Advanced Functional Materials for Electrochemical and Biosensors.

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Ti3AlC2 MAX Phase Modified Screen-Printed Electrode for the Fabrication of Hydrazine Sensor.

Hydrazine is considered a powerful reducing agent and catalyst, showing diverse applications in agricultural industries, toxic degradation research, and wastewater management. Additionally, hydrazine can trigger some specific reactions when combined with suitable oxidants. Due to its highly polar nature, hydrazine can easily dissolve in alcohol, water, and various other polar solvents. Therefore, it can be extensively utilized in different areas of application and industries such as rocketry and various chemical applications. Despite its beneficial properties, hydrazine is unstable, posing significant risk due to its highly toxic nature. It is extremely hazardous to both human health and the environment. It can cause various illnesses and symptoms such as dizziness, temporary blindness, damage to the central nervous system, and even death when inhaled in sufficient quantities. Therefore, it is highly important to monitor the level of hydrazine to prevent its toxic and hazardous effects on human beings and the environment. In the present study, we discuss the simple fabrication of a disposable cost-effective and eco-friendly hydrazine sensor. We used a screen-printed carbon electrode, i.e., SPCE, as a base for the construction of a hydrazine sensor. The Ti3AlC2 MAX has been used as a suitable and efficient electrode material for the fabrication of disposable hydrazine sensors. We modified the active surface of the SPCE using a drop-casting approach. The resulting Ti3AlC2 MAX modified SPCE (Ti3AlC2@SPCE) has been utilized as an efficient and low-cost hydrazine sensor. Cyclic voltammetry, i.e., CV, and linear sweep voltammetry, viz., LSV, was employed as a sensing technique in this study. The optimization of pH and electrode material loading was conducted. The Ti3AlC2@SPCE exhibited excellent sensing performance toward hydrazine oxidation. A reasonable detection limit (0.01 µM) was achieved for hydrazine sensing. The fabricated sensor also demonstrated a reasonable linear range of 1-50 µM. This work provides the design and fabrication of simple disposable Ti3AlC2@SPCE as a suitable electrode for the determination of hydrazine using LSV technology.

Fabrication of an Azithromycin Sensor.

Azithromycin (AZY) is a well-known top-prioritized antibiotic and is used by humans in strong concentrations. However, the side effects of the AZY antibiotic may cause some serious and significant damage to humans and the environment. Thus, there is a need to develop effective and sensitive sensors to monitor accurate concentrations of AZY. In the last decade, electrochemistry-based sensors have received enormous attention from the scientific community because of their high sensitivity, selectivity, cost-effectiveness, fast response, rapid detection response, simple fabrication, and working principle. It is important to mention that electrochemical sensors rely on the properties of electrode modifiers. Hence, the selection of electrode materials is of great significance when designing and developing efficient and robust electrochemical sensors. In this study, we fabricated an AZY sensor by utilizing a molybdenum disulfide/titanium aluminum carbide (MoS2@Ti3AlC2) composite as the electrode material. The MoS2@Ti3AlC2 composite was synthesized via a simple sonication process. The synthesized MoS2@Ti3AlC2 composite was characterized using a powder X-ray diffraction (XRD) method to examine the phase purity and formation of the MoS2@Ti3AlC2 composite. Scanning electron microscopy (SEM) was used to study the surface morphological features of the prepared MoS2@Ti3AlC2 composite, whereas energy dispersive X-ray spectroscopy (EDAX) was adopted to determine the elemental composition of the prepared MoS2@Ti3AlC2 composite. The glassy carbon (GC) electrode was modified with the prepared MoS2@Ti3AlC2 composite and applied as the AZY sensor. The sensing performance of the MoS2@Ti3AlC2 composite-modified GC electrode was studied using linear sweep voltammetry. The sensor demonstrated excellent performance when determining AZY and showed a good detection limit of 0.009 µM with a sensitivity of 6.77 µA/µM.cm2.

Evolutionary insights on critically endangered Kashmir red deer or hangul (Cervus hanglu hanglu) through a mitogenomic lens.

Background: The Kashmir red deer or Hangul (Cervus hanglu hanglu) is the only Tarim red deer species endemic to India. With a current estimated population size of fewer than 200 individuals, this critically endangered species is confined to the greater Dachigam landscape in Jammu and Kashmir. Poaching, habitat loss and fragmentation, resource competition with livestock, and small population size are the major conservation challenges for this species. Methods: Blood sampling was conducted from two wild Hangul individuals during radio-collaring operations at Dachigam National Park, Kashmir in 2013 and 2020, respectively. Using next-generation sequencing approach, we sequenced the 16,351 bp long mitogenome of two wild-caught Hangul individuals (1 M:1 F at ~14× and ~10× coverage, respectively) from Dachigam National Park. Results: The annotated sequences were identical with an AT-rich composition, including 13 protein-coding genes (11,354 bp), 22 tRNA genes (1,515 bp), two ribosomal genes (2,526 bp) and a non-coding control region (917 bp) in a conserved order like other red deer species. Bayesian phylogenetic reconstruction of the red deer complex revealed two major groups: the elaphoid and the wapitoid clades. Hangul formed a distinct clade with its other subspecies C. hanglu yarkandensis and is sister to the Hungarian red deer (C. elaphus hippelaphus). Divergence time analyses suggested that the Tarim deer species group separated ~1.55 Mya from their common ancestors and Hangul diverged ~0.75 Mya from closely related C. yarkandensis, corroborating with the known paleobiogeographic events related to refugia during glaciations in the Pleistocene era. This study provides baseline information on Hangul mitogenome for further research on phylogeography and other population parameters and helps in developing suitable conservation plans for this species.

Titanium Carbide (Ti3C2Tx) MXene as Efficient Electron/Hole Transport Material for Perovskite Solar Cells and Electrode Material for Electrochemical Biosensors/Non-Biosensors Applications.

Recently, two-dimensional (2D) MXenes materials have received enormous attention because of their excellent physiochemical properties such as high carrier mobility, metallic electrical conductivity, mechanical properties, transparency, and tunable work function. MXenes play a significant role as additives, charge transfer layers, and conductive electrodes for optoelectronic applications. Particularly, titanium carbide (Ti3C2Tx) MXene demonstrates excellent optoelectronic features, tunable work function, good electron affinity, and high conductivity. The Ti3C2Tx has been widely used as electron transport (ETL) or hole transport layers (HTL) in the development of perovskite solar cells (PSCs). Additionally, Ti3C2Tx has excellent electrochemical properties and has been widely explored as sensing material for the development of electrochemical biosensors. In this review article, we have summarized the recent advances in the development of the PSCs using Ti3C2Tx MXene as ETL and HTL. We have also compiled the recent progress in the fabrication of biosensors using Ti3C2Tx-based electrode materials. We believed that the present mini review article would be useful to provide a deep understanding, and comprehensive insight into the research status.

Potential of Natural Phenolic Compounds as Antimicrobial Agents against Multidrug-Resistant Staphylococcus aureus in Chicken Meat.

Staphylococcus aureus is one of the most widespread foodborne bacteria that cause high morbidity, mortality, and economic loss, primarily if foodborne diseases are caused by pathogenic and multidrug-resistant (MDR) strains. This study aimed to determine the prevalence of S. aureus in chicken meat in Egyptian markets. Thus, this study might be the first to assess the efficiency of different natural phenolic compounds as novel antibacterial agents against MDR S. aureus pathogens isolated from raw chicken meat in the Egyptian market. The incidence and quantification of pathogenic S. aureus were detected in retail raw chicken meat parts (breast, thigh, fillet, and giblets). In total, 73 out of 80 (91.3%) of the chicken meat parts were contaminated, with S. aureus as the only species isolated. Of the 192 identified S. aureus isolates, 143 were coagulase-positive S. aureus and 117 isolates were MDR (81.8%, 117/143). Twenty-two antibiotic resistance profile patterns were detected. One strain was randomly selected from each pattern to further analyze virulence and resistance genes. Extracted DNA was assessed for the presence of antibiotic-resistance genes, i.e., vancomycin-resistance (vanA), aminoglycosides-resistance (aacA-aphD), apramycin-resistance (apmA), and methicillin-resistance (mecA), penicillin-resistance (blaZ), and virulence genes staphylococcal enterotoxins (sea and seb), Panton-Valentine leucocidin (pvl), clumping factor A (clfA), and toxic shock syndrome toxin (tst). Clustering analyses revealed that six S. aureus strains harbored the most virulence and resistance genes. The activity of hydroquinone was significantly higher than thymol, carvacrol, eugenol, and protocatechuic acid. Therefore, phenolic compounds, particularly hydroquinone, could potentially alternate with conventional antibiotics against the pathogenic MDR S. aureus inhabiting raw chicken meat. Hence, this study indicates that urgent interventions are necessary to improve hygiene for safer meat in Egyptian markets. Moreover, hydroquinone could be a natural phenolic compound for inhibiting foodborne pathogens.

Antimicrobial peptide moricin induces ROS mediated caspase-dependent apoptosis in human triple-negative breast cancer via suppression of notch pathway.

BACKGROUND: Breast cancer is the world's most prevalent cancer among women. Microorganisms have been the richest source of antibiotics as well as anticancer drugs. Moricin peptides have shown antibacterial properties; however, the anticancer potential and mechanistic insights into moricin peptide-induced cancer cell death have not yet been explored. METHODS: An investigation through in silico analysis, analytical methods (Reverse Phase-High Performance Liquid Chromatography (RP-HPLC), mass spectroscopy (MS), circular dichroism (CD), and in vitro studies, has been carried out to delineate the mechanism(s) of moricin-induced cancer cell death. An in-silico analysis was performed to predict the anticancer potential of moricin in cancer cells using Anti CP and ACP servers based on a support vector machine (SVM). Molecular docking was performed to predict the binding interaction between moricin and peptide-related cancer signaling pathway(s) through the HawkDOCK web server. Further, in vitro anticancer activity of moricin was performed against MDA-MB-231 cells. RESULTS: In silico observation revealed that moricin is a potential anticancer peptide, and protein-protein docking showed a strong binding interaction between moricin and signaling proteins. CD showed a predominant helical structure of moricin, and the MS result determined the observed molecular weight of moricin is 4544 Da. An in vitro study showed that moricin exposure to MDA-MB-231 cells caused dose dependent inhibition of cell viability with a high generation of reactive oxygen species (ROS). Molecular study revealed that moricin exposure caused downregulation in the expression of Notch-1, NF-ƙB and Bcl2 proteins while upregulating p53, Bax, caspase 3, and caspase 9, which results in caspase-dependent cell death in MDA-MB-231 cells. CONCLUSIONS: In conclusion, this study reveals the anticancer potential and underlying mechanism of moricin peptide-induced cell death in triple negative cancer cells, which could be used in the development of an anticancer drug.

Acute myocardial infarction after a negative Dobutamine stress echocardiogram in a patient with end-stage liver disease.

Dobutamine stress echocardiogram (DSE) is generally a safe and reliable test for detection of myocardial ischaemia. We report the case of a 43-year-old male with end-stage liver disease (ESLD), who underwent DSE as part of workup for liver transplantation. Although the patient had an uneventful negative DSE, within 45 minutes he developed inferior ST-segment elevation myocardial infarction (STEMI). His coronary angiography showed severe 2-vessel coronary artery disease, which was treated with percutaneous coronary intervention (PCI) with implantation of drug-eluting stents (DES). Acute coronary syndrome (ACS) after a normal DSE has previously been reported in the literature. We describe one such case, with added complexity of managing an ACS in a patient with high bleeding risk. Our case is unique in reporting a STEMI after a negative DSE in a liver transplant recipient. Increased physician awareness of potential complications of DSE is essential to allow timely recognition and management.

Numerical Simulation and Experimental Study of Methyl Ammonium Bismuth Iodide Absorber Layer Based Lead Free Perovskite Solar Cells.

In the past few years, there has been a significant increase in the development and production of perovskite or perovskite-like materials that do not contain lead (Pb) for the purpose of constructing solar cells. The development and testing of lead-free perovskite-like structures for solar cells is crucial. In this study, we used the solar cell capacitance software (SCAPS) to simulate perovskite solar cells based on methyl ammonium bismuth iodide (MA3 Bi2 I9 ). The electron-transport layer, hole-transport layer, and absorber layer thickness were optimized using SCAPS. The simulated perovskite solar cells (FTO/TiO2 /MA3 Bi2 I9 /spiro-OMeTAD/Au) performed well with a power conversion efficiency of 14.07 % and a reasonable open circuit voltage of 1.34 V, using the optimized conditions determined by SCAPS. Additionally, we conducted experiments to fabricate perovskite solar cells under controlled humidity, which showed a power conversion efficiency of 1.31 %.

Improved photovoltaic performance of Pb-free AgBi2I7 based photovoltaics.

Hybrid perovskites based on bismuth are good candidates for developing lead-free and air-stable photovoltaics, but they have historically been constrained by poor surface morphologies and large band-gap energies. Monovalent silver cations are incorporated into iodobismuthates as part of a novel materials processing method to fabricate improved bismuth-based thin-film photovoltaic absorbers. However, a number of fundamental characteristics prevented them from achieving better efficiency. We examine bismuth iodide perovskite made of silver with improvements in surface morphology and a narrow band gap, and we achieve high power conversion efficiency. AgBi2I7 perovskite was used in the fabrication of PSCs as a material for light absorption, and its optoelectronic proficiencies were also studied. We reduced the band gap to 1.89 eV and achieved a maximum power conversion efficiency of 0.96% using the solvent engineering approach. Additionally, simulation studies verified an efficiency of 13.26% by using AgBi2I7 as a light absorber perovskite material.

Mechanochemical Synthesis of Lead-Free Perovskite-Like MA3 Bi2 I9 for Photo-Catalytic Hydrogen Production.

In this study, a highly air stable and eco-friendly methyl ammonium bismuth iodide (MA3 Bi2 I9 ) perovskite-like material has been prepared. After physiochemical characterizations, the synthesized MA3 Bi2 I9 was utilized as photo-catalyst towards hydrogen production. It is important to design and synthesize lead (Pb)-free perovskite-like material (MA3 Bi2 I9 ) for photo-catalytic hydrogen-production applications. The synthesized MA3 Bi2 I9 exhibits excellent photo-catalytic hydrogen generation with a production rate of 11.43 µmolg-1 h-1 . In the presence of a platinum co-catalyst, the hydrogen production rate further increases to 172.44 µmolg-1 h-1 . The MA3 Bi2 I9 photo-catalyst also demonstrates excellent cyclic stability.

Numerical Simulation of NH3(CH2)2NH3MnCl4 Based Pb-Free Perovskite Solar Cells Via SCAPS-1D.

Recently, the design and fabrication of lead (Pb)-free perovskite or perovskite-like materials have received great interest for the development of perovskite solar cells (PSCs). Manganese (Mn) is a less toxic element, which may be an alternative to Pb. In this work, we explored the role of NH3(CH2)2NH3MnCl4 perovskite as a light absorber layer via SCAPS-1D. A Pb-free PSC device (FTO/TiO2/NH3(CH2)2NH3MnCl4/spiro-OMeTAD/Au) was simulated via SCAPS-1D software. The simulated Pb-free PSCs (FTO/TiO2/NH3(CH2)2NH3MnCl4/spiro-OMeTAD/Au) showed decent power conversion efficiency (PCE) of 20.19%. Further, the impact of the thickness of absorber (NH3(CH2)2NH3MnCl4), electron transport (TiO2), and hole-transport (spiro-OMeTAD) layers were also investigated. Subsequently, various electron transport layers (ETLs) were also introduced to investigate the role of ETL. In further studies, an NH3(CH2)2NH3MnCl4-based PSC device (FTO/TiO2/NH3(CH2)2NH3MnCl4/spiro-OMeTAD/Au) was also developed (humidity = ~30-40%). The fabricated PSCs displayed an open circuit voltage (Voc) of 510 mV with a PCE of 0.12%.

Fabrication of CeO2/GCE for Electrochemical Sensing of Hydroquinone.

Hydroquinone is a widely used derivative of phenol which has a negative influence on human beings and the environment. The determination of the accurate amount of hydroquinone is of great importance. Recently, the fabrication of an electrochemical sensing device has received enormous attention. In this study, we reported on the facile synthesis of cerium dioxide (CeO2) nanoparticles (NPs). The CeO2 NPs were synthesized using cerium nitrate hexahydrate as a precursor. For determining the physicochemical properties of synthesized CeO2 NPs, various advanced techniques, viz., powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS), were studied. Further, these synthesized CeO2 NPs were used for the modification of a glassy carbon electrode (CeO2/GCE), which was utilized for the sensing of hydroquinone (HQ). A decent detection limit of 0.9 µM with a sensitivity of 0.41 µA/µM cm2 was exhibited by the modified electrode (CeO2/GCE). The CeO2/GCE also exhibited good stability, selectivity, and repeatability towards the determination of HQ.

Design and Fabrication of α-MnO2-Nanorods-Modified Glassy-Carbon-Electrode-Based Serotonin Sensor.

Serotonin is a very important monoamine neurotransmitter, which takes part in biological and psychological processes. In the present scenario, design and fabrication of a serotonin electrochemical sensor is of great significance. In this study, we have synthesized α-MnO2 via a hydrothermal synthesis method using potassium permanganate as a precursor. The physiochemical properties, such as structural and phase-purity of the prepared α-MnO2, were investigated by various characterization techniques and methods (powder X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy). Furthermore, the serotonin sensor was fabricated using α-MnO2 as an electrode modifier or electro-catalyst. The bare glassy carbon electrode (GCE) was adopted as a working substrate, and its active carbon surface was modified with the synthesized α-MnO2. This modified GCE (α-MnO2/GCE = MGCE) was explored as a serotonin sensor. The electrochemical investigations showed that the MGCE has excellent electro-catalytic properties towards determination of serotonin. The MGCE exhibits an excellent detection limit (DL) of 0.14 µM, along with good sensitivity of 2.41 µAµM-1 cm-2. The MGCE also demonstrated excellent selectivity for determination of serotonin in the presence of various electro-active/interfering molecules. The MGCE also exhibits good cyclic repeatability, stability, and storage stability.

Fabrication of Nitrogen-Doped Reduced Graphene Oxide Modified Screen Printed Carbon Electrode (N-rGO/SPCE) as Hydrogen Peroxide Sensor.

In recent years, the electrochemical sensing approach has attracted electrochemists because of its excellent detection process, simplicity, high sensitivity, cost-effectiveness, and high selectivity. In this study, we prepared nitrogen doped reduced graphene oxide (N-rGO) and characterized it using various advanced techniques such as XRD, SEM, EDX, Raman, and XPS. Furthermore, we modified the active surface of a screen printed carbon electrode (SPCE) via the drop-casting of N-rGO. This modified electrode (N-rGO/SPCE) exhibited an excellent detection limit (LOD) of 0.83 µM with a decent sensitivity of 4.34 µAµM-1cm-2 for the detection of hydrogen peroxide (H2O2). In addition, N-rGO/SPCE also showed excellent selectivity, repeatability, and stability for the sensing of H2O2. Real sample investigations were also carried out that showed decent recovery.

Fabrication of defective graphene oxide for efficient hydrogen production and enhanced 4-nitro-phenol reduction.

Hydrogen has been considered as one of the most promising alternative energy source to solve the future energy demands due to its high energy capacity and emission-free character. The generation of hydrogen from non-fossil sources is necessary for the sustainable development of human life on this planet. The hydrolysis of sodium borohydride can quickly produce a large amount of hydrogenin situand on-demand in the presence of the catalyst, which can be used as an alternative energy source. So, it is crucial to fabricate the highly efficient, robust, and economical catalyst for the production of hydrogen via hydrolysis of sodium borohydride. Herein, a facile and efficient approach for the synthesis of metal-functionalized reduced graphene oxide for the production of hydrogen at room temperature was used. Moreover, the synthesized catalyst has also been tested in the field of environmental catalysis for the reduction of toxic 4-nitrophenol to valuable 4-aminophenol in the presence of sodium borohydride. The enhanced activity of prepared metal-functionalized reduced graphene oxide is ascribed to a strong affinity between Fe-NXand reduced graphene oxide which facilitates electron transfer as well as synergistic effect. Overall, this work presents a crucial procedure for green chemistry reactions when a carbonaceous material is selected as a catalyst.

Synthesis and antimicrobial activities of some novel diastereoselective monocyclic cis-ß-lactams using 2-ethoxy carbonyl DCPN as a carboxylic acid activator.

A series of novel monocyclic cis-ß-lactams were prepared from phenoxyacetic acid as ketene source and imines derived from 1-chloro-3,4-dihydronaphthalene-2-carbaldehyde and respective amine using ethyl 4,5-dichloro-6-oxopyridazine-1(6H)-carboxylate (or 2-ethoxy carbonyl DCPN) as a carboxylic acid activator. This is the first time 2-ethoxy carbonyl DCPN has been used as an acid activator in synthesis of ß-lactams. The reaction was entirely diastereoselective leading to the formation cis-ß-lactam derivatives. These newly synthesized cis-ß-lactam were fully characterized by FT-IR, 1H NMR, 13C NMR, HRMS, CHNS and X-ray crystallography study. All this novel compound was also evaluated for their antibacterial and antifungal activities against certain strains of Gram-positive bacteria, Gram-negative bacteria and fungi. These compounds displayed moderate activity against using bacterial and fungal strains.

Anagallis arvensis Induces Apoptosis in HL-60 Cells Through ROS-Mediated Mitochondrial Pathway.

The present study was taken up to evaluate the apoptosis inducing ability of alcoholic extract of whole plant of Anagallis arvensis (AAE) in HL-60 cells. We observed time and concentration dependent decrease in cell viability after treatment with AAE. Fluorescent staining and scanning electron micrographs of treated HL-60 cells demonstrated chromatin condensation, nuclear fragmentation and formation of apoptotic blebs. There was a marked increase in hypodiploid population of cells as observed by cell cycle analysis. Annexin V-FITC/PI also depicted the presence of apoptotic cells. Anti-apoptotic protein Bcl-2 was observed to be decreased by 62% at 20 µg/ml concentration and a significant increase in ROS production up to 6.9-fold was observed in time dependent manner. In addition, alteration in mitochondrial membrane potential was observed, which was followed by cytochrome c release to cytoplasm. Activated levels of mitochondrial downstream pathway protein namely Caspase-3 and 9, were detected in treated HL-60 cells by colorimetric analysis. DNA ladder formation, a biochemical hallmark of apoptosis was also observed in treated HL-60 cells. The results of the present study support the apoptotic potential of AAE and probability of its promising role in development as effective anticancer agent against leukemia cells.

Design and fabrication of cost-effective and sensitive non-enzymatic hydrogen peroxide sensor using Co-doped δ-MnO2 flowers as electrode modifier.

The development of a cost-effective and highly sensitive hydrogen peroxide sensor is of great importance. Electrochemical sensing is considered the most sensitive technique for hydrogen peroxide detection. Herein, we reported a cost-effective and highly sensitive hydrogen peroxide sensor using Co-doped δ-MnO2 (Co@δ-MnO2) flower-modified screen-printed carbon electrode. The δ-MnO2 and Co@δ-MnO2 flowers were synthesized by employing a hydrothermal approach. Advanced techniques such as PXRD, SEM, FTIR, Raman, UV, EDX, BET, and TEM were utilized to confirm the formation of δ-MnO2 and Co-doped δ-MnO2 flowers. The fabricated sensor exhibited an excellent detection limit (0.12 µM) and sensitivity of 5.3 µAµM-1 cm-2.Graphical abstract.