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•A novel green synthesis method is employed for the synthesis of copper nanoparticles.•The average size of the synthesized Cu nanoparticles is in the range of 5–25 nm.•The obtained ...nanoparticles have shown good antibacterial activity against gram-positive and gram-negative bacteria.
In the present report, for the first time aqueous extract of Curcuma longa powder is used for the synthesis of Copper nanoparticles (Cu NPs) using a simple and cost effective method. Morphology, size, crystallinity, composition and microstructure of the synthesized Cu Nps are studied. Size of the particles are in the range of 5–20 nm. In addition to the above, antibacterial activity of the obtained Cu NPs is tested for both gram-positive and gram-negative microorganisms. Zone of inhibition of Cu NPs for gram positive bacteria is more compared to gram negative bacteria. The current work on green synthesis of metallic nanoparticles can be considered as an alternative method to avoid the usage of hazardous compounds and bitter reaction conditions in the production of metal nanoparticles. The obtained Cu NPs with their distinctive structural properties and effective biological effects can be used in applications viz. antimicrobial, antifungal, anticancer activity.
In this paper, the problem of autonomous optimal absolute orbit keeping for a satellite mission in Low Earth Orbit using electric propulsion is considered. The main peculiarity of the approach is to ...support small satellite missions in which the platform is equipped with a single thruster nozzle that provides acceleration on a single direction at a time. This constraint implies that an attitude maneuver is necessary before or during each thrusting arc to direct the nozzle into the desired direction. In this context, an attitude guidance algorithm specific for the orbit maneuver has been developed. A Model Predictive Control scheme is proposed, where the attitude kinematics are coupled with the orbital dynamics in order to obtain the optimal guidance profiles in terms of satellite state, reference attitude, and thrust magnitude. The proposed control scheme is developed exploiting formation flying techniques where the reference orbit is that of a virtual spacecraft that the main satellite is required to rendezvous with. In addition to the controller design, the closed-loop configuration is presented supported by numerical simulations. The efficacy of the proposed autonomous orbit-keeping approach is shown in several application scenarios.
At present tuneable properties and morphology of polymer composites have become fundamental forefront research interest in sensing applications. Using existing approaches with a new idea, this paper ...reports the synthesis of Polyaniline nanosheets (PANINS) with surface modification by nickel oxide nanoparticles (NiO) through in situ polymerization. The morphology and presence of functional groups of as obtained NiO-NPs @PANINS witnessed the formation of the thin surface of PANINS decorated by NiO-NPs using FESEM, TEM, and FTIR. The structural analysis of as prepared NiO-NPs and NiO-NPs@PANINS confirmed the crystallinity by insignificant stacking fault, dislocation density, and microstrain. Furthermore, the synthesized NiO and NiO@PANINS were used as a modified screen-printed electrode (SPE) for the fabrication of electrochemical non-enzymatic glucose sensor. The invented sensor used for amperometric non-enzymatic glucose sensor exhibited a high sensitivity of 5625 μA mM−1 cm−2, and low detection limit 0.06 μM. Besides that, the interference study shows excellent selectivity and also retains good stability. We believe that this NIO@PANINS nanocomposite could be utilized as low cost, an eco-friendly efficient electrode for the electrochemical biological sensor.
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•The NiO-NPs@PANINS was synthesized using SDS through in-situ polymerization method.•The NiO-NPs@PANINS/SPE used for non-enzymatic glucose sensing in 0.1 M NaOH. .•The NiO-NPs@PANINS/SPE showed a high sensitivity of 5625 μAmM−1cm−2 & LOD 0.06 μM.•NiO-NPs@PANINS/SPE was better for its selectivity, ease of synthesis and lowcost.
We fabricated a fourth generation glucose biosensor using CeO2@CuO core shell nano structure (CeCCS NSs). A simple leave extract of Ocimum tenuiflorum was used to prepare different wt% of 0.2, 04, ...0.6, and 0.8 CuO (shell), above 1 wt% of CeO2 (core). The successful formation was confirmed by various characterization techniques like XRD, Uv–Vis, FTIR, SEM and HR-TEM. In the biosensor, 0.4 wt% of CeCCS NSs has shown efficient properties due to its high surface area. The good conductivity and high catalytic activity towards glucose sensing properties were estimated by screen-printed electrode (SPE). The ampherometric studies of CeCCS/SPE modified electrode have been optimized at potential + 0.4 V, showed a sensitivity of 3319.83 μAm M−1 cm−2 within detection limit of 0.019 μM. More significantly, modified electrodes performed excellently against anti-interference and anti-poisoned activity in glucose sample and exhibited promising results for the sustainable improvement for non-enzymatic sensing applications.
•Ocimum tenuiflorum leaf extract were used to prepare Ag@CuO core shell nanostructure.•Structural, optical and morphological properties are studied.•The ACCS/SPE showed a sensitivity of 3319.83 μAmM−1 cm−2.•Bio-mediated route synthesized NSs shows sustainable sensing properties.
The n-type Ce doped ZnO (Ce–ZnO) and p-type polyaniline (PANI) heterojunction were successfully synthesized via simple chemical solution method for sensing liquefied petroleum gas (LPG) at standard ...environment. The morphology and structures of as-prepared Ce–ZnO & PANI nanoparticles were analyzed by numerous kinds of techniques. Ce–ZnO & PANI nanoparticles were mixed with n-methylpyrrolidone (NMP) which is coated over the gold coated PET electrode by doctor blade method and dried overnight at 60 °C to form p-n junction. The as-formed p-n junction is to be driven with the help of 1.5 V potential at ambient temperature. X-ray photoelectron spectroscopy results of Ce–ZnO nanoparticles confirmed the existence of Ce4+ and the improved amount of both chemisorbed oxygen and oxygen vacancy after the formation of Ce–ZnO heterojunction. The maximum response of 80% was realized for hollow Ce–ZnO/PANI sensor at 100 ppm. The proposed material is a novel candidate to detect the LPG even at low (30) ppm and this study reveals the possibility of developing a potentially inexpensive hollow Ce–ZnO/PANI sensor for sensing LPG efficiently.
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•Synthesis of Ce–ZnO nanoparticles and PANI by simple hydrothermal method.•The fabricated Ce–ZnO/polyaniline was high sensitive at low ppm of LPG.•The maximum response was observed to be 80% at 100 ppm for porous Ce–ZnO/polyaniline.•Applicable for real time LPG sensing at low ppm.
The present work reports the synthesis of magnesium oxide nanoparticles (MgO NP’s) using
A. barbadensis Mill
(aloe vera) as the stabilizer by green synthesis approach as well as solution-combustion ...method. The morphological, structural and optical properties of synthesized MgO NP’s were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The characterization results show the fibrous shaped porous structure of synthesized MgO NP’s with size range of 2–25 nm. The as-synthesized MgO NP’s were subjected to sensing of liquefied petroleum gas (LPG) having different concentration ranges (400–1000 ppm) and different operating temperatures along with dynamic characteristics. The sensor exhibits high selectivity and sensitivity towards LPG.
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•Sm2O3 rice like nanorods was prepared by ESM-assisted hydrothermal method.•Sensitivity, stability and selectivity parameters analyzed for Sm2O3/rGO sensor towards LPG at RT.•The ...sensing mechanism explained based on Chemiresistive model.
Flexible electrochemical sensors have gained huge attention over their significant properties and the probability of applying to any wearable electronic devices. LPG traces in definite concentrations leads to a fire accident, adverse health effects, and even causes death. The current study focuses on a flexible, room temperature LPG sensor based on Sm2O3/rGO hybrid nanocomposite with different loading factors (1, 3, and 5 wt%) coated on flexible polyethylene terephthalate (PET) substrate working electrodes. Eggshell membrane (ESM) template constituents are acts as a reducing agent during the hydrothermal synthesis of Sm2O3 nanorods. Flexible Sm2O3/rGO hybrid Chemiresistive gas sensor was tested for various gas sensing parameters. The decoration of Sm2O3 nanorods on 3 wt% rGO sheets exhibited good selectivity to liquefied petroleum gas (LPG) at room temperature gives a response of 116% at 700 ppm of LPG with a short response, recovery time and gained 99% response after bending with 94.5% stability of the sensor.
An enzyme-free glucose sensor developed based on silver nanoparticles (Ag NPs) via bio-mediated route using Ocimum tenuiflorum leaves extract. The Ag NPs were characterized by X-ray diffraction ...(XRD), ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Particle size analyzer (PSA), Scanning electron microscopy (SEM), Energy-dispersive X-ray (EDAX) spectroscopy, and Transmission electron microscopy (TEM), to study structural, optical and morphological properties. The electrocatalytic activity of Ag NPs towards the oxidation of glucose in the 0.1 M NaOH electrolyte solution was analyzed. The Ag NPs was coated on Glassy carbon electrode (GCE) and reports indicating the outstanding capability such as high sensitivity (895.8 μAmM−1cm−2), linear range (1–8.9 mM), response time (<4s), low detection limit (0.0048 μM, S/N = 3), long-term stability, reproducibility, repeatability, and selectivity of the sensor. Therefore, the bio-synthesized Ag NPs can markedly helpful to fabricate non-enzymatic, sustainable, simple, low cost, and eco-friendly glucose monitoring devices.
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•Ocimum tenuiflorum leaf extract and silver nitrate were used to prepare Ag NPs.•Structural, optical and morphological properties of Ag NPs were studied.•The GCE modified with Ag NPs showed a sensitivity of 895.8 μAmM−1cm−2.•Bio-mediated synthesized NPs showed sustainable glucose sensing properties.
Since the last decade, electrospinning is garnering more attention in the scientific research community, industries, applications like sensing (glucose, H2O2, dopamine, ascorbic acid, uric acid, ...neurotransmitter, etc.), biomedical applications (wound dressing, wound healing, skin, nerve, bone tissue engineering, and drug delivery systems), water treatment, energy harvesting, and storage applications. This review paper provides a brief overview of the electrospinning method, history of the electrospinning, factors affecting the electrospun nanofibers, and their morphology with different materials and composites (metals, metal oxides, 2D material, polymers and copolymers, carbon‐based materials, etc.) used in the electrospinning technique with optical spinning parameters. Moreover, this paper deliberates the application of electrospun nanofibers and fibrous mats for sensing (electrochemical, optical, fluorescence, colorimetric, mechanical, photoelectric, mass sensitive change, resistive, ultrasensitive, etc.) in most illustrative representations. In the end, the challenges, opportunities of the electrospun nanofibers, and new direction for future progress are also discussed.
Electrospinning is one of the emergent routes in research community. Based on the importance of the electrospinning, this study enlightens the history, synthesis of electrospun nanofibers, and fibrous mats with parameters variation and their utilization in sensor field with most recent and advanced examples. Considering the results, the prospects and their new future developments are discussed.
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•Green synthesis of herbal mediated iron oxide nanoparticles for biomedical application is proposed.•The phytochemicals of the plant act as efficient capping and stabilizing agent ...hence can be used in therapy.•The acute toxicity studies performed showed the non-toxic nature of the iron oxide nanoparticles.
Biosynthesis of nanoparticles using plant extracts is gaining importance in biomedical applications because of their unique properties. The present study was aimed to investigate the novel use of ethanolic extract of Centella asiatica (CA) whole plant to synthesize iron oxide nanoparticles (CAIONPs) by reducing ferrous and ferric chlorides. FTIR of CAIONPs showed a coating of phytochemicals present in the ethanolic extract of CA indicating possible role as capping and efficient stabilization of the CAIONPs. The XRD confirmed the crystalline structure of CAIONPs with an average crystalline size of 15.2 nm, and found to be spherical in shape from SEM and TEM images. From VSM, superparamagnetic nature with a saturation magnetization of 13.8 emu/g was observed. Swiss albino mice treated with CAIONPs at 2000 mg/kg b.w showed no mortality and signs of toxicity during the treatment period.
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