzyme activation. We aimed to evaluate how S-benzyl-L-cysteine (SBC), an inhibitor of the sulfur assimilation pathway, affects maize plants' growth, photosynthesis, and leaf proteomic profile. Thus, maize plants were grown for 14 days in vermiculite supplemented with SBC. Photosynthesis was assessed using light and CO2 response curves and chlorophyll a fluorescence. Leaf proteome analysis was conducted to evaluate photosynthetic protein biosynthesis, and ROS content was quantified to assess oxidative stress. Applying SBC resulted in a significant decrease in the growth of maize plants. The gas exchange analysis revealed that maize plants exhibited a diminished rate of CO2 assimilation attributable to both stomatal and non-stomatal limitations. Furthermore, SBC suppressed the activity of important elements involved in the photosynthetic electron transport chain (including photosystems I and II, cytochrome b6f, and ATP synthase) and enzymes responsible for the Calvin cycle, some of which have sulfur-containing prosthetic groups. Consequently, the diminished electron flow rate resulted in a substantial increase in the levels of ROS within the leaves. Our research highlights the crucial role of SBC in disrupting maize photosynthesis by limiting L-cysteine and assimilated sulfur availability, which are essential for the synthesis of protein and prosthetic groups and photosynthetic processes, emphasizing the potential of OAS-TL as a new herbicide site of action.

The VEGFA-Induced MAPK-AKT/PTEN/TGFβ Signal Pathway Enhances Progression and MDR in Gastric Cancer.

Gastric cancer (GC) is a globally frequent cancer, in particular leading in mortality caused by digestive tract cancers in China. Vascular endothelial growth factor A (VEGFA) is excessively expressed in cancers including GC; its involvement in GC development, particularly in multidrug resistance (MDR), and the signal route it affects in GC remain unknown. To explore the roles VEGFA plays during progression and MDR formation in GC, we studied its function in a VEGFA-deleted GC cell platform. We initially assessed the importance of VEGFA in GC and MDR using database analysis. Then, using CCK8, wound healing, transwell, scanning electron microscopy, immunofluorescence, flow cytometry, and other techniques, the alterations in tumor malignancy-connected cell behaviors and microstructures were photographed and evaluated in a VEGFA-gene-deleted GC cell line (VEGFA-/-SGC7901). Finally, the mechanism of VEGFA in GC progression and MDR was examined by Western blot. Database analysis revealed a strong correlation between high VEGFA expression and a poor prognosis for GC. The results showed that VEGFA deletion reduced GC cell proliferation and motility and altered microstructures important for motility, such as the depolymerized cytoskeleton. VEGFA deletion inhibited the growth of pseudopodia/filopodia and suppressed the epithelial-mesenchymal transition (EMT). The occurrence of MDR is induced by overactivation of the MAPK-AKT and TGFβ signaling pathways, while PTEN inhibits these pathways. All findings suggested that VEGFA acts as a cancer enhancer and MDR inducer in GC via the MAPK-AKT/PTEN/TGFβ signal pathway.

Spatially Separate Center-to-Surround Radiation Structure Induced Tandem Electron Transfer Effect for Stable and Enhanced Photocatalysis.

Spatially separate anchoring redox cocatalysts on the photocatalyst to shunt the charge migration paths is an effective route to regulate the charge flow. Differently, we herein introduce an artificially synthesized Sun-planet-like spatially separated center-to-surround radiation photosensitizer-cocatalyst structure to regulate electron flow in a tandem manner. A single Au sphere acts as the Sun/photosensitizer in the center, and small Pt particles scatter around as the planets/cocatalyst, both of which are fixed inside the MOF crystal. Such a structure can not only simultaneously increase the light harvesting capacity and electron migration kinetics but also optimize the electron transfer pathway to minimize the electron migration distance, so that the hot electrons generated by Au can be quickly transferred to Pt through MOF before annihilation, leading to a significant photoactivity promotion.

Effect of Environmental and Anthropic Conditions on the Development of Solanum peruvianum: A Case of the Coastal Lomas, Lima-Peru

Land degradation and the effects of climate change are increasing arid lands, accelerating desertification, and leading to the loss of ecosystem services worldwide. This research focused on evaluating how human impact and environmental factors affect the development of Solanum peruvianum in its natural habitat of coastal lomas. The study was carried out in the coastal lomas of Mangomarca-Peru, where phenotypic and ecological data on the plants were collected. Information was also gathered on human impacts on the nutritional characteristics of the soils. Then, five types of organic amendments were used to improve the physical and chemical characteristics of the degraded soil, and the development and photosynthetic activity of S. peruvianum were evaluated. As a result, under the study conditions, it was found that S. peruvianum was established approximately 33.74 cm from the rocks, in a range of 300 to 650 m asl. The maximum height of the plants was 90 cm, with a stem diameter at ground level of 2 cm. S. peruvianum produced fruits between January and July, with a seed germination rate of 36% in 25 days. On the other hand, the anthropogenic impact on the soil reduced 58% of organic material (OM), 71% of nitrogen, 40% of P2O5, and 13% of K2O and increased the concentration of magnesium oxide, calcium oxide, pH, and electric conductivity (EC). The organic amendments bokashi, compost, and biochar, when mixed with the degraded soil, increased the pH, OM, N, P, and EC; however, the plants died after 25 days. On the other hand, the application of the Premix5 substrate for 100 days favored the growth of 52.84 cm and 38.29 cm in the preserved soil and 23.21 cm in the black soil mixed with blond peat, and it should be noted that the substrates presented an acid pH and EC > 0.1. Regarding photosynthetic phenotyping, S. peruvianum plants grown in their natural habitat and in Premix5 showed a higher proton flux (vH+), linear electron flow (LEF), and maximum quantum yield (Fv’/Fm’). On the contrary, they showed a lower NPQt value than plants grown in preserved and black soil mixed with blond peat.

Nutrient removal performance and the nitrogen-sulfur conversion pathways in sulfur-iron based biofilter under acidic/alkaline conditions

The nitrate and phosphate removal in sulfur based (Vp) and sulfur-iron based autotrophic denitrification systems (Sp) with sponge iron as the iron source was investigated under different pH (6–9). In this study, Sp (>98 %) and Vp (>97 %) had higher nitrate removal efficiency at pH 7–8 and the highest phosphate removal efficiency (94.9 % ± 3.57 %) at pH 6. The flow cytometry detection revealed that the cell integrity was damaged due to the formation of iron crusts at pH 6, which resulted in irreversible inhibition in Sp. Electron transfer and nitrogen transformation showed that compared with the sustained inhibition of denitrification at pH 6, the inhibition at pH 9 occurred mainly in the initial 0–2 h due to the enhanced flow of electrons toward the formation of biological element sulfur (Sbio0). Coupled sponge iron promoted the adsorption and reduction of NO2−/N2O and reduced N2O emissions. Metatranscriptomics analysis showed that significant upregulation of key gene expression for nitrogen and sulfur metabolism in Sp, with complex regulatory mechanisms enhancing system stability and performance. Acidic conditions reduced the abundance of denitrification and sulfur oxidation functional genes. However, alkaline conditions (pH of 9) mainly caused the decreased abundance of denitrification functional genes, which was favorable for accumulation of Sbio0. This study provides a theoretical basis for the stable operation and regulation of the sulfur-iron based autotrophic denitrification process.

Electron Collimation in Twisted Bilayer Graphene via Gate-Defined Moiré Barriers.

Electron collimation via a graphene p-n junction allows electrostatic control of ballistic electron trajectories akin to that of an optical circuit. Similar manipulation of novel correlated electronic phases in twisted-bilayer graphene (tBLG) can provide additional probes to the underlying physics and device components toward advanced quantum electronics. In this work, we demonstrate collimation of the electron flow via gate-defined moiré barriers in a tBLG device, utilizing the band-insulator gap of the moiré superlattice. A single junction can be tuned to host a chosen combination of conventional pseudo barrier and moiré tunnel barriers, from which we demonstrate improved collimation efficiency. By measuring transport through two consecutive moiré collimators separated by 1 μm, we demonstrate evidence of electron collimation in tBLG in the presence of realistic twist-angle inhomogeneity.

Enhancing Efficiency of Dye-Sensitized Solar Cell using Mn or Ce Doped and Co-doped ZnO Photoanodes with Lawsonia Inermis Natural Dye

Abstract In the present research paper, Mn (transition metal) and Ce (rare earth metal) doped and co-doped ZnO nanoparticles were synthesized using a cost-effective sol-gel technique. As synthesized samples were characterized using X-ray diffraction and field emission scanning electron microscope to examine the structure and morphology respectively. The optical properties were examined by UV-Visible and photoluminescence spectroscopic techniques. The synthesized samples were used as photoanode for the fabrication of dye-sensitized solar cell (DSSC). The utilization of a photoanode, containing Mn and Ce doped and co-doped in ZnO, in DSSC leads to a significant enhancement in photovoltaic conversion efficiency with natural dye lawsonia inermis. Different combinations of Mn or Ce doped and co-doped ZnO nanoparticles were used for testing their effectiveness as photoanode in DSSC. It was observed that the efficiency for Mn and Ce co-doped ZnO photoanode-based DSSC was found to be 0.2118%, which is approximately a 750% increase as compared to bare ZnO photoanode based DSSC. The enhancement in the efficiency of DSSCs was due to the formation of a blocking layer by Mn ions which helps to stop the flow of electrons backward and the broadening of the spectrum region with the help of Ce ions using up/down conversion process also helps to achieve higher efficiency. This enhancement in the efficiency of DSSC may be attributed to the synergic effect of Mn and Ce.

Photo-induced BiVO4 to produce P25-like structure for enhancing piezo-photocatalytic activity

Piezo-photocatalysis is considered a promising pollutant treatment strategy. Herein, a simple strategy is proposed to construct lattice distortion in BiVO4 to realize an efficient piezo-photocatalytic degradation process. Specifically, the phase structure of BiVO4 is regulated by introducing different wavelengths of illumination, resulting in the homojunction formation. Compared with BiVO4 prepared under dark conditions (BVO), the VO bonds are shortened and the BiO bonds are elongated in the structure of BiVO4 synthesized under 460 nm illumination (BVO-460). Furthermore, the Tafel curve reveals that electrons flow from the monoclinic phase to the tetragonal phase. By the tetracycline hydrochloride degradation, it is found that the BVO-460 has excellent piezo-photocatalytic efficiency, attributed to the piezoelectric polarization field enhanced charge transfer. In this paper, the piezo-photocatalytic performance of BiVO4 is investigated in the insight of crystal phase structure, which provided a new idea for the application of layered bismuth-based materials in environmental purification.

Biogenic amorphous FeOOH activated additional intracellular electron flow pathways for accelerating reductive dechlorination of tetrachloroethylene

Dissimilatory iron-reducing bacteria (DIRB) with extracellular electron transfer (EET) capabilities have shown significant potential for bioremediating halogenated hydrocarbon contaminated sites rich in iron and humic substances. However, the role and microbial molecular mechanisms of iron-humic acid (Fe-HA) complexes in the reductive dehalogenation process of DIRB remains inadequately elucidated. In this study, we developed a sustainable carbon cycling approach using Fe-HA complexes to modulate the electron flux from sawdust (SD), enabling almost complete reductive dechlorination by most DIRB (e.g., Shewanella oneidensis MR-1) that lack complex iron-sulfur molybdo enzymes. The SD-Fe-HA/MR-1 system achieved a 96.52% removal efficiency of tetrachloroethylene (PCE) at concentrations up to 250 μmol/L within 60 days. Material characterization revealed that DIRB facilitated the hydrolysis of macromolecular carbon sources by inducing the formation of amorphous ferrihydrite (FeOOH) in Fe-HA complexes. More importantly, the bioavailable FeOOH activated additional intracellular electron flow pathways, increasing the activity of potential dehalogenases. Transcriptome further highlight the innovative role of biogenic amorphous FeOOH in integrating intracellular redox metabolism with extracellular charge exchange to facilitate reductive dechlorination in DIRB. These findings provide novel insights into accelerating reductive dechlorination in-situ contaminated sites lacking obligate dehalogenating bacteria.

Photosynthetic Responses to Salt Stress in Two Rice (Oryza sativa L.) Varieties

Assessing salt tolerance in plants under field conditions is a challenging task. The objective of this research was to assess the effectiveness of different methods (leaf disc assay and pot experiment) for evaluating salt tolerance in rice. Using two varieties with different salt tolerance, Changmaogu (CM) and 9311, under three NaCl levels (0, 0.3%, and 1.0%), we evaluated the photosynthetic performance in terms of chlorophyll content in leaf disc assays, as well as the photosynthetic rate (Pn), chlorophyll content, linear electron flow (LEF), and non-photochemical quenching (NPQ), in a semi-controlled pot experiment. In the leaf disc assay, CM showed a smaller decrease in chlorophyll content compared to 9311, especially under 1.0% salinity. Simultaneously, in the pot experiment, the CM variety employed flexible photosynthetic strategies, actively decreasing LEF and Pn after 5 days of salt stress (day 5) and then increasing photosynthetic capacity (chlorophyll content, LEF, and Pn) on day 10. Notably, the total chlorophyll content for the CM variety under 1.0% salinity was significantly higher than in the control, showing a 25.0% increase. Additionally, CM demonstrated NPQt sensitivity under 0.3% salinity, requiring an LEF of 150 to achieve an NPQt value of 3.0, compared to an LEF of 180 in the control. These results suggest that a simple leaf disc assay may not fully capture the adaptive mechanisms of rice plants under salinity stress. Therefore, we advocate for the use of more comprehensive methods, such as outdoor pot or field experiments, to gain a deeper understanding and more accurate evaluation of salt tolerance in rice.

Pseudomonas Stutzeri may alter the environmental fate of polystyrene nanoplastics by trapping them with increasing extracellular polymers

Pseudomonas Stutzeri (P. stutzeri) is a denitrifying bacterium that is essential in biological nitrogen removal. To study the interaction between P. stutzeri and polystyrene nanoplastics (PS-NPs), the effects of PS-NPs posed on P. stutzeri were evaluated in terms of bacterial growth, physiology, denitrification function and extracellular polymers (EPS) secretion. Results of confocal laser scanning microscopy (LCSM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and flow cytometry confirmed that PS-NPs were trapped by P. stutzeri. Exposure to PS-NPs inhibited bacterial growth and expression of denitrification-related genes, but unaffected the denitrifying enzyme activities. The enhanced secretion of EPS caused PS-NPs and bacterial aggregation. And the enzyme activity of SOD in P. stutzeri was increased while that of CAT was decreased. The results of flow cytometry showed that high concentrations of PS-NPs increased the complexity of P. stutzeri cells. These results reveal that P. stutzeri may be affected after trapping PS-NPs and alter their environmental fate as well. SynopsisThis study contributes to the understanding of the possible effect of P. stutzeri on the distribution of PS-NPs and illustrates the potential impact of PS-NPs on P. stutzeri.

Dynamic transition and Galilean relativity of current-driven skyrmions.

The coupling of conduction electrons and magnetic textures leads to quantum transport phenomena described by the language of emergent electromagnetic fields1-3. For magnetic skyrmions, spin-swirling particle-like objects, an emergent magnetic field is produced by their topological winding4-6, resulting in the conduction electrons exhibiting the topological Hall effect (THE)7. When the skyrmion lattice (SkL) acquires a drift velocity under conduction electron flow, an emergent electric field is also generated8,9. The resulting emergent electrodynamics dictate the magnitude of the THE by the relative motion of SkL and conduction electrons. Here we report the emergent electrodynamics induced by SkL motion in Gd2PdSi3, facilitated by its giant THE10,11. With increasing current excitation, we observe the dynamic transition of the SkL motion from the pinned to creep regime and finally to the flow regime, in which the THE is totally suppressed. We argue that the Galilean relativity required for the total cancellation of the THE may be generically recovered in the flow regime, even in complex multiband systems such as the present compound. Moreover, the observed THE voltages are large enough to enable real-time measurement of the SkL velocity-current profile, which shows the inertial-like motion of the SkL in the creep regime, appearing as the current hysteresis of the skyrmion velocity.

Steric hindrance and orientation polarization by a zwitterionic additive to stabilize zinc metal anodes

AbstractZinc metal stands out as a promising anode material due to its exceptional theoretical capacity, impressive energy density, and low redox potential. However, challenges such as zinc dendrite growth, anode corrosion, and side reactions in aqueous electrolytes significantly impede the practical application of zinc metal anodes. Herein, 3‐(1‐pyridinio)‐1‐propanesulfonate (PPS) is introduced as a zwitterionic additive to achieve long‐term and highly reversible Zn plating/stripping. Due to the orientation polarization with the force of electric field, PPS additive with π–π conjugated pyridinio cations and strong coordination ability of sulfonate anion tends to generate a dynamic adsorption layer and build a unique water–poor interface. PPS with steric hindrance effect and strong coordination ability can attract solvated Zn2+, thereby promoting the desolvation process. Moreover, by providing a large number of nucleation sites and inducing zinc ion flow, the preferred orientation of the (002) crystal plane can be achieved. Therefore, the interfacial electrochemical reduction kinetics is regulated and uniform zinc deposition is ensured. Owing to these advantages, the Zn//Zn symmetrical cell with PPS additive exhibits remarkable cycling stability exceeding 2340 h (1 mA cm−2 and 1 mA h cm−2). The Zn//V2O5 full cell also delivers stable cycling for up to 6000 cycles.

Heterostructure WSe2/copper hexadecafluorophthalocyanine (F16CuPc) field-effect transistors for efficient suppression of electron transport

The use of the organic semiconductor copper hexadecafluorophthalocyanine (F16CuPc) in WSe2 based heterostructure field-effect transistors (FETs) is shown to result in a large reduction in electron current while not significantly impacting the hole current. This approach is promising for use in p-channel FETs in which electron transport is undesirable and increases leakage currents and power dissipation in the off-state. The reduction in on-state electron currents, by up to three orders of magnitude, is due to the transfer of electrons to the low-mobility states in F16CuPc due to the greater electron affinity of the organic semiconductor compared to WSe2. The off-state currents under a drain bias are reduced by more than four orders of magnitude due to the effective suppression of electron currents. This is a result of the formation of type II heterostructure between F16CuPc and WSe2. Electrons in this heterostructure FET will preferentially transfer to F16CuPc, while holes will tend to remain in the high mobility WSe2 layer. This effect is more marked in monolayer WSe2 based FETs compared to multilayer WSe2 FETs due to a larger difference in electron affinities with respect to F16CuPc. Also, the magnitude of electron current suppression was further enhanced when F16CuPc is deposited only on a part of the channel near the source of WSe2 +F16CuPc FETs.

Enhancing electrical conductivity of RuO2 nanosheet-coated films by enlarging the nanosheet area

This study focused on enhancing the electrical conductivity of metal oxide nanosheet films by increasing the size of the nanosheets to promote the electron flow in the desired in-plane direction. We developed a method for increasing the size of RuO2 metal oxide nanosheets, a 2D material, by controlling the heat-treatment process. The size of the RuO2 nanosheets increased from 0.7 to 3.5 μm by modifying the heat-treatment conditions of KxRuO2, which was used as the precursor material. As a consequence, the electrical conductivity of the large-sized-RuO2 nanosheet-coated films was eight times higher than that of their small-sized counterparts. This lower resistance was attributed to the minimal number of contacts required for electron flow; the contact resistance between the nanosheets being higher than the intrinsic resistance. The proposed approach for enhancing the conductivity of metal oxide 2D materials is very promising and is expected to significantly contribute to the development of advanced flexible electronic devices.