Synthesis, Characterization, and Evaluation of Silver Nanoparticle-Loaded Carboxymethyl Chitosan with Sulfobetaine Methacrylate Hydrogel Nanocomposites for Biomedical Applications.

In this study, nanocomposites of AgNPs encapsulated in carboxymethyl chitosan (CMCS) with sulfobetaine methacrylate (SB) hydrogel (AgNPs/CMCS-SB) were synthesized. The UV-Vis spectra indicated the presence of AgNPs, with a broad peak at around 424 nm, while the AgNPs-loaded CMCS-SB nanocomposite exhibited absorption peaks at 445 nm. The size and dispersion of AgNPs varied with the concentration of the AgNO3 solution, affecting swelling rates: 148.37 ± 15.63%, 172.26 ± 18.14%, and 159.17 ± 16.59% for 1.0 mM, 3.0 mM, and 5.0 mM AgNPs/CMCS-SB, respectively. Additionally, water absorption capacity increased with AgNPs content, peaking at 11.04 ± 0.54% for the 3.0 mM AgNPs/CMCS-SB nanocomposite. Silver release from the nanocomposite was influenced by AgNO3 concentration, showing rapid initial release followed by a slower rate over time for the 3.0 mM AgNPs/CMCS-SB. XRD patterns affirmed the presence of AgNPs, showcasing characteristic peaks indicative of a face-centered cubic (fcc) structure. The FTIR spectra highlighted interactions between AgNPs and CMCS-SB, with noticeable shifts in characteristic bands. In addition, SEM and TEM images validated spherical AgNPs within the CMCS-SB hydrogel network, averaging approximately 70 and 30 nm in diameter, respectively. The nanocomposite exhibited significant antibacterial activity against S. aureus and E. coli, with inhibition rates of 98.9 ± 0.21% and 99.2 ± 0.14%, respectively, for the 3.0 mM AgNPs/CMCS-SB nanocomposite. Moreover, cytotoxicity assays showcased the efficacy of AgNPs/CMCS-SB against human colorectal cancer cells (HCT-116 cells), with the strongest cytotoxicity (61.7 ± 4.3%) at 100 µg/mL. These results suggest the synthesized AgNPs/CMCS-SB nanocomposites possess promising attributes for various biomedical applications, including antimicrobial and anticancer activities, positioning them as compelling candidates for further advancement in biomedicine.

Formulation of Ensulizole with Beta-Cyclodextrins for Improved Sunscreen Activity and Biocompatibility.

In today's context, prolonged exposure to sunlight is widely recognized as a threat to human health, leading to a range of adverse consequences, including skin cancers, premature skin aging, and erythema. To mitigate these risks, preventive actions mainly focus on advocating the application of sunscreen lotions and minimizing direct exposure to sunlight. This research study specifically centered on ensulizole (ENS), a prominent ingredient in sunscreens. The objective was to create inclusion complexes (ICs) with Beta-cyclodextrin (B-CD) and its hydroxypropyl derivatives (H-CD). Using phase solubility measurements, we determined that both B-CD and H-CD form 1:1 stoichiometric ICs with ENS. Proton nuclear magnetic resonance spectral (1H NMR) analysis confirmed that the phenyl portion of ENS is encapsulated within the B-CD cavity. Significant changes in surface morphology were observed during the formation of these ICs compared to ENS and CDs alone. Quantum mechanical calculations were employed to further support the formation of ICs by providing energy data. Particularly, the photostability of the ENS:B-CD ICs remained intact for up to four hours of UV exposure, with no significant alterations in the structure of ENS. Furthermore, comprehensive biocompatibility assessments yielded encouraging results, suggesting the potential application of these inclusion complexes in cosmetics as a UVB sunscreen. In summary, our research underscores the successful creation of inclusion complexes characterized by enhanced photostability and safe biocompatibility.

Adenosine/ß-Cyclodextrin-Based Metal-Organic Frameworks as a Potential Material for Cancer Therapy.

Recently, researchers have employed metal-organic frameworks (MOFs) for loading pharmaceutically important substances. MOFs are a novel class of porous class of materials formed by the self-assembly of organic ligands and metal ions, creating a network structure. The current investigation effectively achieves the loading of adenosine (ADN) into a metal-organic framework based on cyclodextrin (CD) using a solvent diffusion method. The composite material, referred to as ADN:ß-CD-K MOFs, is created by loading ADN into beta-cyclodextrin (ß-CD) with the addition of K+ salts. This study delves into the detailed examination of the interaction between ADN and ß-CD in the form of MOFs. The focus is primarily on investigating the hydrogen bonding interaction and energy parameters through the aid of semi-empirical quantum mechanical computations. The analysis of peaks that are associated with the ADN-loaded ICs (inclusion complexes) within the MOFs indicates that ADN becomes incorporated into a partially amorphous state. Observations from SEM images reveal well-defined crystalline structures within the MOFs. Interestingly, when ADN is absent from the MOFs, smaller and irregularly shaped crystals are formed. This could potentially be attributed to the MOF manufacturing process. Furthermore, this study explores the additional cross-linking of ß-CD with K through the coupling of -OH on the ß-CD-K MOFs. The findings corroborate the results obtained from FT-IR analysis, suggesting that ß-CD plays a crucial role as a seed in the creation of ß-CD-K MOFs. Furthermore, the cytotoxicity of the MOFs is assessed in vitro using MDA-MB-231 cells (human breast cancer cells).

Preparation and Characterization of a Nano-Inclusion Complex of Quercetin with ß-Cyclodextrin and Its Potential Activity on Cancer Cells.

Quercetin (QRC), a flavonoid found in foods and plants such as red wine, onions, green tea, apples, and berries, possesses remarkable anti-inflammatory and antioxidant properties. These properties make it effective in combating cancer cells, reducing inflammation, protecting against heart disease, and regulating blood sugar levels. To enhance the potential of inclusion complexes (ICs) containing ß-cyclodextrin (ß-CD) in cancer therapy, they were transformed into nano-inclusion complexes (NICs). In this research, NICs were synthesized using ethanol as a reducing agent in the nanoprecipitation process. By employing FT-IR analysis, it was observed that hydrogen bonds were formed between QRC and ß-CD. Moreover, the IC molecules formed NICs through the aggregation facilitated by intermolecular hydrogen bonds. Proton NMR results further confirmed the occurrence of proton shielding and deshielding subsequent to the formation of NICs. The introduction of ß-CDs led to the development of a distinctive feather-like structure within the NICs. The particle sizes were consistently measured around 200 nm, and both SAED and XRD patterns indicated the absence of crystalline NICs, providing supporting evidence. Through cytotoxicity and fluorescence-assisted cell-sorting analysis, the synthesized NICs showed no significant damage in the cell line of MCF-7. In comparison to QRC alone, the presence of high concentrations of NICs exhibited a lesser degree of toxicity in normal human lung fibroblast MRC-5 cells. Moreover, the individual and combined administration of both low and high concentrations of NICs effectively suppressed the growth of cancer cells (MDA-MB-231). The solubility improvement resulting from the formation of QRC-NICs with ß-CD enhanced the percentage of cell survival for MCF-7 cell types.

Narrative of hazardous chemicals in water: Its potential removal approach and health effects.

H2O is essential for life to exist on earth; it is important to guarantee both the quality and supply of water to satisfy world demand. However, it became contaminated by a number of hazardous, inorganic industrial pollutants, which caused a number of issues like irrigation activities and unsafe human ingestion. Long-term exposure to harmful substances can result in respiratory, immunological, and neurological illnesses, cancer, and problems during pregnancy. Therefore, removing hazardous substances from wastewater and natural water sources is crucial. It is necessary to develop an alternate method that can effectively remove these toxins from water bodies, as conventional methods have several drawbacks. This review primarily aims to achieve the following goals: 1) to discuss the distribution of harmful chemicals: 2) to give specifics on numerous possible strategies for getting rid of hazardous chemicals, and 3) its effects on the environment and consequences for human health have been examined.

Sustainable Synthesis of Bright Fluorescent Nitrogen-Doped Carbon Dots from Terminalia chebula for In Vitro Imaging.

In this study, sustainable, low-cost, and environmentally friendly biomass (Terminalia chebula) was employed as a precursor for the formation of nitrogen-doped carbon dots (N-CDs). The hydrothermally assisted Terminalia chebula fruit-derived N-CDs (TC-CDs) emitted different bright fluorescent colors under various excitation wavelengths. The prepared TC-CDs showed a spherical morphology with a narrow size distribution and excellent water dispensability due to their abundant functionalities, such as oxygen- and nitrogen-bearing molecules on the surfaces of the TC-CDs. Additionally, these TC-CDs exhibited high photostability, good biocompatibility, very low toxicity, and excellent cell permeability against HCT-116 human colon carcinoma cells. The cell viability of HCT-116 human colon carcinoma cells in the presence of TC-CDs aqueous solution was calculated by MTT assay, and cell viability was higher than 95%, even at a higher concentration of 200 µg mL-1 after 24 h incubation time. Finally, the uptake of TC-CDs by HCT-116 human colon carcinoma cells displayed distinguished blue, green, and red colors during in vitro imaging when excited by three filters with different wavelengths under a laser scanning confocal microscope. Thus, TC-CDs could be used as a potential candidate for various biomedical applications. Moreover, the conversion of low-cost/waste natural biomass into products of value promotes the sustainable development of the economy and human society.

A novel and water-soluble material for coronavirus inactivation from oseltamivir in the cavity of methyl and sulfated-ß-cyclodextrins through inclusion complexation.

A potentially active water-soluble anti-viral with lesser toxic material from the Oseltamivir (OTV) has been produced by the sonication method. The formed material has been further characterized by UV-visible, FT-IR, powder XRD, SEM, TGA/DTA, ROESY, XPS, AFM and etc., The results of DFT calculation have proven that inclusion complexes (ICs) are theoretically and energetically more advantageous models and structures have also been proposed based on the results. Analysis of drug release has been carried out at three pH levels, and it is revealed the analysis is most helpful at acidic pH levels for the ICs with S-CD over H-CD. Over OTV without CDs, OTV:S-CD-ICs exhibited a very less cytotoxic ability on cancer cell lines than ICs with M-CD. ICs enhanced the coronavirus inactivation nature of OTV. This study provides for the first time a full characterization of ICs of OTV with CDs and highlights the impact of complexation on pharmacological activity.

Synthesis of Water-Dispersed Sulfobetaine Methacrylate-Iron Oxide Nanoparticle-Coated Graphene Composite by Free Radical Polymerization.

Research on the synthesis of water-soluble polymers has accelerated in recent years, as they are employed in many bio-applications. Herein, the synthesis of poly[2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (PSB) by free radical polymerization in a sonication bath is described. PSB and iron oxide nanoparticles (IONPs) were simultaneously stabilized on the graphene surface. Graphene surfaces with PSB (GPSB) and graphene surfaces with PSB and IONPs (GPSBI) were prepared. Since PSB is a water-soluble polymer, the hydrophobic nature of graphene surfaces converts to hydrophilic nature. Subsequently, the prepared graphene composites, GPSB and GPSBI, were well-dispersed in water. The preparation of GPSB and GPSBI was confirmed by X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The impacts of PSB and IONPs on the graphene surfaces were studied systematically.

Phytochemical Screening and Bioactivity Studies of Endophytes Cladosporium sp. Isolated from the Endangered Plant Vateria Indica Using In Silico and In Vitro Analysis.

Vateria indica is persistent tree used in Unani sources for the medication and classified as critically endangered. Thus, endophytes for alternative methods to explore these endangered Plants having rich source pharmaceuticals' active molecules for drug development and production. Endophytes comprises unexplored microbes as a potential source of rich pharmaceutically bioactive compounds attributable to their relationship with the host. In the current study, we have isolated endophyte fungi Cladosporium from the plant Vateria indica and performed phytochemical screening of its ethanolic extract to detect the phytochemicals using thin layer chromatography (TLC), gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), UV-visible spectrophotometry (UV-VIS), and Fourier transform infrared spectroscopy (FTIR). GC-MS analysis revealed the presence of an anticancer compound hydroxymethyl colchicine, antioxidant compound benzoic acid, and antimicrobial 2-(4-chlorophenoxy)-5-nitro in endophyte fungal extract of plant Vateria indica. Moreover, in silico analysis of bioactive compounds identified by GC-MS analysis using the Autodock Vina and SwissADME confirmed excellent anticancer activity methanone, [4-amino-2-[(phenylmethyl) amino]-5-thiazolyl] (4-fluorophenyl)- and hydroxymethyl colchicine against 6VO4 (Bfl-1 protein) as per Lipinski rule. Furthermore, we also demonstrated the excellent antioxidant of endophytic extract compared to plant extract by DPPH and ABTS assay, as well as antimicrobial activity against both Gram (+ ve) and Gram (- ve) bacteria. Moreover, the endophytic extract also showed its antimitotic activity with a mitotic index of 65.32, greater than the plant extract of 32.56 at 10 mg/ml. Thus endophytic fungi Cladosporium species isolated from plant Vateria indica might be used as a potential source for phytochemical anticancer hydroxymethyl colchicine, an antioxidant benzoic acid, and antimicrobial 2-(4-chlorophenoxy)-5-nitro.

Isolation and Phytochemical Screening of Endophytic Fungi Isolated from Medicinal Plant Mappia foetida and Evaluation of Its In Vitro Cytotoxicity in Cancer.

Isolated endophyte fungi from Mappia foetida have been explored as a potential source for the mass production of anticancer drug lead compounds in the current study. Since medical plants are not feasible economically for mass production of bioactive pharmaceutical important molecules using plant tissue culture due to factors like media design and fungal contamination, endophyte fungal mass culture have been an alternative for the relatively easy and inexpensive production. Two endophytic fungi isolated, Alternaria alternata and Fusarium species were mass cultured and their prepared alcoholic extract subjected to standard procedures to identify the phytochemical screening by gas chromatography-mass spectrometry (GCMS), high-performance liquid chromatography (HPLC), UV visible spectrophotometry (UV-VIS), and Fourier transform infrared spectroscopy (FTIR). GC-MS analysis revealed the presence of three major compounds in the extracts. The phytochemical screening confirmed the presence of an anticancer compound (camptothecin) in their extract. Moreover, the dose-dependent anticancer activity of ethanol extract was demonstrated against cervical carcinoma (HeLa), breast carcinoma (MCF-7), non-small cell lung carcinoma (H1975), and hepatocellular carcinoma cell line (Hep G2) by MTT assay where doxorubicin was used as the positive control. Furthermore, the microscopic examination also confirmed the cytotoxic effect of extract of endophytic fungi Alternaria alternata and Fusarium species against tested cancer cells. Hence, endophytic fungi Alternaria alternata and Fusarium species might be exploited for mass production of phytochemicals having anticancer activity.

In situ synthesis and characterization of colloidal AuNPs capped nano-chitosan containing poly(2,5-dimethoxyaniline) nanocomposites for biomedical applications.

Herein, we have successfully synthesized a novel nCS-PDMA/AuNPs nanocomposite based on nano-chitosan containing poly(2,5-dimethoxyaniline) capped gold nanoparticle in situ synthesis is reported. The AuNPs were synthesized using the green method without using any harmful chemicals, reducing and stabilizing agents to generate AuNPs, is not needed because these roles are played by nCS. The synthesized nCS-PDMA/AuNPs nanocomposite were characterized by UV-Vis, FT-IR, XRD, SEM, and TEM analysis. The polydispersed nCS-PDMA/AuNPs nanocomposite was observed approximately 25 nm. Furthermore, nCS-PDMA/AuNPs nanocomposite was showed significant antibacterial activity against S. aureus and E. coli. The nCS-PDMA/AuNPs nanocomposite showed strong antioxidant activity by inhibiting the DPPH radicals. In addition, the cytotoxicity of nCS-PDMA/AuNPs nanocomposite was tested in HeLa cells and found to be high toxicity than nCS-PDMA. This work suggests that green synthesized nCS-PDMA/AuNPs nanocomposite may be utilized as an effective antibacterial, antioxidant, and anticancer activity.[Figure: see text]Research highlightsnCS-PDMA capped gold nanoparticles (nCS-PDMA/AuNPs) were prepared.Physical characterization of nCS-PDMA/AuNPs by UV-vis, FTIR, XRD, SEM, and TEM.nCS-PDMA/AuNPs displayed promising inhibitory activity against both bacteria.nCS-PDMA/AuNPs showed significant DPPH radical scavenging activities.nCS-PDMA/AuNPs showed an excellent anticancer activity against HeLa cells.

Supramolecular nanogels based on gelatin-cyclodextrin-stabilized silver nanocomposites with antibacterial and anticancer properties.

An effective method for reducing silver ions using gelatin (Gel) and 2-hydroxypropyl-ß-cyclodextrin (HPCD) hydrogels, which stabilize silver at various concentrations is described. The formation of AgNPs in solution, as well as Gel-HPCD nanogels, is confirmed by the surface plasmon resonance (SPR) band at 420-440 nm in the UV-Vis spectrum. The resulting Gel-HPCD and Gel-HPCD/AgNPs composites are characterized using various techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), and thermogravimetric analysis (TGA). SEM images showed that the porous structure and the AgNPs are homogeneously dispersed throughout the Gel-HPCD/AgNP composites network. The AgNPs in the Gel-HPCD/AgNPs composite is crystalline, with spherical particles having an average size of 7.0 ± 2.5 nm, as determined by TEM. The Gel-HPCD/AgNPs composites are strongly effective against both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. The assembled antibacterial Gel-HPCD/AgNPs composites are also assessed for their cytotoxic and anticancer activities using HCT-116 cancer cells. The results suggest that Gel-HPCD/AgNPs composites could be used as effective therapeutics in the future in tissue engineering applications, as their bactericidal properties and low toxicity make them ideal for clinical use.

Tunable fluorescent carbon dots from biowaste as fluorescence ink and imaging human normal and cancer cells.

Growing global biowaste and its environmental issues challenge the need for converting biowastes into a beneficial product. Among the biowaste, here kiwi fruit (Actinidia Deliciosa) peels are considered for the preparation of carbon dots (CDs). Using a green one-pot hydrothermal-carbonization method, kiwi fruit peels were effectively converted into valuable kiwi fruit peel carbon dots (KFP-CDs). The morphology, physio-chemical and optical properties of as-synthesized KFP-CDs were analyzed using various analytical techniques such as X-ray powder diffraction, Raman spectroscopy, attenuated total reflection-Fourier transform infrared spectroscopy, field emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, Ultraviolet-visible, and fluorescence spectroscopy. The KFP-CDs revealed a homogeneous spherical shape, monodispersed with an average size of 5 nm. The characterization confirms that KFP-CDs have functional groups such as -CN, -COOH, and -OH which are responsible for the easy dispersion of KFP-CDs in aqueous media. Without any preprocessing, KFP-CDs exhibit strong fluorescence upon exposure to UV light. Further, KFP-CDs displayed excitation-dependent fluorescence emission with a good quantum yield of about 18%. Thus by considering the excellent properties of KFP-CDs, KFP-CDs were used as fluorescent ink for drawing and writing without any capping/passivation agent. The pictures and words were instantaneously viewed when exposed to UV light. In addition, KFP-CDs tested for cell imaging in four human cell lines (normal and cancer cells) bestowed excellent biocompatibility and low cytotoxicity, which is important for the safe and long-term development of cellular imaging. The findings imply that KFP-CDs can be utilized as a cell labeling agent for mesenchymal stem cells, breast cancer, and thyroid cancer cells in vitro imaging. Thus, these observations revealed that investigating sustainable resource-based CDs can open up new avenues for tackling environmental issues.

Rapid detection of silver ions based on luminescent carbon nanodots for multicolor patterning, smartphone sensors, and bioimaging applications.

Photoluminescent nitrogen and sulfur co-doped carbon nanodots (N,S-CNDs) were prepared via single-step hydrothermal carbonization using 2,4-diaminobenzenesulfonic acid (2,4-DABSA) as the sole precursor. The synthesized N,S-CNDs are easily dispersed in aqueous solution and have an average particle size of 5.0 ± 0.2 nm, showing a high quantum yield of 23.1% with excellent stability. The surface states of the N,S-CNDs were confirmed by Fourier-transform infrared spectroscopy, powder X-ray diffractometry, Raman spectroscopy, and X-ray photoelectron spectroscopy techniques. These N,S-CNDs were applied for the rapid visual sensing detection of Ag+ ions, which can be identified by their photoluminescent color change under ultraviolet (UV) light illumination at 365 nm within 5 s. Furthermore, a linear correlation coefficient between P0/P and Ag+ ions was observed in the linear range of 0-1.2 µM with a detection limit of 7.88 nM. The proposed method was successfully used for the sensitive detection of Ag+ ions in real samples with satisfactory recoveries and relative standard deviation. The photoluminescence properties of N,S-CND and N,S-CNDs/Ag+ aqueous solutions were demonstrated by their invisible inks that can only be seen when irradiated with UV light. The RGB values of N,S-CND and N,S-CNDs/Ag+ aqueous solutions were measured using a color selector smartphone application. In addition, N,S-CND and N,S-CNDs/Ag+ aqueous solutions were further used for the multicolor imaging of HCT-116 cancer cells due to the low toxicity of N,S-CNDs.

Sensitive and selective fluorometric determination of DNA by using layered hexagonal nanosheets of a covalent organic framework prepared from p-phenylenediamine and benzene-1,3,5-tricarboxaldehyde.

A modified method is described for the preparation of amino-functionalized covalent organic framework nanosheets (COF-NSs). These consist of hexagonal layered sheets and were prepared from commercially available starting materials (p-phenylenediamine and benzene-1,3,5-tricarboxaldehyde). The interlayer stacking interactions between the ultra-thin COF-NSs became weak because the π stacking is destroyed by sonication. This result in the exfoliation of COF-NSs. As an application, the COF-NSs used for sensitive and selective fluorometric determination of DNA. To reach this goal, H1 and H2 hairpin-like DNA probes were chosen; H1 used Texas Red-labeled dye as a fluorescent probe. The addition of the COF-NSs, the hairpin probes was adsorbed onto the porous surface of the COFNSs. The π stacking and hydrogen-bond interactions between COFNSs and nucleic acid quench the fluorescence of the Texas red-labeled probe. The target DNA enables the recovery of the quenched fluorescence of the Texas red-labelled probe by triggering an inter-chain hybridization within hairpin probes. This results in a weaker interaction of double-stranded DNA (dsDNA) with the COFNSs. Consequently, the dsDNA detaches from the COFNSs, thereby recovering the dye's fluorescence (excitation/emission maxima at 590/612 nm) with increasing target DNA concentration. The findings were applied to design a method for the determination of DNA that has a 2 pM detection limit. This is significantly lower than the limit of detection reported previously for 2D nanomaterial-based fluorometric DNA assays. Graphical abstractSchematic representation of 2D-covalent organic framework nanosheets (COF-NSs) probe act as a quencher allowing the highly sensitive and selective fluorescence turn-on detection for biomolecules. Here the H1 H2 are hairpin DNAs. H1 is associated with the fluorescent tag (red circle), while the "fluorescence off" state it denoted as a black circle.

Enhanced solubility of guanosine by inclusion complexes with cyclodextrin derivatives: Preparation, characterization, and evaluation.

This study improves the water solubility and cellular uptake of guanosine (GuN) through an inclusion complexation with cyclodextrin derivatives (CDs), namely ß-cyclodextrin (ß-CD), hydroxypropyl-ß-cyclodextrin (HP-ß-CD), and sulfobutyl ether-ß-cyclodextrin (SBE-ß-CD). Inclusion complexes of GuN and CDs are synthesized in a 1:1 stoichiometric ratio with binding constants calculated using the Benesi-Hildebrand method. Characterizations of the prepared solid complexes using FTIR, XRD, TGA-DSC, and SEM indicate that GuN is found inside the cavity of the CDs. Moreover, in silico molecular modeling analysis identifies the most favorable binding interactions of GuN deeply encapsulated in the hydrophobic cavities of the CDs, as validated by PatchDock and FireDock servers. In addition, human breast cancer MCF-7 cell activity indicates that the SBE-ß-CD:GuN complex displays better cell viability and cellular uptake than GuN or other inclusion complexes of ß-CD:GuN and HP-ß-CD:GuN.

Enhanced electrochemical performance of nickel-cobalt-oxide@reduced graphene oxide//activated carbon asymmetric supercapacitors by the addition of a redox-active electrolyte.

Supercapacitors are an emerging energy-storage system with a wide range of potential applications. In this study, highly porous nickel-cobalt-oxide@reduced graphene oxide (Ni-Co-O@RGO-s) nanosheets were synthesized as an active material for supercapacitors using a surfactant-assisted microwave irradiation technique. The RGO-modified nanocomposite showed a larger specific area, better conductivity, and lower resistivity than the unmodified nanocomposite because the RGO facilitated faster ion diffusion/transport for improved redox activity. The synergistic effect of Ni-Co-O@RGO-s resulted in a high capacitance of 1903Fg-1 (at 0.8Ag-1) in a mixed KOH/redox active K3Fe(CN)6 electrolyte. The asymmetric Ni-Co-O@RGO-s//AC supercapacitor device yielded a high energy density and power density of 39Whkg-1 and 7500Wkg-1, respectively. The porous structure and combination of redox couples from both the electrode and electrolyte provided a highly synergistic effect, which improved the performance of the supercapacitor device.

Degradation of organic pollutants by bio-inspired rectangular and hexagonal titanium dioxide nanostructures.

Dyes are used in textile, printing, leather, pharmaceutical, food and cosmetic industries. Dyes add color and pattern to materials. The presence of even very low concentration of dyes/dyes degradation products in effluent is highly toxic to humans and aquatic organisms. It is important to remove these dye degradation pollutants from the industrial effluents before their disposal. In recent years nanoparticles have been used for the removal of dyes from industrial waste water. Titanium dioxide nanostructures (TiO2 NS) were synthesized via a one-step facile green process. The formation of TiO2 NS was confirmed by Fourier transform infrared (FTIR) and Raman spectroscopy. Anatase (~76%) and rutile (~24%) phases were present, as determined by X-ray diffraction (XRD) analysis. X-ray photoelectron spectroscopy (XPS) was used to study the surface oxidation states of the TiO2 NS. High resolution transmission electron microscopy (HR-TEM) images revealed that the samples had hexagonal and rectangular morphologies, with diameters of ~24-32nm. The TiO2 NS were used to evaluate the photocatalytic activities of methylene blue (MB) and malachite green (MG) dyes under UV light and in dark conditions. After 60min of UV irradiation, nearly 71% of the MB and 78% of the MG was decolorized in the presence of as-synthesized TiO2 NPs.

Biological and catalytic applications of green synthesized fluorescent N-doped carbon dots using Hylocereus undatus.

In this work, a simple hydrothermal route for the synthesis of fluorescent nitrogen doped carbon dots (N-CDs) is reported. The Hylocereus undatus (H. undatus) extract and aqueous ammonia are used as carbon and nitrogen source, respectively. The optical properties of synthesized N-CDs are analyzed using UV-Visible (UV-Vis) and fluorescence spectroscopy. The surface morphology, elemental composition, crystallinity and functional groups present in the N-CDs are examined using high resolution transmission electron microscopy (HR-TEM) with energy dispersive spectroscopy (EDS), selected area electron diffraction (SAED), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy, respectively. The synthesized N-CDs emit strong blue fluorescence at 400nm under the excitation of 320nm. Further, the excitation dependent emission properties are also observed from the fluorescence of synthesized N-CDs. The HR-TEM results reveal that synthesized N-CDs are in spherical shape with average diameter of 2.5nm. The XRD pattern exhibits, the graphitic nature of synthesized N-CDs. The doping of nitrogen is confirmed from the EDS and FT-IR studies. The cytotoxicity and biocompatibility of N-CDs are evaluated through MTT assay on L-929 (Lymphoblastoid-929) and MCF-7 (Michigan Cancer Foundation-7) cells. The results indicate that the fluorescent N-CDs show less cytotoxicity and good biocompatibility on both L-929 and MCF-7 cells. Moreover, the N-CDs show excellent catalytic activity towards the reduction of methylene blue by sodium borohydride.

One-pot construction of sterically challenging and diverse polyarylphenols via transition-metal-free benzannulation and their potent in vitro antioxidant activity.

This paper reports the novel and efficient one-pot synthesis of highly functionalized polyarylphenols from readily available 1,3-diarylpropan-2-ones and chalcones or cinnamaldehyde derivatives via benzannulation under transition-metal-free and aerobic conditions. This benzannulation proceeds through cascade Michael addition/intramolecular aldol/tautomerization/oxidation. This protocol produces various tetra- and tri-aryl substituted phenols in moderate to good yield. The synthesized compounds exhibited potent antioxidant activities compared to the standard BHT.