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In the present article we describe a facile biosynthetic method for the silver nanoparticles highlighting myconanotechnology and its antimicrobial efficacy. The nanoparticles were characterized using UV-vis spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and fourior transform infrared (FTIR) spectroscopy. These methods allow validating the spherical nature of the produced nanoparticles ranging from 30 nm to ∼90 nm in size. The crystallinity of the nanoparticles was confirmed by XRD. The probable mechanistic aspect for the mycogenesis of the silver nanoparticles are also evaluated which would facilitate for several industrial applications based on potential antimicrobials. [ABSTRACT FROM AUTHOR]

In recent years, rapid technological advancements have led to the development of nanoscale device components, advanced sensors, and novel biomimetic materials. Potential negative impacts of nanomaterials are sometimes overlooked during the discovery phase of research. The use of green chemistry can however enhance nanoscience by maximizing safety and efficiency while minimizing the environmental and societal impacts of nanomaterials. Here we report extracellular mycosynthesis of silver nanoparticles by Alternaria alternata. The fungal biomass when exposed to aqueous silver nitrate solution leads to the formation of silver nanoparticles extracellularly. Change in colour of silver nitrate solution to brown signifies the development of silver nanoparticles. UV-Visible spectrum of the aqueous medium containing silver ion showed a peak at 420 nm corresponding to the plasmon absorbance of silver nanoparticles. Agglomeration status was confirmed by Dynamic Light Scattering experiments. Atomic Force Microscopy and Transmission Electron Microscopy explained the formation of well-dispersed silver nanoparticles in the range of 20-45 nm. X-ray Diffraction spectrum of the silver nanoparticles exhibited 20 values corresponding to the silver nanoparticles. Fourier Transform Infrared Spectroscopy confirmed the presence of a protein shell outside the nanoparticles. In this study, mycosynthesized nanoparticles were also evaluated for DNA damaging potential in human lymphocytes using comet assay. [ABSTRACT FROM AUTHOR]

While the terminally protected tripeptide Boc-Phe-Gly-m-ABA-OMe I (m-ABA, meta-amino benzoic acid) is an excellent gelator of aromatic organic solvents, another similar tripeptide Boc-Leu-Gly-m-ABA-OMe II, where the Phe residue of peptide I is replaced by Leu, cannot form gels with the same solvents. The morphology of the gels of peptide I, characterised by the field-emission scanning electron microscopy and high-resolution transmission electron microscopy, reveals the formation of nanofibrous networks which are known to encapsulate solvent molecules to form gels. The wide-angle X-ray scattering studies of the gels suggest the β-sheet-mediated self-assembly of peptide I in the formation of a nanofibrous network, where π-stacking interactions of Phe play an important role in the self-assembly and gel formation. The dried gel of peptide I observed between crossed polarisers after binding with a physiological dye, Congo red, shows a bluish-green birefringence, a characteristic of amyloid fibrils. [ABSTRACT FROM AUTHOR]

Anticoagulants are recommended for the prevention and treatment of venous thromboembolism (VTE). The new anticoagulants which target specific factors in the coagulation cascade offer the advantage that they can be administered orally. These drugs seek to offer safe anticoagulation without the need for regular monitoring and frequent dose adjustment. Some of these newer drugs are in the advanced stages of clinical trials or have already completed them and thereby aim to provide more options in the management of thromboembolism. In the present review we discuss the currently available evidence supporting the use of these new anticoagulants, in particular rivaroxaban. [ABSTRACT FROM AUTHOR]

Background: The incidence and mortality of hepatocellular cancer (HCC) complicating alcoholic and non-alcoholic fatty liver diseases (ALD and NAFLD) is rising in western societies. Despite knowing the at risk populations for HCC development, the lack of sensitive and specific means of surveillance hampers disease detection at curable stages. The most widely used serum HCC marker is alpha-fetoprotein (AFP), while PIVKA-II, glypican-3 (GP3) and Squamous Cell Carcinoma Antigen -1 (SCCA-1) have been proposed as new biomarkers. Assessment of these HCC biomarkers has largely been performed in patients with viral hepatitis. We conducted a cross sectional study assessing the value of these serum proteins, as well a novel candidate biomarker - follistatin -- in patients with HCC arising on a background of ALD or NAFLD. Methods: Pre-treatment serum samples from 50 patients with HCC arising on a background of ALD (n = 31) or NAFLD (n = 19) were assessed by specific ELISA assay for PIVKAII, Glypican-3, SCCA-1 and Follistatin. Results were compared and contrasted with a control patient group with biopsy proven steatohepatitis-related cirrhosis (n = 41). The diagnostic accuracy of each of the candidate biomarkers was evaluated using receiver operating characteristic (ROC) curve analysis, reporting the area under the curve (AUC) and its 95% confidence interval (CI). Performance was compared to that of the established biomarker, AFP. Results: Serum levels of all proteins were assessed by specific ELISA assays. GP3, SCCA-1 and follistatin had no HCC surveillance benefit in these patients. AFP and PIVKAII were superior to the other markers, particularly in combination. [ABSTRACT FROM AUTHOR]

Type 2 diabetes mellitus (T2DM) predominantly considered a metabolic disease is now being considered an inflammatory disease as well due to the involvement of meta-inflammation. Obesity-induced adipose tissue inflammation (ATI) is one of the earliest phenomena in the case of meta-inflammation, leading to the advent of insulin resistance (IR) and T2DM. The key events of ATI are orchestrated by macrophages, which aggravate the inflammatory state in the tissue upon activation, ultimately leading to systemic chronic low-grade inflammation and Non-Alcoholic Steatohepatitis (NASH) through the involvement of proinflammatory cytokines. The CD44 receptor on macrophages is overexpressed in ATI, NASH, and IR. Therefore, we developed a CD44 targeted Hyaluronic Acid functionalized Graphene Oxide Quantum Dots (GOQD-HA) nanocomposite for tissue-specific delivery of metformin. Metformin-loaded GOQD-HA (GOQD-HA-Met) successfully downregulated the expression of proinflammatory cytokines and restored antioxidant status at lower doses than free metformin in both palmitic acid-induced RAW264.7 cells and diet induced obese mice. Our study revealed that the GOQD-HA nanocarrier enhanced the efficacy of Metformin primarily by acting as a therapeutic agent apart from being a drug delivery platform. The therapeutic properties of GOQD-HA stem from both HA and GOQD having anti-inflammatory and antioxidant properties respectively. This study unravels the function of GOQD-HA as a targeted drug delivery option for metformin in meta-inflammation where the nanocarrier itself acts as a therapeutic agent. [ABSTRACT FROM AUTHOR]

Trichobezoar are foreign bodies formed from undigested hairs that accumulate in the gastrointestinal tract and cause obstruction. Trichobezoar are usually found in the stomach but when the tail of the bezoar extends into the small intestine it is referred to as Rapunzel syndrome. Patients are usually females and have a history of psychiatric illness. However, in this study, we present two cases of Rapunzel syndrome in adult male patients that were managed with surgery. Trichobezoar should be considered in all patients with a history of psychiatric illness presenting with abdominal symptoms regardless of gender. [ABSTRACT FROM AUTHOR]

In this study, we have designed and assessed a Ketorolac tromethamine (KT) based thermally responsive in situocular gelling system. These gelling systems consist of a thermally responsive in situ gelling polymer, poloxamer 407 (PM) and different molecular weight of poly (vinyl alcohol) (PVA) as release retardant. The formulations were analyzed for sol‐gel transition temperature, gelling aptitude, viscosity and rheological studies, gel morphology study, gel dissolution property and in vitro drug release study. FTIR spectral analysis was performed to explore any polymer‐polymer or drug‐polymer association. In comparison to commercially available drugs, the new formulations present a longer‐lasting drug release profile. [ABSTRACT FROM AUTHOR]

Diethyl chlorophosphate (DCP) has similar reactivity to sarin, which is widely known as a nerve agent that is often used in terrorist attacks. As DCP lacks high toxicity, it can be used as a model compound for sarin detection. Besides their use as chemical warfare agents (CWAs), organophosphorus compounds (OPs) also have greater implications for human health. To maintain the balance in global security the first and most in demand work is to establish efficient detection methods for monitoring CWAs. The work presented here reports a benzothiazole-based fluorescent chemodosimeter (BZ-DAM) for the fluorogenic detection of DCP via the ESIPT assisted ICT mechanism. The benzothiazole unit serves as a fluorophore, whereas the phenolic and imine groups act as a recognition unit for DCP. In this mechanistic path, the phenol group in BZ-DAM is phosphoesterified by DCP, which leads to a significant fluorescence change and assists the hydrolysis of the aldemine of BZ-DAM. The detection limit was found to be 0.43 μM by the fluorescence method. BZ-DAM is also stable in biological mediums and a physiological pH range and can be successfully used to detect intracellular DCP in living cells. Scanning electron microscopy (SEM) studies of a polycaprolactone (PCL)-BZ-DAM composite also revealed partial deformation of the surface of the nanomaterials upon the adsorption of DCP, indicating a DCP-mediated chemical transformation. [ABSTRACT FROM AUTHOR]

Over the past few years, there is a drive toward the fabrication and application of bio-based non-cytotoxic drug carriers. Cellulose nanocrystals (CNCs) have gotten immense research attention as a promising bioderived material in the biomedical field due to its remarkable properties. The delivery of analgesic and anti-inflammatory drug, ketorolac tromethamine (KT) by transdermal route is stipulated herewith to fabricate suitable transdermal therapeutic systems. We have synthesized CNCs from jute fibers and aim to develop a non-cytotoxic polymer-based bionanocomposites (BNCs) transdermal patch, formulated with methylcellulose (MC), chitosan (CH), along with exploration of CNCs for sustained delivery of KT, where CNCs act as nanofiller and elegant nanocarrier. CNCs reinforced MCCH blends were prepared via the solvent evaporation technique. The chemical structure, morphology, and thermal stability of the prepared bionanocomposites formulations were studied by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), TGA, DSC, DMA, and SEM. The In vitro drug release studies were executed using Franz diffusion cells. The BNC patches showed in-vitro cytocompatibility and the drug release study revealed that BNC containing 1 wt% CNCs presented the best-sustained drug release profile. The bioderived CNCs appear to enhance the BNCs drug's bioavailability, which could have a broad prospect for TDD applications. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, harvested mushroom substrate (HMS) has been explored for the first time through a comprehensive optimization study for the green synthesis of silver nanoparticles (AgNPs). A multiple response central composite design with three parameters: pH of the reaction mixture, temperature, and incubation period at three distinct levels was employed in the optimization study. The particle size of AgNPs, UV absorbance, and the percentage of Ag/Cl elemental ratio were considered as the response parameters. For each response variable examined the model used was found to be significant (P < 0.05). The ideal conditions were: pH 8.9, a temperature of 59.4 °C, and an incubation period of 48.5 h. The UV–visible spectra of AgNPs indicated that the absorption maxima for AgNP–3 were 414 nm, 420 for AgNPs–2, and 457 for AgNPs-1. The XRD analysis of AgNPs-3 and AgNPs-2 show a large diffraction peak at ∼38.2°, ∼44.2°, ∼64.4°, and ∼77.4°, respectively, which relate to the planes of polycrystalline face-centered cubic (fcc) silver. Additionally, the XRD result of AgNPs–1, reveals diffraction characteristics of AgCl planes (111, 200, 220, 311, 222, and 400). The TEM investigations indicated that the smallest particles were synthesized at pH 9 with average diameters of 35 ± 6 nm (AgNPs–3). The zeta potentials of the AgNPs are −36 (AgNPs–3), −28 (AgNPs–2), and −19 (AgNPs–1) mV, respectively. The distinct IR peak at 3400, 1634, and 1383 cm−1 indicated the typical vibration of phenols, proteins, and alkaloids, respectively. The AgNPs were further evaluated against gram (+) strain Bacillus subtilis (MTCC 736) and gram (−) strain Escherichia coli (MTCC 68). All of the NPs tested positive for antibacterial activity against both bacterial strains. The study makes a sustainable alternative to disposing of HMS to achieve the Sustainable Development Goals (SDGs). [Display omitted] • Harvested Mushroom Substrate utilized for the synthesis of silver nanoparticles. • The synthesis process was further optimized with central composite design. • PH > 9 yielded better morphology of synthesized silver nanoparticles. • The average size of the silver nanoparticles at pH > 9 was 35 ± 6 nm. • Highest bactericidal activity of silver nanoparticles were observed in 6.96 ± 0.03 ppm. [ABSTRACT FROM AUTHOR]

AIM: A safe injection does no harm; but unsafe injection practices are a plague of many health systems. The most affected category of health care providers are the nursing personnel. METHOD: This hospital based cross sectional observational study was conducted among 80 nurses involved in patient care to assess their knowledge regarding safe injection practices and to assess certain aspects of their practice while administering injection and disposal of the disposables. RESULTS: About 52.5% subjects were protected by hepatitis B vaccination. During the last 6 months, 6.3% nurses got accidental needle stick injury three or more times. About 12.5% study subjects washed their hands with soap and water before administering injection. About 60% of the nursing personnel maintained correct procedure during giving injection; while sterile gloves were used only by 3.7% nurses. During disposal of used needles, in 57.5% cases hub cutters were used, while needles were recapped in 42.5% of cases. Used syringes were disposed off correctly in 41.2% of cases. CONCLUSION: There is a need to educate, train and motivate service providers in proper method of handling injection equipments. A local policy and surveillance programme based on the WHO guidelines might be helpful in this situation. [ABSTRACT FROM AUTHOR]

Abstract: Extremely fast release of diltiazem hydrochloride (water soluble, anti anginal drug used to treat chest pain) together with its faster erosion has been the primary problem in conventional oral therapy. It has been addressed in this paper by encapsulating the drug in electron beam irradiated various poly (vinyl alcohol) hydrogel membranes and delivering it through transdermal route. Results show excellent control over the release of diltiazem hydrochloride through these membranes subject to their physico-mechanicals. [Copyright &y& Elsevier]

Aqueous nanosilica sol (particle size range: 9-13 nm, pH: 9.0) was added at various low concentration range (0.5-2 wt.%) into aqueous poly (vinyl alcohol) (PVA) of different molecular weight (98% hydrolyzed, 20 wt.%) (pH: 5.0) at room temperature under constant stirring to synthesize organic-inorganic hybrid hydrogels in presence of sodium lauryl sulphate as a silica dispersant. Buffer tablets were added to arrest the pH at 9.0 (to prevent any silica aggregation due to change in pH). The resultant hybrids were cast on Teflon sheets and dried in an oven at 50°C to drive out all the unbound water. Those films were then subjected to freese-thaw treatment continuously for 5 h. The freese-thawed films appeared opaque. The swelling-de swelling experiments with the hydrogels were carried out in distilled water at room temperature and consequently allowed to de-swell naturally. Those observations were correlated with the microstructures of the hybrid hydrogels. [ABSTRACT FROM AUTHOR]

The aim of the present study was the development of thermo-sensitive in-situ gels for in-vitro evaluation of ophthalmic delivery systems of ketorolac tromethamine (KT), based on methylcellulose (MC) in combination with hydroxypropylmethyl cellulose (HPMC). The gel temperature of 1% MC solutionwas observed at 60°C. It was found that 6% oral rehydration salt without dextrose (ORS) was capable to reduce the gel temperature below physiological temperature. HPMC was added to increase viscosity and drug release time. The results indicated a large increase in viscosity at 37°C with addition of HPMC whch provided sustained release of the drug over a 4h period. From in-vitro release studies, it could be concluded that the developed systems were thus a better alternative to conventional eye drops. [ABSTRACT FROM AUTHOR]

The aim of the present study was the development of thermo-sensitive in-situ gels for in-vitro evaluation of ophthalmic delivery systems of ketorolac tromethamine (KT), based on methylcellulose (MC) in combination with hydroxypropylmethyl cellulose (HPMC). The gel temperature of 1% MC solution was observed at 60°C. It was found that 6% oral rehydration salt without dextrose (ORS) was capable to reduce the gel temperature below physiological temperature. HPMC was added to increase viscosity and drug release time. The results indicated a large increase in viscosity at 37°C with addition of HPMC whch provided sustained release of the drug over a 4h period. From in-vitro release studies, it could be concluded that the developed systems were thus a better alternative to conventional eye drops. [ABSTRACT FROM AUTHOR]

Here, development of some Ag2S mixed chalcogenide glassy systems has been discussed in the light of DC conductivity model and variable range hopping model. X-ray diffraction (XRD) pattern has been collected to explore microstructure of them. Various nanophases such as Ag2Se and GeSe2 have been pointed out from XRD studies. Defects have been identified in the form of dislocation, and their roles in the electrical transport properties have been established. FE-SEM micrographs exhibit their amorphous nature with distributed sharper crystal-like structure. Optical phonon frequency may cause to enhance the structural vibrations by means of increasing DC electrical conductivity. Significant enhancement of density of states near Fermi level at low and high temperatures have been explained. Present glassy structure is expected to expand to reduce the scattering cross-section for getting higher values of N(EF) at higher temperature up to a great extent. [ABSTRACT FROM AUTHOR]

Co-RGO nanocomposites are known to show interesting properties suitable for various applications. However, its use in the vital field of plasmonic nanocomposites is restricted as Co nanoparticles have high damping and dielectric loss. In this work, we have demonstrated a simple synthetic way to produce water-dispersible shape variant Co-reduced graphene oxide (RGO) hybrid nanocomposites, which can overcome those barriers and delineate two plasmonic peaks. Prepared multifunctional optical materials show both UV and visible range of plasmonic responses of Co NPs. While the single domain Co NPs show spin-up channel based sharp plasmonic peak in the UV range, the larger particles introduce shape-dependent enhancement of the excitation independent blue photoluminescence of graphene oxide (GO). Usually, due to their different size regime, it is not possible to see both UV and visible range plasmonic responses of Co NPs simultaneously. The variation of the Co particle size was deliberate to achieve multifunctionality. Shape-induced enhancement in the PL spectrum and decoration of plasmonic metal NPs are achieved. TEM micrographs of hybrids confirm the decoration of different shapes of Co nanoparticles on RGO sheets. The size distribution of the nanoparticles in the composites was quantified using two complementary techniques; SAXS/SANS and TEM. Scattering revealed the alteration of RGO agglomeration with the incorporation of differently shaped nanoparticles. Prepared hybrid nanocomposite having both the responses could be promising in magnetoplasmonics, GMR- and doping-based optoelectronics. [ABSTRACT FROM AUTHOR]

Lead-free halide perovskites nanocrystals (NCs) have been widely used not only in the field of optoelectronics but also in energy storage applications like electrochemical supercapacitors, which could replace electrochemical batteries due to their high power density and long cycle life. The low energy density of supercapacitors is one of the main reasons why they have limited commercial applications. Herein, we have reported synthesis of 3D methylammonium tin chloride perovskite (MASnCl 3) nanocrystals (NCs) via a ligand-assisted re-precipitation process (LARP) and determined its performance as an electrochemical supercapacitor. The formation of MASnCl 3 NCs is confirmed by different characterization tools. The supercapacitor performances of the synthesized NCs are studied by using three-electrode electrochemical measurements. The maximum specific capacitance, energy density, and power density are found to be 2050 Fg−1, 12 kWKg−1, and 102 WhKg−1, respectively. The charge storage mechanism is estimated from the power law equation by studying the diffusion-limited and capacitive processes and it has been found that the capacitance is 94.16 % capacitive to 5.84 % diffusive in nature. The supercapacitor performance of the synthesized MASnCl 3 NCs are studied by fabricating a metal coin-based two-electrode system in which PVA-H 2 SO 4 as solid state electrolyte and NCs act as an active material. The device has retained 80.7 % of its initial specific capacitance value even after 1000 GCD cycles. Interestingly, the developed device showed almost similar gravimetric capacitance value and is enabled to glow a light emitting diode (LED) smoothly. [Display omitted] • Synthesis of lead free tin halide perovskite via LARP process. • The sheet-like perovskite exhibit enhanced electrochemical property. • Maximum C sp and energy density is found to be 2050 Fg−1 & 12 kWKg−1, respectively. • The charge storage mechanism indicates its 94.16 % capacitive in nature. • The developed device is used to power up for glowing of an LED. [ABSTRACT FROM AUTHOR]

Herein, the potential impact of tamarind seed polysaccharide (TSP) on the gelation nature and in vitro release of a particular drug, pilocarpine hydrochloride, from different poloxamer 407-based ophthalmic formulations were evaluated. The combination of TSP (0.5–1.5 wt%) and 18 wt% poloxamer (PM) solutions resulted in a significant improvement in gel elasticity under physiological conditions. The introduction of TSP to PM not only enhanced the viscosity of the gel, but also stimulated the gelation procedure. Due to the inclusion of TSP, the gel dissolution rate of the PM-based formulation was greatly reduced. The FTIR spectral analysis revealed the interaction between –OH groups of both polymers, resulting in a decline in the gelation temperature of the PM–TSP-based formulations. It was also detected in the cryo-SEM analysis that the pore size of the PM gel decreased and the depth of its pores increased with the inclusion of TSP. Furthermore, the in vitro release analysis indicated that the retention capacity of PM–TSP-based formulations was superior to that of the only PM-based formulation. The SEM study and the cell viability data demonstrated the biocompatibility and non-toxicity of TSP. Therefore, the designed formulation is fairly promising to be utilized as an in situ ophthalmic drug carrier. [ABSTRACT FROM AUTHOR]

Coal being the most abundant natural resource is used worldwide and shows graphite-like clusters. Here, for the first time, we report an innovative and cost-effective oxidative functionalization approach, followed by an acid-free and oxone oxidant-assisted solvothermal synthesis of graphene quantum dots from coal. This method involving the oxidative functionalization of coal was performed through the heat treatment of nitric acid, followed by an acid recovery process. Indeed, the solvothermal method used was entirely free from the utilization of strong acids, and involved a simple, eco-friendly, and salt-free purification process with a high production yield (∼45%). Due to the synergistic synthesis technique, our developed GQDs were found to exhibit a strong blue photoluminescence (PL) characteristic with a significantly high quantum yield (∼14.42%). High-resolution transmission electron microscopy (HRTEM) images indicated that the nanocrystalline GQDs had a uniform and narrow particle-size distribution in the range of 2.5–5 nm. The anticancer efficacy of the as-synthesized GQD nanomaterial was validated through cellular morphological pattern analysis and DAPI-staining images of neuroblastoma cells and breast cancer cells. In addition, the alteration of the mitochondrial membrane potential was scrutinized using JC-1 micrographs. Interestingly, the RITC-tagged GQDs showed cellular internalization within breast cancer cells. The robust functionality, luminescence stability, nanosecond lifetime, biocompatibility, and low toxicity of our developed GQDs suggest they could be promising probes for cancer therapeutic applications. This study unveils new opportunities for the sustainable production of GQDs with novel attributing features due to the easily availability of the raw materials, their cost-effective production, and fascinating photoluminescence property. [ABSTRACT FROM AUTHOR]

Nanoclay-based drug delivery vehicle has acquired immense recognition owing to its unique physico-chemical properties. In this study, tetracycline hydrochloride (TCH) drug was intercalated into the interlayer gallery of montmorillonite (Mt) clay by a cation exchange process. The intercalated nanocomposites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive X-ray and thermogravimetric study. It was evident from the characterization that TCH drug was successfully intercalated into the interlayer gallery of Mt clay. These clay-based formulations exhibited antibacterial activity against both Gram-positive and Gram-negative bacteria on analyses via zone inhibition methods. An in-vitro drug release study was performed in phosphate buffer at physiological temperature and interestingly it exhibited sustained and controlled release of TCH from the nanocomposites, after an initial burst-out effect. Overall, this study showed that these nanocomposite materials have immense potential for use in controlled drug delivery strategies for antibacterial treatment. [ABSTRACT FROM AUTHOR]

There has been extensive utilization of poloxamer 407 (PM) for the delivery of various ophthalmic drugs aimed at efficient ophthalmic drug delivery approach for longer precorneal residence time along with acceptable bioavailability of drugs. We have studied the effect of nanocellulose grafted collagen (CGC) on the performance of in situ gels based on PM for the controlled in vitro release of Ketorolac Tromethamine (KT). CGC has shown great influence evident by the reduction in PM critical gelation concentration, increased gel strength, and prolonged the release of loaded drugs compared with the virgin PM gel. The engineered nanocomposite formulations established an anomalous diffusion mechanism along with a Fickian diffusion controlled drug release for 1.5 & 1.75 w/v% CGC reinforced PM. Hence, the synthesized in situ nanocomposites are potential candidates for ophthalmic drug delivery system. Unlabelled Image • Cellulose nanocrystals grafted nano-collagen were prepared. • Enhanced poloxamer hydrogel strength using cellulose nanocrystals-g-nano-collagen • Sustained drug release of poloxamer modified nanocrystals-g-nano-collagen. • Thermoresponsive nanocomposite gels were prepared. [ABSTRACT FROM AUTHOR]

Resorcinol based reduction and capping of ultra-small colloidal silver nanoparticles (Ag NPs) optimally formed hydrogen bond driven clusters within the water-based solution. Large-area self-assembled fractal structures of Ag NPs aggregates were fabricated by solvent evaporation technique on silicon substrate. The final dried surface structures were found to be pH dependent which was adjusted to particular values after the optimal reduction of silver salt, capping of Ag NPs, followed by cluster formation at an optimum pH in the solution phase. These self-assembled surface structures show controlled enhancement of various surface optical phenomena such as Raman spectra of a model dye and luminescence of Ag NPs as a function of pH dependent fractal dimension of the resulting structures. The structure, morphology and various relevant optical properties of self-assembled fractals of Ag NPs were further established by combined use of X-Ray diffractometry (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), UV-Visible, photoluminescence and Raman spectroscopy analysis. Image 1 • Ag NPs were synthesized using resorcinol as reducing and capping agent and was found to be luminescent. • SPR show peaks at 353 and ~500 nm and their PL emission was observed at 411 nm and 544 nm respectively. • Fractal dimension (F D) was calculated to be 1.89 which decreases to ~1.6 with pH variation in acidic and basic. • R6G was used as probe molecules for SERS measurements which verified that the substrate has high sensitivity to SERS response. [ABSTRACT FROM AUTHOR]

Evaluation of the potential for oral sustained drug delivery of formulations with in - situ gelling properties is the main objective of the present investigation. Oral administration of aqueous dispersion of sodium alginate (1.5% w/v) containing calcium ions in complex form resulted in the formation of gel matrix as a consequence of the release of the calcium ions in the acidic environment of stomach fluid. Addition of methylcellulose, sodium chloride and polyethylene glycol improved the drug retention efficacy of the gel. In this investigation, the study on the influence of added excipients on the rheological and drug release properties of the formulations has been focused. In - vitro studies demonstrated diffusion-controlled release of paracetamol from the gels. The bioavailability of orally administered paracetamol from the in - situ gel F4 (composed of 1.5% sodium alginate, 1.5% methyl cellulose, 3% CaCO 3 , 2% NaCl 0.05% polyethylene glycol) administered in the stomach of rabbit, was more sustained as compared to the commercially available suspension Calpol® containing an identical dose of paracetamol. [ABSTRACT FROM AUTHOR]

[Display omitted] • Highly fluorescent carbon quantum dot with average size ∼ 3–6 nm have been synthesized successfully by simple methode. • The high fluorescence quenching ability towards heavy metal ions of Fe3+ was observed. • The average lifetime of (5.89648 ± 0.40) ns was calculated from TRPL decay curve. • Deep study on analysis of mechanism behind Fe3+ sensing. • The synthesized N-CQDs shows 80% photostability after 4 h continuous UV (365 nm) illumination. Carbon quantum dots (CQDs) based sensor has been built many times. Optical properties, such as optical absorption, have been neglected for too long. Here, we have reported the luminescence of blue-emitting nitrogen-doped carbon quantum dots (N-CQDs) with average particle size 3–6 nm, synthesized via a simple hydrothermal method, which give intense blue emission under 340 nm excitation wavelengths. As the fluorescence of N-CQDs can be efficiently quenched by Fe3+, the N-CQDs can be constructed as a sensor system for Fe3+ with good sensitivity and selectivity. Effective detection and quantification of Fe3+ at as little as 0.07 µM and 0.22 µM is achieved. [ABSTRACT FROM AUTHOR]

Abstract A green, efficient synthesis of cadmium oxide decorated reduced graphene oxide nanocomposites (RGO/CdO) was prepared by one-step co-precipitation and hydrothermal method. Crystalline nature of the nanocomposites was characterized by X-ray diffraction analysis. To evaluate the structural morphology and particle size, high resolution transmission electron microscopy were used. X-ray photoelectron spectroscopy, Raman spectroscopy and Fourier transform infrared spectroscopy techniques were employed to establish chemical structure of the nanocomposites and Atomic Force Microscopy was done to measure the thickness. The optical properties were evaluated by UV–visible absorption spectroscopy. Thermo-gravimetric analysis, BET surface area and zeta potential measurements were carried out to study the thermal and surface characteristics. The CdO nano-particles (NPs) decorated on RGO sheets exhibit better electrical conductivity compared to RGO. The antibacterial activity of the nanocomposites has also been monitored in different culture media imparting good potentiality than RGO. Graphical abstract Unlabelled Image Highlights • RGO/CdO nanocomposite was successfully synthesized by adopting green route. • Dextrose acts as reducing and stabilizing agent which is nontoxic, low cost and easily available. • The electrical conductivity of the nanocomposite is higher than RGO. • The antibacterial property of the nanocomposite imparting good potentiality compared to RGO [ABSTRACT FROM AUTHOR]

Ethoxy functionalized devulcanize natural rubber (DeVulcNR) is used as compatibilizer for silica/graphene oxide (SiO2@GO) hybrid fillers in the styrene butadiene rubber (SBR) to fabricate SBR composites. The dispersion behavior of SiO2@GO hybrid filler was investigated through scanning electron microscopy (SEM) analysis of the tensile fracture surface along with the broken rubber surface developed by plunging into liquid nitrogen. The rubber–filler interfacial interactions were evaluated through the measurement of equilibrium swelling experiment, fraction of immobilized polymer chain by DSC study, FTIR analysis, and molecular dynamics simulation. The results reveal that in the presence of DeVulcNR, the rubber–filler interaction is enhanced compared with that of the control formulations containing only SBR. SiO2@GO hybrid‐filler shows synergistic effect on the mechanical properties of the composites in the presence of DeVulcNR. The improved mechanical properties of the SiO2@GO hybrid filler rubber composites may be due to chemical interaction among the functional groups of SiO2 and GO with the DeVulcNR. Further, XRD study indicates that there is no significant layer‐by‐layer restack of GO in the SBR/DeVulcNR composites. The higher storage modulus and lower tan δ of the SiO2@GO hybrid filler rubber composites show superior interfacial interaction between rubber and filler compared with that of the control formulations. POLYM. COMPOS., 40:E1559–E1572, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Abstract Triblock poloxamer copolymer (PM) has been extensively utilized to deliver various ophthalmic pharmaceutical compounds. The aim of efficient ophthalmic drug delivery strategy is to attain the longer precorneal resident time and good bioavailability of drugs. In this pursuit, the influence of cellulose nanocrystals (CNC) on the in situ gelation behavior of PM and in vitro release of pilocarpine hydrochloride from the nanocomposites formulations was studied. The critical concentration of gelation of PM being 18% (wt/v) was dropped to 16.6% (wt/v) by the addition of a very low percentage of CNC. The reinforcing nature of CNC via H-bonding in the in situ nanocomposite gel also led to an increase in gel strength along with the sustained release of loaded drugs when compared with the pure PM gel. All formulations revealed that the drug release mechanism is controlled by the Fickian diffusion. Thus, the CNC has a significant effect on the gelation behavior, gel strength, and drug release kinetics of PM-CNC formulations. Graphical abstract Unlabelled Image Highlights • Reduced critical concentration of thermo-responsive gelation of poloxamer gel. • Cellulose nanocrystals influenced the in situ gelation behavior of poloxamer gel. • Increased poloxamer gel strength via H-bonds in the in situ nanocomposite gel. • Sustained release of loaded drugs from the nanocomposite gel. • Non-cytotoxic ODDS with reduced dissolution properties. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Ag@Ag 2 S core shell nanoparticles were synthesized by soft chemical route. • SPR of Ag NPs blue shifts from 408 to 378 nm with increasing sulfur ion concentration. • Ag@Ag 2 S CSNPs exhibit tunable (1.43–1.50 eV) NIR luminescence with increasing sulfur ion concentration. Abstract Ag-Ag 2 S core-shell nano-structured particles, prepared by soft chemical route, were found to be luminescent in the near-infrared (NIR) range. The silver nanoparticles were pre-synthesized with size control by poly-vinyl-pyrrolidone (PVP) polymer capping from silver nitrate solution, by reduction using sodium borohydride in solution, which were further subjected to reaction with sulfur ions in the later stage by mixing controlled amount of Na 2 S in the solution. With increasing concentration of sulfur ions, the plasmonic peak of Ag showed progressive blue shift and damping, leading to final diminishment. Enhanced NIR luminescence obtained from Ag@Ag 2 S core-shell nanoparticles were found to be asymmetric and blue shifting with reduced intensity and increasing sulfur ion concentration. The mechanism behind such a behavior is predicted due to formation of composite layer of Ag 2 S-Ag both at the surface and the volume, with Ag core at the center, diminishing in size with increasing sulfur concentration. The structure, chemical composition, morphology and final core-shell structure formation were further established by combination of X-ray diffractometry (XRD), X-ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM) analysis. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Sodium cholate surfactant assisted synthesis of polypyrrole (PPY) for CO 2 gas adsorption and dopamine detection. • Surfactant concentration above CMC produced rod shaped morphology of PPY. • PPY nanorod having highest surface area showed good electrochemical performance. • Highest CO 2 adsorption showed by PPY synthesized without any surfactant. • PPY nanorod modified GCE exhibited good electro-catalytic activity towards dopamine sensing. Abstract Nanostructured conducting polymers are known to function as electroactive materials in sensor devices for adsorption and detection of different analytes. For the purpose of dopamine (DA) detection and CO 2 gas adsorption we have prepared nanostructured polypyrrole (PPY) with the help of sodium cholate as surfactant. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) analyses and Brunauer–Emmett–Teller (BET) measurement have been done for the characterization of nanostructure and morphology of the prepared PPY. From the sorption measurement, it is observed that the rodlike PPY structures show highest N 2 uptake (91.6 mL g−1) along with appreciable surface area (85.81 m2/g) and porosity (2.53 and 4.51 nm) values. It is also observed that the maximum uptake of CO 2 is 173.885 mL g−1 at 195K for the PPY synthesized without any surfactant. Electrochemical characterization of PPY modified glassy carbon electrode (GCE) was done with impedance and cyclic voltammetry experiments. DA sensing in presence of ascorbic acid, uric acid and glucose was done by LSV technique. The PPY modified electrode exhibits sensitivity values of 0.301 and 0.19 μA μM−1 cm2 over two ranges of detection limits of 0.09–0.56 and 10–50 μM for dopamine, respectively (signal/noise = 3). [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis of bimetallic Au-Pd and monometallic Au and Pd nanoparticles (NPs) by successive reduction of the respective metal ions using phytochemicals in the form of plant extract under ambient conditions. Phytochemicals act both as reducing and shape directing agent for metal and alloy NPs. The synthesized nanostructures were characterized by different microscopic, spectroscopic and diffractometric techniques. Microscopic results confirmed that the shape and size of the alloy nanostructures can be tuned by varying the concentration ratio of metal ions in the reaction medium. Energy dispersive X-ray and X-ray photoelectron spectroscopic analysis confirmed the formation of bimetallic Au-Pd nanostructures. The purity and crystalline properties were studied by X-ray diffraction technique. UV–vis spectra were recorded to study the optical properties of the synthesized nanostructures. Further, we tested the catalytic activity of both the monometallic and bimetallic alloy nanostructures in borohydride reduction of hazardous organic dye molecules in aqueous medium. The bimetallic alloy NPs exhibit better catalytic activities compared to their respective monometallic nanoparticles. [ABSTRACT FROM AUTHOR]

In this work, we report the development of a cross-linked bio-composite consisting of graphene oxide, potato starch, cross-linker glutaraldehyde and its application to adsorption of the industrial dye, methylene blue, from aqueous solution. The inexpensiveness, non-hazardous nature and easy bio-degradability are the major reasons for the selection of starch material as one of the components of the bio-composite. The bio-composite has been characterized by FTIR, SEM, XRD, particle size and zeta potential analysis. The FTIR analysis reveals the nature of the binding sites and surface morphology of the bio-composite can be understood through SEM. The auto-phase separability of the adsorbent i.e., the precipitation of the adsorbent without any mechanical means is another factor which makes this particular material very attractive as an adsorbent. Parameters like adsorbent dosage, pH, temperature, rotation speed and salt concentration have been varied to find out the suitable dye adsorption conditions. Furthermore, the time dependence of adsorption process has been analyzed using pseudo-first and pseudo-second order kinetics. The adsorption isotherms have been constructed to suggest convincing mechanistic pathway for this adsorption process. Finally, desorption studies have been successfully performed in 3 cycles, establishing the reusability of the material, which should allow the adsorbent to be economically promising for practical application in wastewater treatment. [ABSTRACT FROM AUTHOR]

In this work, MoS 2 quantum dots (MSQDs) of average size ∼3.0 ± 1.2 nm in aqueous medium were synthesized by simple technique. Three different emissive sites of MSQDs were observed from the time-resolved photoluminescence decay curves with an average lifetime of 3.75 ± 0.40 ns. The high fluorescence quenching ability toward heavy metal ions of synthesized MSQDs was used for Fe3+ ion sensing, and sensitivity was 7.9 × 10−4 μM−1. The limits of detection and quantification were ∼0.24 and ∼0.71 μM, respectively. The zeta potential (ζ) of bare MSQD was −28.0 mV and was more positive in the presence of Fe3+ compared to other metal ions. It is observed that the value of ζ became more positive with increasing Fe3+ ion concentrations. Hence, tri-mode sensing techniques were used for sensing different metal ions and showed excellent selectivity toward Fe3+ ions. [Display omitted] • Aqueous fluorescent MSQDs solution of average size ∼3.0 ± 1.2 nm was synthesized. • The average lifetime of (3.75 ± 0.40) ns was calculated from TRPL decay curve. • The high fluorescence quenching ability towards heavy metal ions of Fe3+ was observed. • The sensitivity and LOD are found to be 7.9 × 10−4 μM−1 and 0.24 μM, respectively. • The Zeta potential of bare MSQD is found to be −28.0 mV. [ABSTRACT FROM AUTHOR]

Non-toxic nanocomposites based bio-films obtained from methylcellulose (MC) can reduce environmental problems associated with synthetic polymers. A new facile route for the isolation of cellulose nano-crystals (CNC) from jute waste is successfully utilized here. The fabrication of CNC reinforced MC nanocomposites by film casting technique and the studies of the effect of CNC on the properties of the MC based nanocomposites have been reported. The synthesized nanocomposites have shown improved UV resistance, mechanical, barrier, and thermal properties. FTIR results established the physicochemical compatibility between the drug, MC and CNC in nanocomposites. In vitro permeation studies performed by using Franz diffusion cell revealed diffusion mediated sustained drug release from the devices due to the presence of interaction between MC and CNC through H-bonding, electrostatic interaction between the hydrophilic polymer/CNC chains with the drug and the formation of tortuous path. The nanocomposites can be used for edible packaging and transdermal drug delivery. [ABSTRACT FROM AUTHOR]

Active packaging is one of the interesting concepts in food industry which extend the shelf-life of the food products. The purpose of this work was to develop nontoxic antimicrobial nanocomposite films. Benzyltrimethylammonium chloride modified montmorillonite (BMMT) were used as nano-filler and the prepared BMMT was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis. Polyethylene glycol (PEG) plasticized cellulose acetate butyrate (CAB) films with different ratios of PEG and CAB was prepared and it was found that the 20 wt% PEG in CAB matrix (CBP 20 ) gave optimal results in terms of mechanical properties. BMMT was mixed with CBP 20 in different proportions to prepare nanocomposites. 3 wt% BMMT loaded nanocomposite gave best in terms of the barrier and mechanical properties. The storage modulus, thermal stability, glass transition, and melting temperature of the nanocomposites increased with the loading of 1, 3, and 5 wt% of BMMT. Furthermore, these nanocomposites showed nontoxic and antimicrobial behavior. [ABSTRACT FROM AUTHOR]

There is a need for reuse of waste cotton lint (WCL) from the blow room of yarn spinning mills. The drive to use this material for the synthesis of nanocellulose is difficult because of the several purification/pretreatment processes. Here, we developed a combined single bath purification process of WCL and utilized it for the synthesis of nano-crystalline cellulose crystals (NCs) which are valuable nanomaterials with novel properties along with acid recovery for reuse. The micrograph of the synthesized NCs confirmed a network of nano-sized crystalline cellulose crystals having nano ranged diameter of NCs isolated by two processes. The FTIR result established the removal of impurities and hemicelluloses from WCL. The crystallinity index of WCL (∼89.97%) is improved to ∼96% and ∼94% for sulphuric acid and nitric acid synthesized NCs (NC1 and NC2). The crystallite size of WCL, CTWCL, NC1, and NC2 was calculated using XRD and found to be 101.56, 103.54, 98.81, and 95.6 nm respectively. The hydrodynamic size (Z-average) (d nm), polydispersity index and zeta potential of NCs was also studied using dynamic light scattering (DLS). The thermal stability of the NC1 is better than that of NC2. These NCs can be used as reinforcing filler/barrier material. [ABSTRACT FROM AUTHOR]

Nowadays, bio-derived cellulose nano-fibrils based nanocomposites is gaining utmost interest in the area of barrier films for food packaging, as reinforcing filler to make biodegradable nanocomposites with different biopolymers for various applications such as transdermal drug delivery, edible packaging and tissue scaffolding. Ultrasound-assisted preparation of hydroxypropylmethylcellulose based nanocomposites with cellulose nano-fibrils were carried out following solution mixing technique. The crystalline nature of cellulose nano-fibrils has been scrutinized by X-ray diffraction study. The field emission-scanning electron micrographs of cellulose nano-fibrils revealed a network of nano-fibrillar morphology. The Fourier transform infrared spectroscopy results of cellulose nano-fibrils confirmed the removal of lignin and hemicellulose from raw jute ( Corchorus olitorius L.) fibres. The storage modulus and tensile properties of hydroxypropyl methylcellulose films increased up to the addition of 1.00 wt% cellulose nano-fibrils. The moisture affinity of hydrophilic hydroxypropylmethylcellulose has also been reduced at 1.00 wt% cellulose nano-fibrils loading. The impact of cellulose nano-fibrils loading on the cumulative percentage of drug release from prepared nanocomposites films has been explored accordingly. By utilizing these versatilities of cellulose nano-fibrils, the fabricated nanocomposites are expected to be highly promising in the area of packaging and transdermal drug delivery system. [ABSTRACT FROM AUTHOR]

The delivery of diltiazem hydrochloride in therapeutical doses has attracted an immense research interest. However, its slower penetration through the transdermal route has stipulated to develop a competent transdermal membrane. Therefore, a nanocomposite based patch was formulated by exploring co-polymer and jute derived nano-cellulose. Poly( N -isopropylacrylamide) was grafted into guar gum (GG- g -PNIPAAm) with different feeding ratios. The co-polymer formation was authenticated by FTIR and 13C NMR spectra. The nanocomposite were prepared by incorporating nanofibre (0.5–2 wt%) into GG- g -PNIPAAm. The structural and morphological studies supported good interactions and presence of nano-cellulose on co-polymer. GG- g -PNIPAAm has showed higher thermostability than guar gum. Moreover, the addition of CNF has improved the thermo-mechanical and barrier properties of the nanocomposite. The nanocomposite containing 1 wt% CNF was found to be best performing. The patch showed in-vitro cyto-compatibility and non-irritant behaviour. The in-vitro release study of best nanocomposite revealed controlled drug release capability with 7.78 and 22.9% after 5 and 20 h, respectively. [ABSTRACT FROM AUTHOR]

Cellulose nanofibrils (CNFs) have attracted attention as a promising material in the biomedical field because of their outstanding properties such as hydrophilicity, biocompatibility, biodegradability, and high surface area. In this work, we have prepared cellulose nanofibrils from jute fibres (JF), to develop a CNF/chitosan transdermal film for the delivery of ketorolec tromethamine (KT) where the CNFs act as an elegant nanometric carrier. The KT-loaded CNF/chitosan transdermal film matrices have been characterized by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Fourier transform infrared spectroscopy (FTIR) reveals the successful KT loading into the CNF/chitosan transdermal film. Scanning electron microscopy (SEM) study shows the different morphological features of the CNF/chitosan transdermal films. The crystalline nature of the CNF/chitosan transdermal films has been analyzed by X-ray diffraction study. Release profiles from the CNF/chitosan matrices indicate that the drug release rate is sustained with the incorporation of CNFs. We believe that this new nanocarrier may be a potential choice for transdermal drug delivery systems. [ABSTRACT FROM AUTHOR]

Recently transdermal drug delivery systems (TDDS) based on polymeric nanocomposites have been widely researched by polymer and biomedical scientists for the remedy of various diseases. Thus to develop an efficient patch, we have synthesized guar gum-g-polyacrylamide by free radical polymerization using potassium persulphate as an initiator. The transdermal membranes were fabricated via solution casting, by incorporating different wt% of nanosilica and diltiazem hydrochloride to the synthesized copolymer. The resulting copolymer and the nanocomposite membranes were characterized using solid state 13C nuclear magnetic resonance, Fourier transform infrared spectra, thermo-gravimetric analysis, electron microscopy and viscometry. A hydro-swelling study and surface contact angle measurement showed that the membrane containing 1 wt% nanosilica was the most hydrophobic. The in vitro drug release patterns of all the transdermal membranes showed that the nanocomposite containing 1 wt% nanosilica provides the best result with 8.58 and 24.76% drug release after 5 and 20 h, respectively. Furthermore, the nanocomposite formulation exhibited good cyto-compatibility and non-irritant behaviour, which are primary requirements for an efficient transdermal drug delivery system. [ABSTRACT FROM AUTHOR]

The effect of gellan gum on the gelation behavior and in-vitro release of a specific drug named pilocarpine hydrochloride from different ophthalmic formulations based on poloxamer 407 is examined. The mixture of 0.3 wt% gellan gum and 18 wt% poloxamer (PM) solutions show a considerable increase in gel strength in physiological condition. Gel dissolution rate from PM based formulation is significantly decreased due to the addition of gellan gum. FTIR spectra analysis witnesses an interaction in between OH groups of two polymers which accounts for lowering in gelation temperature of PM-gellan gum based formulations. It is also observed from the cryo-SEM study that the pore size of PM gel decreases with an addition of gellan gum and in-vitro release studies indicate that PM-gellan gum based formulation retain drug better than the PM solution alone. Therefore, the developed formulation has the potential to be utilized as an in-situ ophthalmic drug carrier. [ABSTRACT FROM AUTHOR]

This study sought to detect the presence of sucrose as an adulterant in selected honey varieties from different floral origins by employing Electrical Impedance Spectroscopy (EIS) technique which has been simultaneously supported by Fourier Transform-Mid Infrared Spectroscopy (FT-MIR) measurements to provide a rapid, robust yet simple platform for honey quality evaluation. Variation of electrical parameters such as impedance, capacitance and conductance for 10%, 20%, 30%, 40%, 50%, 60% and 70% (w/w) sucrose syrup (SS) adulterated honey samples are analyzed and their respective current-voltage (I-V) characteristics are studied. Capacitance, conductance and net current flowing through the system are observed to decrease linearly whereas system impedance has been found to increase similarly with the increase in adulterant content. Also, FT-MIR measurements in the spectral region between 1800 cm −1 and 650 cm −1 reveal the increment of absorbance values due to the addition of SS. Full-Width-at-Half-Maximum (FWHM) is estimated from the spectral peak 1056 cm −1 for all pure and adulterated honey samples and is observed to be linearly increasing with increase in adulterant content. Finally, the coefficient of sensitivity has been extracted for all varieties of honey considered in terms of the measured conductance values. [ABSTRACT FROM AUTHOR]

Proflavine, a nitrogen-containing dye is used for DNA staining and as an efficient marker, however, it is harmful to body cells, and its efficient removal is essential. In this work, graphene oxide (GO) has been used as an adsorbent for the removal of the dye through the process of adsorption. Though GO is now being used as an adsorbent for the removal of industrial dyes, very few experiments have been done on biologically useful dyes. GO is synthesized from graphite powder by the modified Hummer's method and is characterized by X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), Raman and ultra-violet spectroscopies, etc. These characterization techniques indicate the presence of oxygen containing functional groups, e.g., carbonyl, carboxyl and hydroxyl groups on the graphene sheets. These sheets are held well apart by these groups. Parameters like concentration of the adsorbent, pH and temperature have been varied to find the optimum conditions for the most efficient removal of the dye molecules from the solution. Then, for the optimum external conditions, the time dependence of the adsorption was analyzed using pseudo-first and pseudo-second orders kinetics. The adsorption isotherms were also obtaining throws light on the mechanism of the adsorption process which we investigated further by using FTIR characterization. [ABSTRACT FROM AUTHOR]

Chemical reduction of graphene oxide (GO) to graphene employs the use of toxic and environmentally harmful reducing agents, hindering mass production of graphene which is of tremendous technological importance. In this study we report a green approach to the synthesis of graphene, bio-reduced by crude polysaccharide. The polysaccharide reduces exfoliated GO to graphene at room temperature in an aqueous medium. Transmission electron microscopy image provides clear evidence for the formation of few layer graphene. Characterization of the resulting polysaccharide reduced GO by Raman spectroscopy, Fourier transform infrared spectroscopy and Energy dispersive X-ray analysis confirms reduction of GO to graphene. We also investigated the degree of biosafety of the reduced GO and found it to be safe under 100 μg/ml. [ABSTRACT FROM AUTHOR]

An analytical model is developed to describe the dielectric behaviour of pure DI water-sucrose solution in which sodium carbonate (Na 2 CO 3 ) is added as an adulterant. Relative impact of constituent dipoles has been emphasized and multi-body dipolar interactions have been explicitly considered for a comprehensive analysis of such a system in thermal equilibrium. The theoretical model is verified with experimental data obtained from the impedance and capacitance based spectroscopic measurements. The impedance and capacitance of DI water-sucrose solution are observed to vary in a quasi-oscillatory nature with different sucrose content in it. However, such variation shows a decreasing trend and linear nature for a minimum of 1% adulterant content. The system impedance decreases and capacitance increases with increasing adulterant wt% for a given sucrose concentration. For the 0% of adulterant in the solution with varying sucrose content, the impedance and capacitance have varied from 140.12 kΩ to 236.17 kΩ and 40.7 pF to 44.2 pF, respectively. However, such values change from 111 Ω to 157 kΩ and 42.5 pF to 72 μF for the adulterant content up to 5%. [ABSTRACT FROM AUTHOR]

Lac, a natural resin, is used to synthesize gold nanoparticles (AuNPs). This biodegradable natural fluorophore contains different laccaic acids, which consist of mainly the derivatives of red anthraquinone dye. For the first time, we report an in situ green synthesis of fluorophore stabilized AuNPs. The synthesis of AuNPs is monitored using both excitation and emission spectrophotometry, which gives us an idea about the progress of the reaction during nanoparticles synthesis. The size of the synthesized nanoparticles is visualised by TEM. The TEM data of the AuNPs are also correlated using DLS measurements, and the zeta potential values establish the stability of the nanoparticles. The FTIR spectra indicate the different groups present in lac and also their probable interactions during the reducing-cum-stabilizing process with the nanoparticles. The AuNPs are crystalline in nature, which is established by XRD analysis. The lac extract also binds with calf thymus DNA and forms a ground state complex, which is established spectrophotometrically by UV-Vis, as well as fluorimetrically. The antimicrobial tests against bacteria and the antitoxicity study have revealed that the lac stabilized AuNPs are safe and non-toxic, having the potential for clinical applications in the medical field. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis of polyaniline nanoribbons doped with a natural dye extracted from lac insect (LAC-PANI). • Demonstration of its highly specific fluorescence sensing properties against aqueous AsO 4 3− and Fe3+ ions. • Sharp increase and quenching of fluorescence intensity upon exposure to Fe3+ and AsO 4 3−, respectively. • Demonstration as a NOT-AND compound molecular logic gate for simultaneous detection of Fe3+ and AsO 4 3−. Detection of contaminants dissolved in water is an essential step for water quality monitoring and can guide us from consuming unhealthy water. Herein, we demonstrate the development of a novel low-cost polymer by doping polyaniline nanoribbons with lac-extract (LAC-PANI) and report its excellent fluorescence sensing properties against aqueous AsO 4 3− and Fe3+ ions, both of which AsO 4 3− and Fe3+can pose health hazard for humans with the former being extremely toxic. When excited with radiation of 320 nm, the sensor showed contrasting fluorescence response against AsO 4 3− and Fe3+ ions as the luminescence intensity showed sharp quenching upon exposure to Fe3+ but against AsO 4 3− it showed a sharp rise in intensity. When other cations and oxoanions were concurrently tested with Fe3+ and AsO 4 3− respectively, the sensor showed high specificity only to these two ions. Furthermore, a reversible and distinct fluorescence turn on–off-on switching response was observed upon sequential addition of AsO 4 3−, Fe3+ and AsO 4 3− ions which points to the utility of the sensor as a NOT-AND compound molecular logic gate for simultaneous detection of two electronically divergent analyte classes. Thus, the LAC-PANI sensor developed in this work shows enormous potential for next generation fluorescence sensor useful for water quality monitoring. [ABSTRACT FROM AUTHOR]