The practice of bone implants is the standard procedure for the treatment of skeletal fissures, or to substitute and re-establish lost bone. A perfect scaffold ought to be made of biomaterials that duplicate the structure and properties of natural bone. However, the production of living tissue constructs that are architecturally, functionally and mechanically comparable to natural bone is the major challenge in the treatment and regeneration of bone tissue in orthopaedics and in dentistry. In this work, we have employed a polymeric replication method to fabricate hydroxyapatite (HAP) scaffolds using gum tragacanth (GT) as a natural binder. GT is a natural gum collected from the dried sap of several species of Middle Eastern legumes of the genus Astragalus, possessing antibacterial and wound healing properties. The synthesized porous HAP scaffolds were analyzed structurally and characterized for their phase purity and mechanical properties. The biocompatibility of the porous HAP scaffold was confirmed by seeding the scaffold with Vero cells, and its bioactivity assessed by immersing the scaffold in simulated body fluid (SBF). Our characterization data showed that the biocompatible porous HAP scaffolds were composed of highly interconnecting pores with compressive strength ranging from 0.036 MPa to 2.954 MPa, comparable to that of spongy bone. These can be prepared in a controlled manner by using an appropriate binder concentration and sintering temperature. These HAP scaffolds have properties consistent with normal bone and should be further developed for potential application in bone implants.
The rapid consumption of metals and unorganized disposal have led to unprecedented increases in heavy metal ion concentrations in the ecosystem, which disrupts environmental homeostasis and results in agricultural biodiversity loss. Mitigation and remediation plans for heavy metal pollution are largely dependent on the discovery of cost-effective, biocompatible, specific, and robust detectors because conventional methods involve sophisticated electronics and sample preparation procedures. Carbon dots (CDs) have gained significant importance in sensing applications related to environmental sustainability. Fluorescence sensor applications have been enhanced by their distinctive spectral properties and the potential for developing efficient photonic devices. With the recent development of biomass-functionalized carbon dots, a wide spectrum of multivalent and bivalent transition metal ions responsible for water quality degradation can be detected with high efficiency and minimal toxicity. This review explores the various methods of manufacturing carbon dots and the biochemical mechanisms involved in metal detection using green carbon dots for sensing applications involving Cu (II), Fe (III), Hg (II), and Cr (VI) ions in aqueous systems. A detailed discussion of practical challenges and future recommendations is presented to identify feasible design routes.
Bismuth sulfide nanoparticles (BiS NPs) were synthesized via the hydrothermal method, and reduced graphene oxide(rGO) and silver nanoparticles (Ag), which acted as substrates, have prepared using the chemical reduction method. The synthesized nanoparticles have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy, and photoluminescence spectroscopy. Commercially available paracetamol-500 mg (PAM) and aspirin-300 mg (ASP) were selected for photodegradation under visible light using the as-prepared composites in an aqueous solution. Photoluminescence spectroscopy was used to detect PAM and ASP using the photo-excited electron transfer (PET) process, and the limit of detection (LOD) has obtained for PAM(8.70 ppm) and ASP(4.43 ppm) with a sensitivity of 0.9954 and 0.8002, respectively. Fourier transform infrared spectroscopy (FTIR) was used to analyze the before and after degradation products and to confirm the disintegrated products such as -COOH and -CH- both before and after disintegration.. The experimental data were found to fit well with the Freundlich isotherm, suggesting that the as-prepared nanocomposites exhibited a heterogeneous nature for PAM (5119 mg/L), and the pseudo-first-order kinetic model suggests ASP (1030 mg/L) with R2 values of 0.9119 and 0.7075. The risk assessment analysis of PAM was 9.823 μg/L(RQ > 1) and that of ASP was 0.2106 μg/L(RQ
This investigation aims at the reclamation of Cr(VI) from synthetic electroplating industrial effluent by electroextraction process namely electrochemical ion exchange (EIX). An electrochemical ion exchange reactor of desired dimensions was fabricated with the help of ion-permeable membranes, stainless steel cathode and PbO₂ coated Ti expanded mesh anode. The performance of the reactor was studied in batch recirculation mode, continuous flow mode at different experimental conditions. The influence of various experimental factors, for instance, initial metal ion concentration (20, 300, 1000 mg/L of Cr(VI)), applied voltages (2.5 V, 5 V, 7.5 V, 10 V) and flow rates of the process stream (2, 4, 6, 8, 10, 12 and 14 ml/min) on removal/reclamation efficiency was deliberated. For comparison purposes, an electrodialysis process was conducted at the same optimal conditions. It was found that the EIX process with three compartments has more removal efficiency at optimum experimental conditions than the electrodialysis process. The continuous flow process of the reactor with 300 mg/L of Cr(VI) as inlet concentration has studied to predict the breakeven point of the reactor. It was noted that Cr(VI) ion concentration in the treated wastewater is almost zero up to the discharge of 20 liters of treated rinse water.
Titanium dioxide (TiO2) nanoparticles (NPs) have been doped with varying amounts (0.005, 0.010 and 0.015 M) of silver nanoparticles (Ag NPs) using hydrothermal method. Further, in this work, a green approach was followed for the formation of Ag@TiO2 NPs using Aloe vera gel as a capping and reducing agent. The structural property confirmed the presence of anatase phase TiO2. Increased peak intensity was observed while increasing the Ag concentration. Further, the morphological and optical properties have been studied, which confirmed the effective photocatalytic behavior of the prepared Ag@TiO2 NPs. The photocatalytic performance of Ag@TiO2 has been considered for the degradation of picric acid in the visible light region. The concentration at 0.010 M of the prepared Ag@TiO2 has achieved higher photocatalytic performance within 50 min, which could be attributed to its morphological behavior. Similarly, anticancer activity against lung cancer cell lines (A549) was also determined. The Ag@TiO2 NPs generated a large quantity of reactive oxygen species (ROS), resulting in complete cancer cell growth suppression after their systemic in vitro administration. Ag@TiO2 NPs was adsorbed visible light that leads to an enhanced anticancer sensitivity by killing and inhibiting cancer cell reproduction through cell viability assay test. It was clear that 0.015 M of Ag@TiO2 NPs were highly effective against human lung cancer cell lines and showed increased production of ROS in cancer cell lines due to the medicinal behavior of the Aloe vera gel.
Graphene is a two-dimensional (2D) material with a single atomic crystal structure of carbon that has the potential to create next-generation devices for photonic, optoelectronic, thermoelectric, sensing, wearable electronics, etc., owing to its excellent electron mobility, large surface-to-volume ratio, adjustable optics, and high mechanical strength. In contrast, owing to their light-induced conformations, fast response, photochemical stability, and surface-relief structures, azobenzene (AZO) polymers have been used as temperature sensors and photo-switchable molecules and are recognized as excellent candidates for a new generation of light-controllable molecular electronics. They can withstand trans-cis isomerization by conducting light irradiation or heating but have poor photon lifetime and energy density and are prone to agglomeration even at mild doping levels, reducing their optical sensitivity. Graphene derivatives, including graphene oxide (GO) and reduced graphene oxide (RGO), are an excellent platform that, combined with AZO-based polymers, could generate a new type of hybrid structure with interesting properties of ordered molecules. AZO derivatives may modify the energy density, optical responsiveness, and photon storage capacity, potentially preventing aggregation and strengthening the AZO complexes. They are potential candidates for sensors, photocatalysts, photodetectors, photocurrent switching, and other optical applications. This review aimed to provide an overview of the recent progress in graphene-related 2D materials (Gr2MS) and AZO polymer AZO-GO/RGO hybrid structures and their synthesis and applications. The review concludes with remarks based on the findings of this study.
Highly-effective photocatalyst of NiO/g-C3N4 with was successfully synthesized by using phyto-mediated-synthesized nickel nanoparticles. The preparation was initiated by synthesizing nickel nanoparticles by using Tinosphora cordifolia stem extract under ultrasound-assisted method followed by the dispersing onto g-C3N4 structure. The study focused on physicochemical characterization and photocatalytic activity as function of the percentage of Ni in the nanocomposite. The photocatalytic activity examinations were carried out to rhodamine B and tetracycline photocatalytic oxidation. The results demonstrated that graphitic carbon nitride is effectively improved the photocatalytic activity of NiO for both photocatalytic oxidation reactions. From the varied Ni content of 5; 10; and 20 %wt., it was also found that the highest photoactivity was achieved by the composite having 10 %wt. of nickel content. The high effectivity was showed by degradation efficiency of 95% toward Rhodamine B and 98% toward tetracycline. The examination on effect of scavengers suggests that Z-scheme involved in the photocatalytic mechanism which facilitated the efficient separation of the photogenerated electron-hole pairs under visible light illumination. In summary, the present findings provide a green approach for fabricating the effective photocatalysts for organic contaminant degradation.
The present study deals with the effects of curcumin-loaded ZnO nanoparticles (NPs) embedded in graphitic-carbon nitride (g-C3N4) sheets for breast cancer cells. The synthesis of these sheets was carried out by a simple co-precipitation method. The physicochemical and thermal properties of the composite sheets were studied using various characterization techniques. The powder X-ray diffraction and high-resolution transmission electron microscopy analyses confirmed the hexagonal wurtzite phase of the ZnO nanoparticles, which were randomly distributed on the g-C3N4 nanosheets, generating a finely bonded interface between the two components. The X-ray photoelectron spectroscopy analysis confirmed the successful formation of the g-C3N4@ZnO composite, while the thermal studies revealed the thermal stability of the composite. In addition, the drug release and kinetics studies proved that the release of curcumin was more significant under acidic conditions (pH 5) compared with neutral pH (7.4). Further, the biological assays verified the antibacterial activity (against two different cultures of E. coli and S. aureus) and anticancer activity (against MDA-MB-231 cancer cells) of the g-C3N4@ZnO/C nanocomposite. Finally, the lactate dehydrogenase activity assay presented the cytotoxic assessment of the nanocomposite based on its cytoplasmic activity and the extent of enzymes released from the damaged cells.
Nickel-substituted copper ferrite nanoparticles (NP) (Cu1-xNixFe2O4) were prepared using a cost-effective hydrothermal method. X-ray diffraction (XRD) pattern revealed a single-phase cubic spinel structure. The increase in lattice parameters and decrease in crystallite size are associated with the replacement of Cu ions by Ni ions in the host lattice of copper ferrite. The optimized Cu0.95Ni0.05Fe2O4 composition was subsequently annealed at 750 °C and 850 °C for further studies. Fourier transform infrared (FT-IR) analysis shows the existence of two promising fundamental adsorption peaks at 465 and 582 cm-1, related to the metal ion stretching vibrations at the tetrahedral (A) and octahedral (B) sites, respectively. The local disorder at both the A and B sublattices upon the incorporation of Ni was observed from the Raman analysis. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) images shows the formation of agglomerates composed of nano-sized spherical particles. A high Barrett-Joyner-Halenda (BJH) surface area was achieved 17.25 m2/g with a particle stability of -11.1 mV obtained by the zeta potential. Both the dielectric loss and dielectric constant are decreased, whereas the AC conductivity gets increased with increasing frequency. The magnetization-field hysteresis curves exhibited ferromagnetic behavior with a pseudo-single domain, and the cyclic voltammetry study revealed a pseudocapacitive trend. This study highlights the importance of Ni substitution to control the physicochemical properties of spinel-phase CuFe2O4 for diverse applications, such as energy storage and lithium-ion batteries.
In recent years, intensive research efforts have focused on translating biomass waste into value-added carbon materials broadcasted for their significant role in energy and environmental applications. For the first time, high-performance carbonaceous materials for energy storage applications were developed from the multi-void structure of the boat-fruited shells of Sterculia Foetida (SF). In that view, synthesized mesoporous graphitic activated carbon (g-AC) via the combination of carbonization at various elevating temperatures of 700, 800, and 900 °C, respectively, and alkali activation by KOH, with a high specific surface area of 1040.5 m2 g-1 and a mesopore volume of 0.295 cm3 g-1. In a three-electrode configuration, the improved electrode (SF-K900) exhibited excellent electrochemical behavior, which was observed in an aqueous electrolyte (1 M H2SO4) with a high specific capacitance of 308.6 F/g at a current density of 1 A/g, owing to the interconnected mesopore structures and high surface area of SF-K900. The symmetric supercapacitor (SSC) delivered the specific capacitance of 138 F/g at 1 A/g with a high energy density (ED) of 13.4 Wh/kg at the power density (PD) of 24.12 kW/kg with remarkable cycle stability and supercapacitive retention of 93% over 5000 cycles. Based on the findings, it is possible to develop low-cost active electrode materials for high-rate performance SSC using mesoporous g-AC derived from SF boat-fruited shells.
Exploring the new catalytic systems for the reduction of organic and inorganic pollutants from an indispensable process in chemical, petrochemical, pharmaceutical and food industries, etc. Hence, in the present work, authors motivated to synthesize bare reduced graphene oxide (rGO), polyaniline (PANI), three different ratios of rGO-PANI(80:20,50:50, 10:90) composites and rGO-PANI(80:20,50:50, 10:90) supported mono (Pd) & bimetallic [Pd: Au(1:1,1:2, 2:1)] nanocomposite by a facile chemical reduction method. Also, it investigated their catalytic performances for the reduction of organic/inorganic pollutants and antimicrobial activities. All the freshly prepared bare rGO, PANI, three different ratios of rGO-PANI(80:20, 50:50,10:90) composites and rGO-PANI(80:20, 50:50,10:90)/Pd & Pd: Au(1:1, 1:2,2:1) nanocomposite hybrid catalysts were characterized using UV-Vis, FT-IR, SEM, FE-SEM, EDAX, HR-TEM, XRD, XPS and Raman spectroscopy analysis. Among them, an optimized best composition of rGO-PANI(80:20)/Pd: Au(1:1) bimetallic nanocomposite hybrid catalyst exhibits better catalytic reduction and antimicrobial activities than other composites, as a result of strong electrostatic interactions between rGO, PANI and bimetal (Pd: Au) NPs through a synergistic effect. Hence, an optimized rGO-PANI(80:20)/Pd:Au(1:1) bimetallic nanocomposite catalyst would be considered as a suitable catalyst for the reduction of different nitroarenes, organic dyes, heavy metal ions and also significantly inhibit the growth of S. aureus, S. Typhi as well as Candida albicans and Candida kruesi in wastewater.
Herein, we report the facile synthesis, characterization and visible-light-driven photocatalytic degradation of perforated curly Zn0.1Ni0.9O nanosheets synthesized by hydrothermal process. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies confirmed the cubic phase crystalline structure and growth of high density perforated curly Zn0.1Ni0.9O nanosheets, respectively. As a photocatalyst, using methylene blue (MB) as model pollutant, the synthesized nanosheets demonstrated a high degradation efficiency of ~76% in 60 min under visible light irradiation. The observed results suggest that the synthesized Zn0.1Ni0.9O nanosheets are attractive photocatalysts for the degradation of toxic organic waste in the water under visible light.
Photocatalysts provide excellent potential for the full removal of organic chemical pollutants as an environmentally friendly technology. It has been noted that under UV-visible light irradiation, nanostructured semiconductor metal oxides photocatalysts can degrade different organic pollutants. The Sn6SiO8/rGO nanocomposite was synthesized by a hydrothermal method. The Sn6SiO8 nanoparticles hexagonal phase was confirmed by XRD and functional groups were analyzed by FT-IR spectroscopy. The bandgap of Sn6SiO8 nanoparticles (NPs) and Sn6SiO8/GO composites were found to be 2.7 eV and 2.5 eV, respectively. SEM images of samples showed that the flakes like morphology. This Sn6SiO8/rGO nanocomposite was testing for photocatalytic dye degradation of MG under visible light illumination and excellent response for the catalysts. The enhancement of photocatalytic performance was mainly attributed to the increased light absorption, charge separation efficiency and specific surface area, proved by UV-vis DRS. Further, the radical trapping experiments revealed that holes (h+) and superoxide radicals (·O-₂) were the main active species for the degradation of MG, and a possible photocatalytic mechanism was discussed.
Biosynthesis of nanoparticles has now become a novel trend in addressing some of the environmental issues by adopting eco-friendly approaches in manoeuvring nanoparticles for various applications. Plants and micro-organisms have been the potential sources of the biological mode of synthesizing nanoparticles as part of their bioremediation process. This principle has been harnessed for synthesizing nanoparticles either extra or intracellularly. In this line of phyto-mediated synthesis, eucalyptus buds have been used for synthesizing gold nanoparticles (Au NPs) under optimized laboratory conditions. The UV-visible spectrum of the Au NPs showed typical surface plasmon resonance at 550 nm (λmax) with a crystalline phase measuring <100 nm in size and monodispersed as revealed from XRD, FESEM, and AFM analyses. The biological role of phytochemical concoction in reducing and stabilizing the Au NPs was clearly identified from FT-IR studies. The antimicrobial effect of the Au NPs against clinically important pathogens viz. Staphylococcus sp., Pseudomonas sp., Bacillus sp. and E. coli determined using the disk diffusion method showed no significant antibacterial effect at all concentrations. Cytotoxicity studies were carried using Vero and HEp-2 cell lines and the 50% inhibition concentration (IC50) was determined to be 1.25 mg and 0.625 mg/mL respectively. Au NPs with potential antimicrobial and anti-proliferative effects could found profound implications in the field of nanomedicine once the toxicity in vivo has been investigated.
Graphene oxide/Cuprous oxide (GO/Cu₂O) composite is a visible light photocatalyst for the degradation of dyes. A simple and efficient approach for preparing GO/Cu₂O composite adopted in this study involves reducing cuprous oxide precursors in the presence of graphene oxide using an aqueous solution of pulp derived from banana fruit. The GO/Cu₂O composite was characterized by Fourier transform infrared spectroscopy (FT-IR), Diffused reflectance Ultraviolet visible spectroscopy (DRS UV-Vis), Raman spectroscopy and Field Emission Scanning electron microscopy (FE-SEM). Cu₂O particles were distributed randomly on the graphene oxide sheets due to the template effect of GO. The results showed higher photocatalytic activity for the composite (band gap 2.13 eV), for the degradation of the organic dyes (Methylene blue and Rhodamine-B). The enhanced photocatalytic activity is due to effective charge transfer from GO to Cu₂O, and high specific surface area which improves the effective separation of the generated electron-hole pairs. Our present study is inspired by a facile, low cost, green production of (GO/Cu₂O) composite whose photocatalytic activity can be extended to degradation of all other water-born textile dyes.
In the present study, electrochemical sensing for urea was proposed utilizing graphene-based quaternary nanocomposites YInWO4-G-SiO2 (YIWGS). These YIWGS nanocomposites were utilized due to their exceptionally delicate determination of urea with the lowest detection limit (0.01 mM). These YIWGS composites were developed through a simple self-assembly method. From physical characterization, we found that the YIWGS composites are crystalline in nature (powdered X-ray diffraction), and Fourier transform infrared (FTIR) spectroscopy analysis provided the surface functionality and bonding. Scanning electron microscopy (SEM) studies indicated the morphology characteristics of the as-synthesized composites and the high-resolution transmission electron microscopy (HRTEM) image supported the formation of cubic or hexagonal morphology of the YIW nanocomposites. The YIWGS sensor showed a great electroanalytical sensing performance of 0.07 mM urea with a sensitivity of 0.06 mA cm-2, an expansive linear range of 0.7-1.5 mM with a linear response (R2 1/4 0.99), and an eminent reaction time of around 2 s. It also displayed a good linear response toward urea with negligible interferences from normal coinciding species in urine samples.
Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus are the most significant aquatic pathogens of the genera Vibrio, account for most Vibrio-associated outbreaks worldwide. Rapid identification of these pathogens is of great importance for disease surveillance, outbreak investigations and food safety maintenance. Traditional culture dependent methods are time-consuming and labor-intensive whereas culture-independent polymerase chain reaction (PCR) based assays are reliable, consistent, rapid and reproducible. This review covers the recent development and applications of PCR based techniques, which have accelerated advances in the analysis of nucleic acids to identify three major pathogenic vibrios. Emphasis has been given to analytical approaches as well as advantages and limits of the available methods. Overall, this review article possesses the substantial merit to be used as a reference guide for the researchers to develop improved PCR based techniques for the differential detection and quantification of Vibrio species.
The present study reported biofabrication of flower-like SnO2 nanoparticles using Pometia pinnata leaf extract. The study focused on the physicochemical characteristics of the prepared SnO2 nanoparticles and its activity as photocatalyst and antibacterial agent. The characterization was performed by XRD, SEM, TEM, UV-DRS and XPS analyses. Photocatalytic activity of the nanoparticles was examined on bromophenol blue photooxidation; meanwhile, the antibacterial activity was evaluated against Klebsiella pneumoniae, Escherichia coli Staphylococcus aureus and Streptococcus pyogenes. XRD and XPS analyses confirmed the single tetragonal SnO2 phase. The result from SEM analysis indicates the flower like morphology of SnO2 nanoparticles, and by TEM analysis, the nanoparticles were seen to be in uniform spherical shapes with a diameter ranging from 8 to 20 nm. SnO2 nanoparticles showed significant photocatalytic activity in photooxidation of bromophenol blue as the degradation efficiency reached 99.93%, and the photocatalyst exhibited the reusability as the degradation efficiency values were insignificantly changed until the fifth cycle. Antibacterial assay indicated that the synthesized SnO2 nanoparticles exhibit an inhibition of tested bacteria and showed a potential to be applied for further environmental and medical applications.
Meat and meat products are widely consumed worldwide as a source of high-quality proteins, essential amino acids, vitamins, and necessary minerals. The acceptability of Halal and Kosher meat products relies not only on the species origin but also on the manner of slaughtering of animals. Both Islam and Judaism have their own dietary laws in their holy books regarding acceptance and forbiddance of dietary items particularly meat and meat products. They also include many strictures to follow for ritual cleanliness of foods. Since the authenticity of Halal and Kosher food created increased concerns among consumers, the integrity of Halal and Kosher meat and meat products must be assured so that consumers can be accomplished with the originality of products. There is an increasing demand for reliable and sensitive techniques for the authentication of various Halal and Kosher meat products. This up-to-date review intends to provide an updated and extensive overview critically on the present situation, progress, and challenges of analytical techniques to authenticate animal species in meat items. It also addresses slaughtering procedure with brief discussion on Halal and Kosher laws with a view to creating consumer awareness against fraudulent practices. The available methods are schematically presented, and their salient features are comparatively elucidated in tables. Potential future technologies are predicted, and probable challenges are summarized. Overall, the present review article possesses substantial merits to be served as a reference guide in the field of academia and industry for the preparation/processing and identification of Halal and Kosher meat and meat products as well as may act as a platform to help improve existing authentication methods.
Aerospace equipages encounter potential radiation footprints through which soft errors occur in the memories onboard. Hence, robustness against radiation with reliability in memory cells is a crucial factor in aerospace electronic systems. This work proposes a novel Carbon nanotube field-effect transistor (CNTFET) in designing a robust memory cell to overcome these soft errors. Further, a petite driver circuit to test the SRAM cells which serve the purpose of precharge and sense amplifier, and has a reduction in threefold of transistor count is recommended. Additionally, analysis of robustness against radiation in varying memory cells is carried out using standard GPDK 90 nm, GPDK 45 nm, and 14 nm CNTFET. The reliability of memory cells depends on the critical charge of a device, and it is tested by striking an equivalent current charge of the cosmic ray's linear energy transfer (LET) level. Also, the robustness of the memory cell is tested against the variation in process, voltage and temperature. Though CNTFET surges with high power consumption, it exhibits better noise margin and depleted access time. GPDK 45 nm has an average of 40% increase in SNM and 93% reduction of power compared to the 14 nm CNTFET with 96% of surge in write access time. Thus, the conventional MOSFET's 45 nm node outperforms all the configurations in terms of static noise margin, power, and read delay which swaps with increased write access time.