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Pollutants are continually being released into the land, water, and air around the world as a result of the high levels of human activity and urbanisation, which cause a rapid an increase in the growth of pollution. To meet the complex specifications needed for the separation of these contaminants regarding selectivity, sensitivity and limit of detection using various nanoparticles, researchers are modifying the electrodes using different nanoparticles. In this study, silver-doped magnesium oxide nanoparticles are prepared via sol–gel method and fabricated Ag-doped MgO-modified electrodes for investigating its electrochemical determination of resorcinol (RS) and RS degradation as measured with photocatalytic activity in the visible region. A number of characterization techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray dispersive spectroscopy (EDS), UV–Vis spectroscopy, XPS and Fourier transform infrared spectroscopy (FTIR) were used to confirm the optical properties, composition and morphology of synthesised Ag doped MgO nanoparticles. While the crystalline size of the synthesised nanoparticles was found to be 28 nm, the strong XRD peaks indicate the high crystallinity of the particles. The detection and quantification limits of the fabricated electrode are found to be 20.2 µM and 61.3 µM, respectively. The correlation value (R2) was ~ 0.99. Pure resorcinol exhibits a maximum absorption peak at 283 nm in its UV–visible spectrum. From the discoloration of resorcinol within 60 min, it can be shown that the synthesised material has a capability to degrade resorcinol effectively in the presence of sodium borohydride. The synthesised Ag-doped MgO nanoparticles degraded the RS with 98% efficiency. [ABSTRACT FROM AUTHOR]

Chromium (Cr), one of the hazardous pollutants, exists predominantly as Cr(VI) and Cr(III) in the environment. Cr(VI) is more toxic than Cr(III) due to its high mobility and solubility. Elevated levels of Cr in agricultural soil due to various anthropogenic activities cause Cr accumulation in plants, resulting in a significant reduction in plant yield and quality due to Cr-induced physiological, biochemical and molecular alterations. It can infiltrate the food chain through crop plants and cause harmful effects in humans via biomagnification. Cr(VI) is linked to cancer in humans. Therefore, mitigation strategies are required to remediate Cr-polluted soils and limit its accumulation in plants for safe food production. Recent research on metal and metal oxide nanoparticles (NPs) has shown that they can effectively reduce Cr accumulation and phytotoxicity. The effects of these NPs are influenced by their type and dose, exposure method, plant species and experimental settings. In this review, we present an up-to-date compilation and comprehensive analysis of the existing literature regarding the process of uptake and distribution of Cr and impact and potential mechanisms of metal and metal oxide nanoparticles led mitigation of Cr-induced stress in plants. We have also discussed recent developments, existing research gaps and future research directions in the field of Cr stress mitigation by NPs in plants. Overall, this review can provide valuable insights in reducing Cr accumulation and toxicity using metal and metal oxide nanoparticles, thereby promoting safe and sustainable cultivation of food and phytostabilization of Cr-polluted soil. [ABSTRACT FROM AUTHOR]

Cocoa pod shells are the byproducts of the cocoa industry. These pod shells were explored for the biogenic synthesis of silver nanoparticles. The synthesized nanoparticles were characterized, and studies were carried out to assess the catalytic and antifungal activities. UV–Vis spectral analysis recorded the surface plasmon resonance at 438 nm. Spherical-shaped particles with a diameter ranging from 48.83 to 55.24 nm were determined by scanning electron microscope. The presence of silver was confirmed through Energy Dispersive X-Ray Analysis. FTIR analysis was carried out to determine the functional groups capped on the surface of the nanoparticles. XRD patterns substantiated the crystalline nature with the sharp peak of 33.16° indicating (101) fcc plane and crystallite size were calculated to be 59.65 nm. Amylase activity was found to be sevenfold higher with a significant amount of 16.05 mg/ml/min in the presence of silver nanoparticles as compared to the control. Methylene blue dye degradation in the presence of silver nanoparticles followed a pseudo-first-order reaction with a degradation constant of 0.1889 min−1 and R2 of 0.9869. In addition, an inhibition activity of 34% against Fusarium oxysporum f. sp. cubense fungi was exhibited by the synthesized silver nanoparticles. The outcome of the investigation has revealed the potential scope of silver nanoparticles as nanocatalysts in starch hydrolysis, dye degradation as well as the antifungal potential. [ABSTRACT FROM AUTHOR]

Nanotechnology is one of the most promising and advanced disciplines of science that deals with synthesis, characterization and applications of different types of Nanomaterials (NMs) viz. nanospheres, nanoparticles, nanotubes, nanorods, nanowires, nanocomposites, nanoalloys, carbon dots and quantum dots. These nanosized materials exhibit different physicochemical characteristics and act as a whole unit during its transport. The unique characteristics and vast applications of NMs in diverse fields viz. electronics, agriculture, biology and medicine have created huge demand of different type of NMs. Conventionally physical and chemical methods were adopted to manufacture NMs which are expensive and end up with hazardous by-products. Therefore, green synthesis exploiting biological resources viz. algae, bacteria, fungi and plants emerged as a better and promising alternative due to its cost effective and ecofriendly approach and referred as nanobiotechnology. Among various living organisms, cyanobacteria have proved one of the most favourable bioresources for NMs biosynthesis due to their survival in diverse econiches including metal and metalloid contaminated sites and capability to withstand high levels of metals. Biosynthesis of metallic NMs is accomplished through bioreduction of respective metal salts by various capping agents viz. alkaloids, pigments, polysaccharides, steroids, enzymes and peptides present in the biological systems. Advancement in the field of Nanobiotechnology has produced large number of diverse NMs from cyanobacteria which have been used as antimicrobial agents against Gram positive and negative human pathogens, anticancer agents, luminescent nanoprobes for imaging of cells, antifungal agents against plant pathogens, nanocatalyst and semiconductor quantum dots in industries and in bioremediation in toxic pollutant dyes. In the present communication, we have reviewed cyanobacteria mediated biosynthesis of NMs and their applications in various fields. [ABSTRACT FROM AUTHOR]

Zinc aluminate (ZnAl2O4) is a well-recognized ceramic demanded in several microwave applications. Further, the addition of dielectric materials in ZnAl2O4 improved its dielectric properties, which is promising for the realization of a microstrip patch antenna. This article reports the investigation of ZnAl2O4TiO2 (ZAT) dielectric ceramic nanoparticles synthesized by the sol–gel process. The X-ray diffraction analysis revealed the crystalline nature of the prepared nanoparticles, with a tetragonal structure of anatase-, and rutile-TiO2 phases coexisting with the cubic phase of ZnAl2O4. The estimated crystallite size of the dielectric ceramic is 13.3 nm. Transmission electron microscopy (TEM) micrographs demonstrated the spherical grains with their mean diameter of 14.75 nm, whereas the selected-area electron diffraction (SAED) pattern endorsed the crystallinity of the sample. Raman measurement revealed the vibrational modes in accordance with the TiO2 and ZnAl2O4 compounds. The dielectric properties of the ZAT sample showed the dielectric permittivity in the range of 22.12–21.63, with its minimum loss from 0.056 to 0.041. Finally, a prototype microstrip antenna was fabricated using the prepared nanoparticles, which demonstrated a return loss of − 30.72 dB at the resonant frequency of 4.85 GHz with its bandwidth of 830 MHz. [ABSTRACT FROM AUTHOR]

Natural products have been widely explored since ancient times to heal human diseases. Due to their biological activities and relative safety, natural products have found applications in functional foods, medicine, pharmaceuticals and nutraceuticals. However, applications are often limited by poor aqueous solubility, instability and poor bioavailability following oral administration. For instance, many natural products exhibit excellent in vitro pharmacological activity, and no or less in vivo activity as a result of poor gastrointestinal absorption. Here we review techniques and materials for bioavailability enhancement such as particle size reduction, surfactant use, pH change, solid dispersion, cyclodextrin complexation, phytosome technology, solid-lipid nanoparticles, liposome and polymeric nanoparticles. Natural substances include quercetin, naringenin, curcumin, hesperetin, andrographolide, ellagic acid, resveratrol, bilobalide sinomenine, genistein, ginkgolide and glycyrrhizin. The clinical use of piperine as bio-enhancer with rifampicin is key achievement in the treatment of tuberculosis. [ABSTRACT FROM AUTHOR]

In this work we demonstrate a novel approach to achieve efficient charge separation in dimensionally and dielectrically confined two-dimensional perovskite materials. Two-dimensional perovskites generally exhibit large exciton binding energies that limit their application in optoelectronic devices that require charge separation such as solar cells, photo-detectors and in photo-catalysis. Here, we show that by incorporating a strongly electron accepting moiety, perylene diimide organic chromophores, on the surface of the two-dimensional perovskite nanoplatelets it is possible to achieve efficient formation of mobile free charge carriers. These free charge carriers are generated with ten times higher yield and lifetimes of tens of microseconds, which is two orders of magnitude longer than without the peryline diimide acceptor. This opens a novel synergistic approach, where the inorganic perovskite layers are combined with functional organic chromophores in the same material to tune the properties for specific applications. Functionalizing two-dimensional (2D) hybrid perovskites with organic chromophores is a novel approach to tune their optoelectronic properties. Here, the authors report efficient charge separation and conduction in 2D hybrid perovskite nanoplatelets by incorporating an electron acceptor chromophore. [ABSTRACT FROM AUTHOR]

Nanoparticles of gamma alumina prepared by sol-gel method, using alcoholic aluminum chloride (AlCl) precursor has been demonstrated as an effective adsorbent for fluoride removal of water. Increasing the molar concentration of AlCl from 0.1 to 0.25 M was found to increase the nanoalumina content in the same ratio with good yield. Different analytical techniques like thermogravimetry and differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy and Brunauer, Emmett and Teller surface area analysis were employed for the characterization of the synthesized nanoparticles whereas batch adsorption studies were performed for the understanding of adsorption kinetics of fluoride in water of neutral pH. Adsorption kinetics has exhibited excellent fluoride removal capability of ~23 mg/g from the nanoparticles derived using up to 0.2 M AlCl precursor. Nanoparticles derived from 0.25 M AlCl have shown comparatively less fluoride removal (~18 mg/g). Langmuir equilibrium model was found more suitable for describing the fluoride adsorption mechanism. Presence of sulphate, carbonate, nitrate, and chloride anions in water influenced the fluoride removal efficiency noticeably. Graphical Abstract: [ABSTRACT FROM AUTHOR]

The synthesis of biogenic nanoparticles from non-chemical resources has increased the drive toward understanding infection biology. Accordingly, we aimed to address the symbiotic antibiofilm effect of biogenic copper and zinc oxide nanoparticles with antimicrobials against multidrug resistant (MDR) pathogens. The minimum inhibitory concentration (MIC) of copper nanoparticles (CuNPs) and zinc oxide nanoparticles (ZnONPs) at the range from 2 to 128 µg/ml was calculated against Gram-positive and Gram-negative pathogenic bacteria using a broth dilution method. Both nanoparticles have prime antibacterial activity compared with standard antibiotics (excluding against P.aeruginosa MTCC 741). A qualitative assessment of biofilm formation and collegial effect was performed using a modified test tube and the microtiter plate-based method by measuring the optical density and time kill of nanoparticles. The results demonstrated efficient antibiofilm activity of CuNPs in its lowest concentration than ZnONPs and antibiotics itself. In addition, significant enhancing antibiofilm effect was also shown by CuNPs in the presence of third generation antibiotics against Gram-negative and Gram-positive bacteria. A scanning electron microscopy (SEM) analysis was used to investigate the effect of the nanoparticles on morphological changes of Staphylococcus aureus. Current data highlights, biogenic CuNPs and ZnONPs could be used as an adjuvant for antibiotics in the treatment of bacterial infections. [ABSTRACT FROM AUTHOR]

Objective: We propose an innovative strategy of nanoparticle-mediated-peptide receptor radionuclide therapy (PRRT) employing PLGA-nanoparticles together with anti-β-hCG antibodies that can protect kidneys from radiation damage while simultaneously enhancing its tumor targeting and cytotoxic ability for somatostatin receptor (SSR) positive tumors.Methods: PEG-coated-(177)Lu-DOTATATE-PLGA-nanoparticles (PEG-LuD-NP) were formulated and characterized. In vitro toxicity of these particles was tested on human glioblastoma cell line U87MG over a radiation dose range of 19-78 Gy, using MTT assay and flow cytometry. To further enhance cytotoxicity and test the feasibility of active tumor targeting, apoptosis-inducing anti-β-hCG monoclonal antibodies were employed in vitro, after confirming expression of β-hCG on U87MG. In vivo tumor targeting ability of these particles, in comparison to uncoated particles and un-encapsulated (177)Lu-DOTATATE, was assessed by intravenous administration in tumor-induced wistar rats. Rats were first imaged in a gamma camera followed by euthanasia for organ extraction and counting in gamma counter.Results: The particles were spherical in shape with mean diameter of 300 nm. Highest cytotoxicity that could be achieved with PEG-LuD-NP, on radio-resistant U87MG cells, was 35.8 % due to complex cellular response triggered by ionizing radiation. Interestingly, synergistic action of antibodies and PEG-LuD-NP doubled the cytotoxicity (80 %). PEG-LuD-NP showed the highest tumor uptake (4.3 ± 0.46 % ID/g) as compared to (177)Lu-DOTATATE (3.5 ± 0.31 %) and uncoated-(177)Lu-DOTATATE-nanoparticles (3.4 ± 0.35 %) in tumor-inoculated wistar rats (p < 0.001). Renal uptake/retention was decreased 3-4 folds with these particles, resulting in the highest tumor-to-kidney ratio (8.58; p < 0.01) while tumor-to-liver and tumor-to-bone ratios were comparable to un-encapsulated-drug.Conclusion: Nanocarrier-mediated-PRRT is an effective way of targeting SSR positive tumors for enhanced cytoxicity and reduced renal radiation dose associated with conventional PRRT. To our knowledge of literature, this is the first study to establish in vitro and in vivo efficacy profile of nanoparticles in PRRT providing a stepping-stone for undergoing and future research endeavors in the direction of abating associated radiation concerns of radionuclide therapy and may offer a paradigm shift in PRRT strategy. [ABSTRACT FROM AUTHOR]

Water solvent-based sol-gel process was employed in the synthesis of nanoparticles of gamma alumina (NPGA) which were used for the removal of fluoride from water of neutral pH. Different techniques like thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction, and field emission scanning electron microscopy were employed for the characterization of the synthesized particles. Batch adsorption studies were performed for the optimization of contact time and adsorbent doses to obtain maximum fluoride removal and understanding of the adsorption kinetics and mechanism. The maximum adsorption capacity of NPGA for fluoride removal was estimated to be nearly 14 mg/g at room temperature (30 °C) which is better than fluoride removal reported by earlier using of commercial-grade NPGA. Adsorption kinetics measurement indicated that Langmuir equilibrium model is found to be more suitable for describing the fluoride adsorption mechanism. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]