Evaluation of the effect of precursor ratios on the electrochemical performances of binder-free NiMn-phosphate electrodes for supercapattery

Binary metal phosphate electrodes have been widely studied for energy storage applications due to the synergistic effects of two different transition elements that able to provide better conductivity and stability. Herein, the battery-type binder-free nickel-manganese phosphate (NiMn-phosphate) electrodes were fabricated with different Ni:Mn precursor ratios via microwave-assisted hydrothermal technique for 5 min at 90 °C. Overall, NiMn3P electrode (Ni:Mn = 1:3) showed an outstanding electrochemical performance, displaying the highest specific (areal) capacity at 3 A/g of 1262.4 C/g (0.44 C/cm2), and the smallest charge transfer resistance of 108.8 Ω. The enhanced performance of NiMn3P electrode can be ascribed to the fully grown amorphous nature and small-sized flake and flower structures of NiMn3P electrode material on the nickel foam (NF) surface. This configuration offered a higher number of active sites and a larger exposed area, facilitating efficient electrochemical reactions with the electrolyte. Consequently, the NiMn3P//AC electrode combination was chosen to further investigate its performance in supercapattery. The NiMn3P//AC supercapattery exhibited remarkable energy density of 105.4 Wh/kg and excellent cyclic stability with 84.7% retention after 3000 cycles. These findings underscored the superior electrochemical performance of the battery-type binder-free NiMn3P electrode, and highlight its potential for enhancing the overall performance of supercapattery.

Impact of UV radiation on Mxene-mediated tubulin dissociation and mitochondrial apoptosis in breast cancer cells

Breast cancer is a global health concern that requires personalized therapies to prevent relapses, as conventional treatments may develop resistance over time. Photothermal therapy using spectral radiation or intense light emission is a broad-spectrum treatment that induces hyperthermia-mediated cancer cell death. MXene, a two-dimensional material, has been reported to have potential biological applications in photothermal therapy for cancer treatment. In this study, we investigated the apoptotic activity of MXene and UV-irradiated MXene in MCF-7 breast cancer cells by treating them with varying concentrations of MXene. The cytotoxicity of MXene and UV was evaluated by analyzing cellular morphology, nuclei condensation, caspase activation, and apoptotic cell death. We also assessed the effect of the combined treatment on the expression and cellular distribution of Tubulin, a key component of microtubules required for cell division. At low concentrations of MXene (up to 100 µg/ml), the level of cytotoxicity in MCF-7 cells was low. However, the combined treatment of MXene and UV resulted in a synergistic increase in cytotoxicity, causing rounded cellular morphology, condensed nuclei, caspase activation, and apoptotic cell death. Furthermore, the treatment reduced Tubulin protein expression and cellular distribution, indicating a potent inducer of cell death with potential application for cancer treatment. The study demonstrates that the combined treatment of MXene and UVB irradiation is a promising strategy for inducing apoptotic cell death in breast cancer cells, suggesting its potential as a therapeutic intervention for breast cancer.

Facile and Affordable Design of MXene-Co3 O4 -Based Nanocomposites for Detection of Hydrogen Peroxide in Cancer Cells: Toward Portable Tool for Cancer Management

Hydrogen peroxide (H2 O2 ) is a primary reactive oxygen species (ROS) that can act as a chemical signal in developing and progressing serious and life-threatening diseases like cancer. Due to the stressful nature of H2 O2 , there is an urgent need to develop sensitive analytical approaches to be applied to various biological matrices. Herein, a portable point-of-care electrochemical system based on MXene-Co3 O4 nanocomposites to detect H2 O2 in different cancer cell-lines is presented. The developed sensor is affordable, disposable, and highly selective for H2 O2 detection. This approach achieves a dynamic linear range of 75 µm with a LOD of 0.5 µm and a LOQ of 1.6 µm. To improve the practical application, the level of ROS is evaluated both in cancer cell lines MDA-MB-231 and DU145, respectively, to breast and prostate cancers, and in healthy HaCat cells. Moreover, the same cancer cells are treated with transforming growth factor-β1, and MXene-Co3 O4 modified strip is capable to monitorROS variation. The results are satisfactory compared with the cellular ROS fluorescent assay based on DCFH/DCFH-DA. These results open new perspectives for real-time monitoring of cancer progression and the efficacy of the therapy.

Silver Decorated and Graphene Wrapped Polypyrrole@Ni(OH)2 Quaternary Nanocomposite for High Performance Energy Storage Devices

In this work, silver (Ag) anchored over graphene (GN) wrapped polypyrrole (PPy)@ nickel hydroxide (Ni(OH)₂) nanocomposites were synthesized through a combination of oxidative polymerization and hydrothermal processes. The synthesized Ag/GN@PPy-Ni(OH)₂ nanocomposites were characterized for their morphological characteristics by field emission scanning electron microscopy (FESEM), while the structural investigations were done by X-ray diffraction and X-ray photoelectron spectroscopy (XPS). The FESEM studies showed Ni(OH)₂ flakes and silver particles attached over the surface of PPy globules, along with the presence of GN sheets and spherical silver particles. The structural analysis also showed the presence of constituents, i.e., Ag, Ni(OH)₂, PPy, GN, and their interaction, therefore vouching that the synthesis protocol is efficacious. The electrochemical (EC) investigations were done in potassium hydroxide (1 M KOH) using a three electrode setup. The quaternary Ag/GN@PPy-Ni(OH)₂ nanocomposite electrode showed the highest specific capacity of 237.25 C g^-1. The highest electrochemical performance of the quaternary nanocomposite is associated with the synergistic/additional effect of PPy, Ni(OH)₂, GN, and Ag. The assembled supercapattery with Ag/GN@PPy-Ni(OH)₂ as a positive and activated carbon (AC) as a negative electrode displayed eminent energy density of 43.26 Wh kg^-1 with the associated power density of 750.00 W kg^-1 at a current density of 1.0 A g^-1. The cyclic stability of the supercapattery (Ag/GN@PPy-Ni(OH)₂//AC), comprising a battery-type electrode, displayed a high cyclic stability of 108.37% after 5500 cycles.

Correction to Pyramid-Shaped PEG-PCL-PEG Polymeric-Based Model Systems for Site-Specific Drug Delivery of Vancomycin with Enhance Antibacterial Efficacy

[This corrects the article DOI: 10.1021/acsomega.9b04064.].

SARS-CoV-2-on-Chip for Long COVID Management

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a "wicked evil" in this century due to its extended progression and huge human mortalities. Although the diagnosis of SARS-CoV-2 viral infection is made simple and practical by employing reverse transcription polymerase chain reaction (RT-PCR) investigation, the process is costly, complex, time-consuming, and requires experts for testing and the constraints of a laboratory. Therefore, these challenges have raised the paradigm of on-site portable biosensors on a single chip, which reduces human resources and enables remote access to minimize the overwhelming burden on the existing global healthcare sector. This article reviews the recent advancements in biosensors for long coronavirus disease (COVID) management using a multitude of devices, such as point-of-care biosensors and lab-on-chip biosensors. Furthermore, it details the shift in the paradigm of SARS-CoV-2-on-chip biosensors from the laboratory to on-site detection with intelligent and economical operation, representing near-future diagnostic technologies for public health emergency management.

Emergence of infectious diseases and role of advanced nanomaterials in point-of-care diagnostics: a review

Infectious outbreaks are the foremost global public health concern, challenging the current healthcare system, which claims millions of lives annually. The most crucial way to control an infectious outbreak is by early detection through point-of-care (POC) diagnostics. POC diagnostics are highly advantageous owing to the prompt diagnosis, which is economical, simple and highly efficient with remote access capabilities. In particular, utilization of nanomaterials to architect POC devices has enabled highly integrated and portable (compact) devices with enhanced efficiency. As such, this review will detail the factors influencing the emergence of infectious diseases and methods for fast and accurate detection, thus elucidating the underlying factors of these infections. Furthermore, it comprehensively highlights the importance of different nanomaterials in POCs to detect nucleic acid, whole pathogens, proteins and antibody detection systems. Finally, we summarize findings reported on nanomaterials based on advanced POCs such as lab-on-chip, lab-on-disc-devices, point-of-action and hospital-on-chip. To this end, we discuss the challenges, potential solutions, prospects of integrating internet-of-things, artificial intelligence, 5G communications and data clouding to achieve intelligent POCs.

Advances in Noble-Metal Nanoparticle-Based Fluorescence Detection of Organophosphorus Chemical Warfare Agents

Efficient and simple detection of chemical warfare agents (CWAs) is an essential step in minimizing the potentially lethal consequences of chemical weapons. CWAs are a family of organic chemicals that are used as chemical weapons because of their enormous severity and lethal effects when faced with unforeseen challenges. To stop the spread of CWAs, it is critical to develop a platform that detects them in a sensitive, timely, selective, and minimally invasive manner. Rapid advances in the demand for on-site sensors, metal nanoparticles, and biomarker identification for CWAs have made it possible to use fluorescence as a precise real-time and point-of-care (POCT) testing technique. For POCT-based applications, the new capabilities of micro- and nanomotors offer enormous prospects. In recent decades, significant progress has been made in the design of fluorescent sensors and the further development of noble metal nanoparticles for the detection of organophosphorus CWAs, as described in this review. Through this work, recent attempts to fabricate sensors that can detect organophosphorus CWAs through changes in their fluorescence properties have been summarized. Finally, an integrated outlook on how noble metal nanoparticles could be used to develop smart sensors for organophosphorus CWAs that communicate with and control electronic devices to monitor and improve the health of individuals.

Epidemiology, virology and clinical aspects of hantavirus infections: an overview

At the end of 2019 and 2020s, a wave of coronavirus disease 19 (COVID-19) epidemics worldwide has catalyzed a new era of 'communicable infectious diseases'. However, the world is not currently prepared to deal with the growing burden of COVID-19, with the unexpected arrival of Hantavirus infection heading to the next several healthcare emergencies in public. Hantavirus is a significant class of zoonotic pathogens of negative-sense single-stranded ribonucleic acid (RNA). Hemorrhagic renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS) are the two major clinical manifestations. Till date, there is no effective treatments or vaccines available, public awareness and precautionary measures can help to reduce the spread of hantavirus disease. In this study, we outline the epidemiology, virology, clinical aspects, and existing HFRS and HCPS management approaches. This review will give an understanding of virus-host interactions and will help for the early preparation and effective handling of further outbreaks in an ever-changing environment.

Advanced nanoengineered-customized point-of-care tools for prostate-specific antigen

Change in the level of human prostate-specific antigen (PSA) is a major element in the development and progression of prostate cancer (PCa). Most of the methodologies are currently restricted to their application in routine clinical screening due to the scarcity of adequate screening tools, false reading, long assay time, and cost. Innovative techniques and the integration of knowledge from a variety of domains, such as materials science and engineering, are needed to provide sustainable solutions. The convergence of precision point-of-care (POC) diagnostic techniques, which allow patients to respond in real time to changes in PSA levels, provides promising possibilities for quantitative and quantitative detection of PSA. This solution could be interesting and relevant for use in PCa diagnosis at the POC. The approaches enable low-cost real-time detection and are simple to integrate into user-friendly sensor devices. This review focuses on the investigations, prospects, and challenges associated with integrating engineering sciences with cancer biology to develop nanotechnology-based tools for PCa diagnosis. This article intends to encourage the development of new nanomaterials to construct high-performance POC devices for PCa detection. Finally, the review concludes with closing remarks and a perspective forecast.

Nano-enabled strategies to combat methicillin-resistant Staphylococcus aureus

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) has become a threat to global health because of limited treatments. MRSA infections are difficult to treat due to increasingly developing resistance in combination with protective biofilms of Staphylococcus aureus (S. aureus). Nanotechnology-based research revealed that effective MRSA treatments could be achieved through targeted nanoparticles (NPs) that withstand biological films and drug resistance. Thus, the principal aim towards improving MRSA treatment is to advance drug delivery tools, which successfully address the delivery-related problems. These potential delivery tools would also carry drugs to the desired sites of therapeutic action to overcome the adverse effects. This review focused on different types of nano-engineered carriers system for antimicrobial agents with improved therapeutic efficacy of entrapped drugs. The structural characteristics that play an essential role in the effectiveness of delivery systems have also been addressed with a description of recent scientific advances in antimicrobial treatment, emphasizing challenges in MRSA treatments. Consequently, existing gaps in the literature are highlighted, and reported contradictions are identified, allowing for the development of roadmaps for future research.

Rationally engineered nanosensors: A novel strategy for the detection of heavy metal ions in the environment

Heavy metal ions (HMIs) have been mainly originated from natural and anthropogenic agents. It has become one of biggest societal issues due to their recognised accumulative and toxic effects in the environment as well as biological media. Key measures are required to reduce the risks posed by toxic metal pollutants existing in the environment. The increased research activities of HMIs detection, and use of technologies based on electrochemical detection that combine with engineered nanomaterials, is a key promising and innovative strategy that can potentially confine heavy metal poisoning. Deep understanding of the characteristics of the physicochemical properties of nanomaterials is highly required. It is also important to interpret the parameters at the nano-bio interface level that merely affect cross-interactions between nanomaterials and HMIs. Therefore, the authors outlined the state-of-the-art techniques that used engineeringly developed nanomaterials to detect HMIs in the environment. The possible novel applications of extensive and relatively low-cost HMIs monitoring and detection are discussed on the basis of these strengths. Finally, it is concluded by providing gist on acquaintance with facts in the present-day scenario along with highlighting areas to explore the strategies to overcome the current limitations for practical applications is useful in further generations of nano-world.

Antimicrobial properties of multifunctional polypyrrole-cobalt oxide-silver nanocomposite against pathogenic bacteria and parasite

BACKGROUND

Conducting polymer based nanocomposites are known to be effective against pathogens. Herein, we report the antimicrobial properties of multifunctional polypyrrole-cobalt oxide-silver nanocomposite (PPy-Co₃O₄-AgNPs) for the first time. Antibacterial activities were tested against multi-drug-resistant Gram-negative Escherichia coli (E. coli) and Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) bacteria, while antiamoebic effects were assessed against opportunistic protist Acanthamoeba castellanii (A. castellanii).

RESULTS

The ternary nanocomposite containing conducting polymer polypyrrole, cobalt oxide, and silver nanoparticles showed potent antimicrobial effects against these pathogens. The antibacterial assay showed that PPy-Co₃O₄-AgNPs exhibited significant bactericidal activity against neuropathogenic E. coli K1 at only 8 μg/mL as compared to individual components of the nanocomposite, whereas a 70 % inhibition of A. castellanii viability was observed at 50 μg/mL. Moreover, PPy-Co₃O₄-AgNPs were found to have minimal cytotoxicity against human keratinocytes HaCaT cells in vitro even at higher concentration (50 μg/mL), and also reduced the microbes-mediated cytopathogenicity against host cells.

CONCLUSION

These results demonstrate that PPy-Co₃O₄-AgNPs hold promise in the development of novel antimicrobial nanomaterials for biomedical applications.

KEY POINTS

•Synthesis of polypyrrole-cobalt oxide-silver (PPy-Co₃O₄-AgNPs) nanocomposite. •Antimicrobial activity of nanocomposite. •PPy-Co₃O₄-AgNPs hold promise for biomedical applications.

The emerging role of immune checkpoint inhibitors in the treatment of triple-negative breast cancer

Triple-negative breast cancers (TNBCs) form a heterogeneous group of breast carcinomas that lack expression of estrogen receptor, progesterone receptor and epidermal growth factor receptor 2. In the past decade, immune checkpoint inhibitors (ICIs) have revolutionized the arena of cancer immunotherapy. Early results are now accumulating from trials involving the treatment of TNBCs with radical ICIs therapies, including combinational therapies that include ICI technologies. In this review, we provide a broad overview of the progress of immunotherapy-based treatments and discuss future opportunities for their use in TNBC.

Hydrothermally Assisted Synthesis of Porous Polyaniline@Carbon Nanotubes-Manganese Dioxide Ternary Composite for Potential Application in Supercapattery

In this study, ternary composites of polyaniline (PANI) with manganese dioxide (MnO₂) nanorods and carbon nanotubes (CNTs) were prepared by employing a hydrothermal methodology and in-situ oxidative polymerization of aniline. The morphological analysis by scanning electron microscopy showed that the MnO₂ possessed nanorod like structures in its pristine form, while in the ternary PANI@CNT/MnO₂ composite, coating of PANI over CNT/MnO₂, rods/tubes were evidently seen. The structural analysis by X-ray diffraction and X-ray photoelectron spectroscopy showed peaks corresponding to MnO₂, PANI and CNT, which suggested efficacy of the synthesis methodology. The electrochemical performance in contrast to individual components revealed the enhanced performance of PANI@CNT/MnO₂ composite due to the synergistic/additional effect of PANI, CNT and MnO₂ compared to pure MnO₂, PANI and PANI@CNT. The PANI@CNT/MnO₂ ternary composite exhibited an excellent specific capacity of 143.26 C g^-1 at a scan rate of 3 mV s^-1. The cyclic stability of the supercapattery (PANI@CNT/MnO₂/activated carbon)-consisting of a battery type electrode-demonstrated a gradual increase in specific capacity with continuous charge-discharge over ~1000 cycles and showed a cyclic stability of 119% compared to its initial value after 3500 cycles.

Cobalt Oxide Nanograins and Silver Nanoparticles Decorated Fibrous Polyaniline Nanocomposite as Battery-Type Electrode for High Performance Supercapattery

In this study, silver (Ag) and cobalt oxide (Co₃O₄) decorated polyaniline (PANI) fibers were prepared by the combination of in-situ aniline oxidative polymerization and the hydrothermal methodology. The morphology of the prepared Ag/Co₃O₄@PANI ternary nanocomposite was studied by scanning electron microscopy and transmission electron microscopy, while the structural studies were carried out by X-ray diffraction and X-ray photoelectron spectroscopy. The morphological characterization revealed fibrous shaped PANI, coated with Ag and Co₃O₄ nanograins, while the structural studies revealed high purity, good crystallinity, and slight interactions among the constituents of the Ag/Co₃O₄@PANI ternary nanocomposite. The electrochemical performance studies revealed the enhanced performance of the Ag/Co₃O₄@PANI nanocomposite due to the synergistic/additional effect of Ag, Co₃O₄ and PANI compared to pure PANI and Co₃O₄@PANI. The addition of the Ag and Co₃O₄ provided an extended site for faradaic reactions leading to the high specific capacity. The Ag/Co₃O₄@PANI ternary nanocomposite exhibited an excellent specific capacity of 262.62 C g⁻¹ at a scan rate of 3 mV s⁻¹. The maximum energy and power density were found to be 14.01 Wh kg⁻¹ and 165.00 W kg⁻¹, respectively. The cyclic stability of supercapattery (Ag/Co₃O₄@PANI//activated carbon) consisting of a battery type electrode demonstrated a gradual increase in specific capacity with a continuous charge–discharge cycle until ~1000 cycles, then remained stable until 2500 cycles and later started decreasing, thereby showing the cyclic stability of 121.03% of its initial value after 3500 cycles.

A novel highly efficient and ultrasensitive electrochemical detection of toxic mercury (II) ions in canned tuna fish and tap water based on a copper metal-organic framework

Invisible mercury ion is an incredibly toxic pollutant to the atmosphere. Thus a quick and sensitive detection method is of considerable importance for toxicological assessment, environmental protection and human health. A novel electrochemical sensing system has been developed for the detection of mercury (Hg²⁺) ions in canned tuna fish and tap water. The sensing platform was developed on the cubic copper-metal-organic framework (Cu-MOF) based nanoparticles. Cu-MOF has a porous architecture with a large, unique surface area that is favorable for mercury ions adsorption and preconcentration. The electrochemical properties of Cu-MOF nanoparticles modified electrode were investigated. Differential pulse voltammetry (DPV) and cyclic voltammetry (CV) were applied for the detection of mercury in 0.1 M phosphate buffer (PB) at pH 9 under ambient conditions. Under optimized conditions, the limit of detection (LOD) for Hg²⁺ is around 0.0633 nM with a linear range of 0.1-50 nM. Cu-MOF nanoparticles were successfully applied to the analysis of mercury ions in canned tuna fish and tap water. The developed sensor demonstrated satisfactory anti-interference, reproducibility, reliability, repeatability and applicability for the detection of mercury ions. This proof of principle serves as a steppingstone towards promoting ultrasensitive and precise assay for the detection of mercury.

Fabrication of 3D binder-free graphene NiO electrode for highly stable supercapattery

Electrochemical stability of energy storage devices is one of their major concerns. Polymeric binders are generally used to enhance the stability of the electrode, but the electrochemical performance of the device is compromised due to the poor conductivity of the binders. Herein, 3D binder-free electrode based on nickel oxide deposited on graphene (G-NiO) was fabricated by a simple two-step method. First, graphene was deposited on nickel foam via atmospheric pressure chemical vapour deposition followed by electrodeposition of NiO. The structural and morphological analyses of the fabricated G-NiO electrode were conducted through Raman spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray spectroscopy (EDS). XRD and Raman results confirmed the successful growth of high-quality graphene on nickel foam. FESEM images revealed the sheet and urchin-like morphology of the graphene and NiO, respectively. The electrochemical performance of the fabricated electrode was evaluated through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) in aqueous solution at room temperature. The G-NiO binder-free electrode exhibited a specific capacity of ≈ 243 C g-1 at 3 mV s-1 in a three-electrode cell. A two-electrode configuration of G-NiO//activated charcoal was fabricated to form a hybrid device (supercapattery) that operated in a stable potential window of 1.4 V. The energy density and power density of the asymmetric device measured at a current density of 0.2 A g-1 were estimated to be 47.3 W h kg-1 and 140 W kg-1, respectively. Additionally, the fabricated supercapattery showed high cyclic stability with 98.7% retention of specific capacity after 5,000 cycles. Thus, the proposed fabrication technique is highly suitable for large scale production of highly stable and binder-free electrodes for electrochemical energy storage devices.

Pyramid-Shaped PEG-PCL-PEG Polymeric-Based Model Systems for Site-Specific Drug Delivery of Vancomycin with Enhance Antibacterial Efficacy

Antibacterial resistance remains a major global problem due to frequent prescriptions, leading to significant toxicities. To overcome the limitations of antibiotic therapy, it is highly desirable to provide site-specific delivery of drugs with controlled release. Inspired by the biocompatible, biodegradable, and site-specific mimicking behavior of poly(ethylene glycol) (PEG) and poly(caprolactone) (PCL), we developed vancomycin-PEG-PCL-PEG conjugates to maximize the pharmacological effects and minimize the side effects. Drug-loaded vancomycin-PEG-PCL-PEG conjugates are influenced by size, shape, surface area, encapsulation efficiency, in vitro drug release, hemolysis assay, cytotoxicity, and antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and bacterial kill kinetics. The results demonstrated that vancomycin (VCM) release from PEG-PCL-PEG triblock revealed a biphasic manner. Hemolysis assay showed the nonprescription nature of VCM-PEG-PCL-PEG. Cytotoxicity studies confirmed the biocompatibility of VCM-PEG-PCL-PEG. The in vitro antibacterial results showed enhance activity with minimum inhibitory concentration compared to bare VCM. Molecular dynamics simulation study revealed that binding between VCM and PEG-PCL-PEG by hydrophobic interactions offers molecular encapsulation and steric barrier to drug degradation. This newly developed therapeutic delivery system can offer to enhance activity and delivery VCM against MRSA.

Role of immune checkpoint inhibitors in the revolutionization of advanced melanoma care

Melanoma cancer is an important public health concern owing to its prevalence, high recurrence risk, treatment failures and immunosuppressive abilities. Prolonged immune system activation is the main objective of immune checkpoint inhibitors (ICIs) therapies directed against melanoma cancer. Despite the staggering advancements in approved ICIs therapy effectiveness, immune-related adverse events (imAEs) and therapeutic resistance has limited its wide application. Thus, there is a need to establish biomarkers that predict the response to ICIs and imAEs. In this review article, we provide an in-depth understanding of the role of tolerance, immunity, and immunosuppression in antitumor immune response regulation, together with ongoing clinical therapy and suggested biomarkers. These attainments advise that approved ICIs provide a novel approach to durable and prolonged response in cancer patients and will aid in the reduction of treatment cost and duration and enhance patient recovery.

Low-potential immunosensor-based detection of the vascular growth factor 165 (VEGF165) using the nanocomposite platform of cobalt metal–organic framework

The vascular endothelial growth factor 165 (VEGF₁₆₅) is a quintessential biomarker in cancers. An easy and precise tool for the early detection of malignancies is required for rapid care and metastasis prevention. Cobalt-based metal–organic framework (Co-BTC-GO-MOF) nanoparticles have been used as a signal carrier for the anti-VEGF₁₆₅ signaling antibody. Cobalt-based MOF was synthesized using cobalt (Co), benzene-1,3,5-tricarboxylate (BTC), and graphene oxide (GO) applying a hydrothermal method. Structure, compositions, size and morphology of the qualified sensor are determined by using distinctive analytical techniques. The Co-MOF nanoparticles are found to be thermostable, as revealed by thermal stability assay. The strategy utilises an impedimetric and differential pulse voltammetry (DPV) techniques in the presence of the [Fe(CN)₆]^3−/4− redox system. Compared to earlier results, this assay resulted in higher sensitivity with the limit of detection (LOD) found to be 5.23 pM in a 0.01 M buffer solution of pH 7.4 using linear scale voltammetry at room temperature. The resulting Co-BTC-GO-MOF immunosensor shows high responsiveness and selectivity in detecting VEGF₁₆₅ in real-time serum samples of cancer patients. The electrochemical performance studies confirm that the intended proposed immunosensor could pave the way for the future advancement of high-performance, sensitive, reproducible and robust immunosensors for the cost-effective and initial phase detection of cancer in the future.

The vascular endothelial growth factor 165 (VEGF₁₆₅) is a quintessential biomarker in cancers.

Ultrasonication-assisted synthesis of novel strontium based mixed phase structures for supercapattery devices

An upsurge in sustainable energy demands has ultimately made supercapattery one of the important choice for energy storage, owing to highly advantageous energy density and long life span. In this work, novel strontium based mixed phased nanostructures were synthesized by using probe sonicator with sonication power 500 W at frequency of 20 kHz. The synthesized material was subsequently calcined at different temperature ranging from 200 to 800 °C. Structural and morphological analysis of the synthesized materials reveals the formation of mixed particle and rod like nanostructures with multiple crystal phases of strontium oxides and carbonates. Crystallinity, grain size and morphology of grown nanomaterials significantly improved with the increase of calcination temperature due to sufficient particle growth and low agglomeration. The electrochemical performance analysis confirms the redox activeness of the Sr-based electrode materials. Material calcined at 600 °C show high specific capacitance of 350 F g^-1 and specific capacity of 175 C g^-1 at current density of 0.3 A g^-1 due to less particle agglomeration, good charge transfer and more contribution of electrochemical active sites for redox reactions. In addition, the developed supercapattery of Sr-based nanomaterials//activated carbon demonstrated high performance with maximum energy density of 21.8 Wh kg^-1 and an excellent power density of 2400 W kg^-1 for the lower and higher current densities. Furthermore, the supercapattery retain 87% of its capacity after continuous 3000 charge/discharge cycles. The device characteristics were further investigated by analyzing the capacitive and diffusion controlled contributions. The versatile strategy of developing mixed phased nanomaterials pave the way to synthesize other transition metal based nanomaterials with superior electrochemical performance for hybrid energy storage devices.

Enhancing the Efficiency of a Dye-Sensitized Solar Cell Based on a Metal Oxide Nanocomposite Gel Polymer Electrolyte

To overcome the critical limitations of liquid-electrolyte-based dye-sensitized solar cells, quasi-solid-state electrolytes have been explored as a means of addressing long-term device stability, albeit with comparatively low ionic conductivities and device performances. Although metal oxide additives have been shown to augment ionic conductivity, their propensity to aggregate into large crystalline particles upon high-heat annealing hinders their full potential in quasi-solid-state electrolytes. In this work, sonochemical processing has been successfully applied to generate fine Co₃O₄ nanoparticles that are highly dispersible in a PAN:P(VP-co-VAc) polymer-blended gel electrolyte, even after calcination. An optimized nanocomposite gel polymer electrolyte containing 3 wt % sonicated Co₃O₄ nanoparticles (PVVA-3) delivers the highest ionic conductivity (4.62 × 10^-3 S cm^-1) of the series. This property is accompanied by a 51% enhancement in the apparent diffusion coefficient of triiodide versus both unmodified and unsonicated electrolyte samples. The dye-sensitized solar cell based on PVVA-3 displays a power conversion efficiency of 6.46% under AM1.5 G, 100 mW cm^-2. By identifying the optimal loading of sonochemically processed nanoparticles, we are able to generate a homogenous extended particle network that effectively mobilizes redox-active species through a highly amorphous host matrix. This effect is manifested in a selective 51% enhancement in photocurrent density (J_SC = 16.2 mA cm^-2) and a lowered barrier to N719 dye regeneration (R_CT = 193 Ω) versus an unmodified solar cell. To the best of our knowledge, this work represents the highest known efficiency to date for dye-sensitized solar cells based on a sonicated Co₃O₄-modified gel polymer electrolyte. Sonochemical processing, when applied in this manner, has the potential to make meaningful contributions toward the ongoing mission to achieve the widespread exploitation of stable and low-cost dye-sensitized solar cells.

Cobalt nanoparticles as novel nanotherapeutics against Acanthamoeba castellanii

Background

Species of Acanthamoeba are facultative pathogens which can cause sight threatening Acanthamoeba keratitis and a rare but deadly brain infection, granulomatous amoebic encephalitis. Due to conversion of Acanthamoeba trophozoites to resistant cyst stage, most drugs are found to be ineffective at preventing recurrence of infection. This study was designed to test the antiacanthamoebic effects of different cobalt nanoparticles (CoNPs) against trophozoites and cysts, as well as parasite-mediated host cell cytotoxicity.

Methods

Three different varieties of CoNPs were synthesized by utilizing hydrothermal and ultrasonication methods and were thoroughly characterized by X-ray diffraction and field emission scanning electron microscopy. Amoebicidal, encystation, excystation, and host cell cytopathogenicity assays were conducted to study the antiacanthamoebic effects of CoNPs.

Results

The results of the antimicrobial evaluation revealed that cobalt phosphate Co₃(PO₄)₂ hexagonal microflakes, and 100 nm large cobalt hydroxide (Co(OH)₂) nanoflakes showed potent amoebicidal activity at 100 and 10 µg/ml against Acanthamoeba castellanii as compared to granular cobalt oxide (Co₃O₄) of size 35–40 nm. Furthermore, encystation and excystation assays also showed consistent inhibition at 100 µg/ml. CoNPs also inhibited amoebae-mediated host cell cytotoxicity as determined by lactate dehydrogenase release without causing significant damage to human cells when treated alone.

Conclusions

To our knowledge, these findings determined, for the first time, the effects of composition, size and morphology of CoNPs against A. castellanii. Co₃(PO₄)₂ hexagonal microflakes showed the most promising antiamoebic effects as compared to Co(OH)₂ nanoflakes and granular Co₃O₄. The results reported in the present study hold potential for the development of antiamoebic nanomedicine.

Density functional theory simulation of cobalt oxide aggregation and facile synthesis of a cobalt oxide, gold and multiwalled carbon nanotube based ternary composite for a high performance supercapattery

A novel ternary composite consisting of cobalt oxide (Co₃O₄) nanoparticles (NPs) grown on multiwalled carbon nanotubes (MWCNTs) and mixed with gold (Au) NPs is synthesized by a single step hydrothermal route.

Pressure flow pattern of varicocele veins and its correlation with testicular blood flow and semen parameters

The pressure pattern in varicocele veins of infertile patients and its correlation with semen quality and testicular blood flow was determined. Consecutive patients at andro-urology clinic of a teaching hospital undergoing microsurgical varicocelectomy were included. Their semen quality and testicular blood flow were determined. Peak systolic velocity (PSV) and resistive index (RI) of subcapsular and intraparenchymal branches of testicular artery were noted by colour Doppler ultrasonography. During surgery before ligation of varicocele veins, intravenous pressures of internal spermatic (ISV) and external spermatic (ESV) veins were determined at baseline and after Valsalva manoeuvre. Thirty patients, 20-45 years old, were evaluated. Baseline pressure for maximum dilated ISV (A), less dilated ISV (B) and ESV was 15.93 ± 6.34, 12.38 ± 4.60 and 12.92 ± 5.65 mm. Hg, respectively, which increased after Valsalva by 104.4%, 116.2% and 38.22% respectively. Correlation (r = -.71; p < .05) was appreciated between percentage increase in pressure of ISV B with PSV of intraparenchymal testicular arteries and progressive motility (r = -.759; p < .05), nonprogressive motility (r = -.738; p < .05) and morphology (r = -.653; p = .07) of spermatozoa. In conclusion, ISV develops higher pressure on Valsalva as compared to ESV and has correlation with semen quality and testicular blood flow.

An Approach to Solid-State Electrical Double Layer Capacitors Fabricated with Graphene Oxide-Doped, Ionic Liquid-Based Solid Copolymer Electrolytes

Solid polymer electrolyte (SPE) composed of semi-crystalline poly (vinylidene fluoride-hexafluoropropylene) [P(VdF-HFP)] copolymer, 1-ethyl-3-methylimidazolium bis (trifluoromethyl sulphonyl) imide [EMI-BTI] and graphene oxide (GO) was prepared and its performance evaluated. The effects of GO nano-filler were investigated in terms of enhancement in ionic conductivity along with the electrochemical properties of its electrical double layer capacitors (EDLC). The GO-doped SPE shows improvement in ionic conductivity compared to the P(VdF-HFP)-[EMI-BTI] SPE system due to the existence of the abundant oxygen-containing functional group in GO that assists in the improvement of the ion mobility in the polymer matrix. The complexation of the materials in the SPE is confirmed in X-ray diffraction (XRD) and thermogravimetric analysis (TGA) studies. The electrochemical performance of EDLC fabricated with GO-doped SPE is examined using cyclic voltammetry and charge–discharge techniques. The maximum specific capacitance obtained is 29.6 F∙g⁻¹, which is observed at a scan rate of 3 mV/s in 6 wt % GO-doped, SPE-based EDLC. It also has excellent cyclic retention as it is able keep the performance of the EDLC at 94% even after 3000 cycles. These results suggest GO doped SPE plays a significant role in energy storage application.

Facile sonochemical synthesis of nanostructured NiO with different particle sizes and its electrochemical properties for supercapacitor application

In this work, we demonstrate the influence of nickel oxides with divergent particle sizes as the working electrodes for supercapacitor application. The nanostructured nickel oxide (NiO) is synthesized via facile sonochemical method, followed by calcination process. The crystallinity and surface purity of prepared samples are clearly examined by X-ray diffraction and Raman analysis. NiO crystallinity is significantly increased with increasing calcination temperatures. The surface analysis confirmed that the calcination at 250°C exhibited nanoclutser like NiO with average particle size of ∼6nm. While increasing the calcination temperature beyond 250°C, hexagonal shaped NiO is observed with enhanced particle sizes. The electrochemical performance confirmed the good redox behavior of NiO electrodes. Moreover, NiO with average particle size of ∼6nm exhibited high specific capacitance of 449F/g at a scan rate of 5mV/s compared to other samples with particle sizes of ∼21nm (323F/g) and ∼41nm (63F/g). This is due to the good ion transfer mechanism and effective electrochemical utilization of the working electrode.

Enhanced electrochemical performance of cobalt oxide nanocube intercalated reduced graphene oxide for supercapacitor application

We investigated different molar concentrations of cobalt precursor intercalated reduced graphene oxide (rGO) as possible electrode materials for supercapacitors.

Ultrahigh capacitance of amorphous nickel phosphate for asymmetric supercapacitor applications

This article presents the effect of different calcination temperatures on the structural, morphological and capacitance of nickel phosphate (Ni₃(PO₄)₂) as an electrode material for supercapacitor applications.