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The present study covers the fabrication of flexible piezoelectric nanogenerators and their application towards sustainable power generation. The rod-like structure of erbium-doped ZnO (EZ) nanoparticles prepared by the hydrothermal synthesis route was successfully incorporated inside the polyvinylidene fluoride (PVDF) matrix using the solution casting method. Solution casting is an easy and cost-effective method for fabricating laminated, thin, flexible and lightweight EZ-PVDF nanocomposite films. The formation of the desired crystallographic phase of EZ-PVDF nanocomposite films and the presence of rod-like EZ nanoparticles inside the PVDF matrix were confirmed using X-ray diffraction and FESEM. The enhancement of the ß-phase fraction of the EZ-PVDF nanocomposite films as compared to bare PVDF was estimated using FTIR spectroscopy. The presence of a ferroelectric phase in the EZ-PVDF nanocomposite films was found due to the formation of a large area of interfaces between the EZ nanoparticles and the PVDF matrix. The maximum polarizations of 0.00696 µC cm-2 and 0.00683 µC cm-2 for two samples (EZP1 and EZP2, respectively) were observed at an electric field of 1.25 kV cm-1. The piezoelectric voltages were observed at relatively low frequencies for both nanocomposite films. The maximum piezoelectric voltages of 18.9 V and 15.5 V were observed at a 1 Hz frequency for EZP1 and EZP2, respectively. The output piezoelectric current of 16.88 mA and the maximum power density of 7773.68 W m-3 for EZP1 ensure its potential as an efficient piezoelectric nanogenerator with greater efficiency than those reported previously in published articles. The change in the piezoelectric voltage response of the nanocomposite films as a function of mechanical movement of human external body parts renders them the most suitable candidate for human-machine interfacing (HMI) applications, such as bending sensors and human motion sensors.
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Amid rising water contamination from industrial sources, tackling toxic dyes and pathogens is critical. Photocatalysis offers a cost-effective and eco-friendly solution to this pressing challenges. Herein, we synthesized Te4+ and Er3+ doped ZrO2 photocatalysts through hydrothermal method and investigated their efficacy in degrading Congo red (CR) and pathogens under visible light. XRD and Raman Spectroscopy confirm monoclinic and tetragonal mixed-phases without any impurities. Doping-induced defects, reduced crystalline diameter, high surface area, modified bandgap (2.95 eV), photoluminescence quenching, coupled with interfacial polarization, contribute to EZO's excellent dielectric response (1.149 × 106), for achieving remarkable photocatalytic activity, verified by photoelectrochemical measurements, LC-MS and phytotoxicity analysis. Under optimal conditions, EZO achieves 99% CR degradation within 100 min (TOC 79.9%), surpassing ZO (77%) and TZO (84%). Catalyst dosages, dye concentrations, and solution pH effect on EZO's photocatalytic performance are systematically assessed. Scavenging experiment emphasized the pivotal role of · OH in CR degradation with 96.4% efficiency after 4 cycles, affirming its remarkable stability. Moreover, EZO demonstrates ROS-mediated antibacterial activity against E. faecalis and E. coli bacteria under visible light, achieving >97% and >94% inhibition rate with an inhibition zone > 3 mm. Hence, the nanoparticle's dual action offers a practical solution for treating contaminated wastewater, ensuring safe irrigation.
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Antibacterianos , Circonio , Antibacterianos/química , Antibacterianos/farmacología , Catálisis , Circonio/química , Nanopartículas/química , Erbio/química , Rojo Congo/químicaRESUMEN
In the modern era, water pollution, especially from industries, agricultural farms, and residential areas, is caused by the release of a large scale of heavy metals, organic pollutants, chemicals, etc., into the environment, posing a serious threat to aquatic ecosystems and nature. Moreover, untreated sewage waste discharged directly into nearby water bodies can cause various diseases to mankind due to the high load of fecal coliform bacteria. This work demonstrates the development of a biocompatible, cost-effective, highly robust, efficient, flexible, freestanding, and reusable membrane using naturally formed biocompatible kaolinite clay-doped poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) for effective piezodynamic destruction of coliform bacteria. In this study, Escherichia coli (E. coli) and Enterococcus faecalis (E. faecalis) have been used to evaluate the mechanical stimulus-responsive antibacterial efficacy of the nanocomposite membrane. The membrane can effectively eradicate nearly 99% viable E. coli and 97% E. faecalis within a span of 40 min under mechanical stimulation (soft ultrasound â¼15 kHz). To further understand the mechanism, an evaluation of reactive oxygen species and bacterial FESEM was performed. These studies revealed that bacterial cells suffered severe visible cell damage after 40 min of piezocatalysis, elucidating the fact that the synthesized membrane is capable of producing a superior piezodynamic antibacterial effect.
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Escherichia coli , Aguas Residuales , Arcilla , Ecosistema , Antibacterianos/farmacología , BacteriasRESUMEN
The drawbacks inherent to traditional antibacterial therapies, coupled with the escalating prevalence of multi-drug resistant (MDR) microorganisms, have prompted the imperative need for novel antibacterial strategies. Accordingly, the emerging field of piezocatalysis in semiconductors harnesses mechanical stress to drive chemical reactions by utilizing piezo-generated free charge carriers, presenting a promising technology. To the best of our knowledge, this study is the first to provide a comprehensive overview of the eradication of pathogenic S. aureus bacteria using few-layer black phosphorus (SCBP) piezo catalyst under mechanical stimuli, along with the exploration of temperature dependent dielectric properties. The synthesis of the piezo catalysts involved a one-step cost-effective sonochemical method, and its structural, morphological, elemental, optical, and overall polarization properties were thoroughly characterized and compared with the traditional method-derived product (TABP). The synthesis-introduced defects, reduced crystalline diameters, modified bandgap (1.76 eV), nanoparticle aggregation, photoluminescence quenching, along with interfacial polarization, synergistically contribute to SCBP's exceptional dielectric response (4.596 × 107 @40 Hz), which in turn enhanced the piezocatalytic activity. When subjected to soft ultrasound stimulation at 15 kHz, the piezo catalyst SCBP demonstrated significant ROS-mediated antibacterial activity, resulting in a â¼94.7% mortality rate within 40 minutes. The impact of this study extends to cost-effective energy storage devices and advances in antibacterial therapy, opening new dimensions in both fields.
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Nanopartículas , Staphylococcus aureus , Antibacterianos/farmacología , Fósforo , SemiconductoresRESUMEN
Wound or injury is a breakdown in the skin's protective function as well as damage to the normal tissues. Wound healing is a dynamic and complex phenomenon of replacing injured skin or body tissues. In ancient times theCalendula officinalisandHibiscus rosa-sinensisflowers were extensively used by the tribal communities as herbal medicine for various complications including wound healing. But loading and delivery of such herbal medicines are challenging because it maintains their molecular structure against temperature, moisture, and other ambient factors. This study has fabricated xanthan gum (XG) hydrogel through a facile process and encapsulatedC. officinalisandH. rosa-sinensisflower extract. The resulting hydrogel was characterized by different physical methods like x-ray diffractometer, UV-vis spectroscopy, Fourier transform infrared spectroscopy, SEM, dynamic light scattering, electronkinetic potential in colloidal systems (ZETA) potential, thermogravimetric differential thermal analysis (TGA-DTA), etc. The polyherbal extract was phytochemically screened and observed that flavonoids, alkaloids, terpenoids, tannins, saponins, anthraquinones, glycosides, amino acids, and a few percentages of reducing sugar were present in the polyherbal extract. Polyherbal extract encapsulated XG hydrogel (X@C-H) significantly enhanced the proliferation of fibroblast and keratinocyte cell lines in comparison to the bare excipient treated cells as determined by 3-(4, 5-dimethylthiazol-2-Yl)-2, 5-diphenyltetrazolium bromide assay. Also, the proliferation of these cells was confirmed by BrdU assay and enhanced expression of pAkt. In anin-vivostudy, wound healing activity of BALB/c mice was carried out and we observed that X@C-H hydrogel showed significant result compared to the other groups (untreated, X, X@C, X@H). Henceforth, we conclude that this synthesized biocompatible hydrogel could emerge as a promising carrier of more than one herbal excipients.
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Hidrogeles , Plantas Medicinales , Animales , Ratones , Humanos , Masculino , Hidrogeles/química , Cicatrización de Heridas , Línea Celular , Flores , Extractos Vegetales/químicaRESUMEN
The limitations associated with conventional antibacterial therapies and the subsequent amplification of multidrug-resistant (MDR) microorganisms have increased, necessitating the urgent development of innovative antibacterial techniques. Accordingly, nanoparticle-mediated therapeutics have emerged as potential candidates for antibacterial treatment due to their suitable dimensions, penetration capacity, and high efficiency in targeted drug delivery. However, although nanoparticle-based drug delivery systems have been demonstrated to be effective, they are limited by their overuse and unwanted side effects. Thus, to overcome these drawbacks, stimulus-responsive antibiotic delivery has been extended as a promising strategy for site-specific restricted drug exemption. Nano-formulations that are triggered by various stimuli, such as intrinsic, extrinsic, and bacterial stimuli, have been developed. Thus, by harnessing the physicochemical properties of various nanoparticles, the selective release of therapeutic cargoes can be achieved through the application of a variety of local stimuli such as light, sound, irradiation, pH, and magnetic field. In this review, we also highlight the progress and perspectives of stimulus-responsive combination therapy, with special emphasis on the eradication of MDR strains and biofilms. Hence, this review addresses the advancement and challenges in the applications of stimulus-responsive nanoparticles together with the various future prospects of this technique.
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Sistemas de Liberación de Medicamentos , Nanopartículas , Sistemas de Liberación de Medicamentos/métodos , Antibacterianos/química , Nanopartículas/química , Campos Magnéticos , BacteriasRESUMEN
Herein, electroactive polymer based photo-induced hybrid power cell has been developed using CTAB/PVDF composite film in a sustainable manner. First high dielectric polymer film has been prepared by doping CTAB in PVDF matrix via solution casting method. In the basic configuration of this hybrid power cell, aqueous electrolyte solution of PVA-MnO2-Eosin Y has been utilized as solar light absorber and photo-electron generator whereas the high dielectric CTAB/PVDF (~ 400) is used as dielectric separator cum storage part in a very transparent way. The cell shows maximum voltage [Formula: see text] 1.1 V with short-circuit current density ~ 7.83 mA/cm2 under ~ 110 mW/cm2 normal light illumination. The device reveal almost same performance for a long time (30 days). The high storage impact of the hybrid cell is investigated by its promising conversion efficiency [Formula: see text] with energy density and power density [Formula: see text] mWh/m2 and [Formula: see text] 5.5 W/m2 respectively.
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This work reports a solvothermal synthesis of ferromagnetic bismuth ferrite (BFO) nanoparticle and its piezo activity in the domain of catalytic degradation of carcinogenic and genotoxic rhodamine B (RhB) dye and pathogenic Escherichia coli bacteria as well. After synthesis and characterization, the structural and morphological features of the catalyst were further investigated using density functional theory (DFT), which enabled us to estimate the polarizability and many other important electrical properties of the synthesized material. The DFT study reveals remarkably high polarizability and dipole moment, which were utilized to validate the generation of piezo response by the synthesized material. Interestingly, we found enhanced piezo catalytic degradation efficiency (η â¼ 99%) along with a high rate constant (k â¼ 2.259 × 10-2 min-1), indicating a fast and efficient degradation process. In the case of pathogenic bacteria E. coli, the degradation efficacy was found to be â¼94%. Moreover, the extraction of this catalyst is quite simple. Due to its high remanent magnetization (retentivity â¼0.08 emu g-1), the catalyst can be extracted from the treated water sample by using external magnetic stimulation, making it a potential candidate for sustainable wastewater treatment.
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Bismuto , Nanopartículas , Bismuto/química , Escherichia coli , Agua , Fenómenos MagnéticosRESUMEN
This article reports the fluorometric detection of toxic hexavalent chromium Cr (VI)) in wastewater and Cr (VI) contaminated living cells using in-situ grown carbon quantum dots into the goethite (α-FeOOH) nano-matrix. The synthesized nano-hybrid shows enormous potential in determining the chromium contamination levels in various types of water samples. This selective fluorometric probe is enormously sensitive (LOD 81 nM) toward hexavalent chromium, which makes it a dedicated chromium sensor. Moreover, the sensing mechanism has been assessed using Stern-Volmer's equation and fluorescence lifetime experiments showing the simultaneous occurrence of photoinduced electron transfer and the inner filter effect. This chromium sensor has also been employed to assess the contamination level in real-life industrial wastewater. The performance of this probe in a real-life wastewater sample is quite commendable. Further, this biocompatible fluorometric probe has been used to demonstrate the in-vitro sensing of Cr (VI) in HeLa cells. The rapid detection mechanism of hexavalent chromium in living cells has been validated using theoretical docking simulations. Henceforth, this fluorometric sensor material could open new avenues not only in wastewater monitoring but also in biomedical applications.
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Aguas Residuales , Contaminantes Químicos del Agua , Carbono , Cromo/análisis , Células HeLa , Humanos , Compuestos de Hierro , Minerales , Contaminantes Químicos del Agua/análisisRESUMEN
A family of dioxidovanadium(V) complexes (1-4) of the type [Na(H2O)x]+[VVO2(HL1-4)]- (x = 4, 4.5 and 7) where HL2- represents the dianionic form of 2-hydroxybenzoylhydrazone of 2-hydroxyacetophenone (H2L1, complex 1), 2-hydroxy-5-methylacetophenone (H2L2, complex 2), 2-hydroxy-5-methoxyacetophenone (H2L3, complex 3) and 2-hydroxy-5-chloroacetophenone (H2L4, complex 4), have been synthesized and characterized by analytical and spectral methods. These complexes exhibited the potential abilities to suppress the erythrocytes carbonic anhydrase enzymatic activity in type 1 and type 2 diabetic patients (in vitro), promising antidiabetic activity against T2 diabetic mice (in vivo). They also exhibited significant cytotoxic activity against cervical cancer (SiHa) cells (in vitro) as the IC50 value of complexes 1, 2 and 4 is substantially lower than the value found for cisplatin while that of 3 is comparable and follow the order: 4 < 1 < 2 < 3 and can kill the cells by apoptosis via the generation of reactive oxygen species (ROS). The complexes are soluble both in water and octanol media and also non-toxic at working concentrations. The antidiabetic activity of these four complexes follows the order: 4 > 2 > 1 > 3 while both the carbonic anhydrase and cytotoxic activity follow the order: 4 > 1 > 2 > 3 suggesting that complex 4, containing electron withdrawing Cl atom is the most reactive while 3 with electron donating OCH3 group is the least reactive species. The molecular docking study on hCA-I and hCA-II demonstrates that complexes interact via hydrogen bonding as well as different types of π-stacking.
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Antineoplásicos , Anhidrasas Carbónicas , Diabetes Mellitus Experimental , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Inhibidores de Anhidrasa Carbónica/química , Inhibidores de Anhidrasa Carbónica/farmacología , Anhidrasas Carbónicas/metabolismo , Diabetes Mellitus Experimental/tratamiento farmacológico , Humanos , Hidrazonas/química , Hidrazonas/farmacología , Hipoglucemiantes/farmacología , Ratones , Simulación del Acoplamiento Molecular , Relación Estructura-ActividadRESUMEN
This article reports a facile strategy to detect hexavalent chromium (Cr (VI)) using a naturally formed mineral (kyanite) based fluorometric sensor. Nitrogenous carbon dots have been incorporated into natural kyanite (KYCD) nanoparticles causing a stable bright blue fluorescence compared to its pristine counterpart. This sensing probe structurally stabilizes and resists the agglomeration of carbon dots, thus retaining fluorescence quality for a longer period. The promising bright blue fluorescence has been utilized further to detect Cr (VI) in wastewater and living cells. Ease of synthesis, low cost, and stability of the system offers the benefit for large-scale production, which is convenient for industrial production the sensing probe. The sensor shows high selectivity and sensitivity (LOD and LOQ of 0.11 µM and 0.36 µM respectively in case of linear fitting, whereas 0.26 µM and 0.88 µM respectively for full range plot) towards hexavalent chromium in presence of other interfering elements. A detailed study of photoinduced electron transfer (PET) mediated rapid 'turn off' sensing mechanism was carried out using Time-Dependent Density functional (TDDFT) calculations. The sensing efficacy of the probe remains unaltered under a wide range of pH and can be effective in various water types. Onsite sampling and probing of Cr (VI) in tannery wastewater has been performed to validate its real-life efficiency that yields excellent results. The sensor can effectively detect chromium at a cellular level (HeLa cells) in a similar way as the bright blue fluorescence diminishes in presence of the quenching ion. Experimental in vitro studies along with theoretical docking analysis has been conducted to substantiate such issues and a higher possibility of fluorophore binding was found for Isoleucine (2.9 Å), Serine (2.96 Å), and Glycine (3.16 Å). This biocompatible sensor rapidly senses hexavalent chromium in living cells, which makes this efficient probe a true heavy metal-induced carcinogen sensor.
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Nanopartículas , Contaminantes Químicos del Agua , Silicatos de Aluminio , Carbono , Cromo/análisis , Células HeLa , Humanos , Aguas Residuales/análisis , Contaminantes Químicos del Agua/análisisRESUMEN
Among several forms of water pollutants, common pesticides, herbicides, organic dyes and heavy metals present serious and persistent threats to human health due to their severe toxicity. Recently, piezocatalysis based removal of pollutants has become a promising field of research to combat such pollutions by virtue of the piezoelectric effect. In reality, piezoelectric materials can produce electron-hole separation upon external vibration, which greatly enhances the production of various reactive oxygen species (ROS) and further increases the pollutant degradation rate. Piezocatalysis does not alter the quality or composition of water, like several other conventional techniques (adsorption and photocatalysis), which makes this technique non-invasive. The simplicity and tremendously high efficacy of piezocatalysis have attracted researchers worldwide and thus various functional materials are employed for piezocatalytic wastewater remediation. In this frontier, we highlight and demonstrate recent developments on polymer based piezocatalytic nanocomposites to treat industrial wastewater in a facile manner that holds strong potential to be translated into a clean and green technology.
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Energy harvesting from natural resources has gained much attention due to the huge increase in the demand for portable electronic devices and the shortage of conventional energy resources in general. In the present work, the fabrication and realistic applications of a piezoelectric nanogenerator (PENG) using polydimethylsiloxane (PDMS) and the abundantly available, environment-friendly natural fiber Sonchus asper (SA) have been discussed. The biocompatible, low-cost SA fibers were flexible enough and showed high piezoelectric properties as active materials in the study. The SA pappus based piezoelectric nanogenerator demonstrated its ability to convert the harvested biomechanical energy into electrical energy from the various mechanical energy sources available in our environment. The SA pappus/PDMS thin film based piezoelectric nanogenerator (SPENG) fabricated in the laboratory showed colossal output performances (open circuit output voltage, V OC â¼81.2 V; short circuit current, I SC â¼1.0 µA) by continuous finger impartation. Uniform output performance was also obtained by the application of uniform force on the devices (e.g., â¼42 V for 5 N force at 10 Hz frequency). The SPENG was capable to charge a 2.2 µF capacitor to 3.2 V within a short time span (16 s) under continuous finger impartation and illuminate 39 commercial high-power blue LEDs that were connected in series. Thus, the fabricated SPENG can be used as a green and portable energy source to power up portable electronic devices. Apart from this, the SPENG may also be used as a self-powered energy supply for pacemakers or different types of health care units if properly improvised.
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A flexible nano-engineered natural mineral (carbon dot doped natural microcline) based membrane (MCPV) has been developed, which can efficiently detect the presence of hexavalent chromium (Cr6+) and trivalent iron (Fe3+) ions in water by altering its fluorescence emission. Detailed characterization of the membrane was carried out using XRD, FT-IR spectroscopy, FESEM, TEM, and UV-Vis spectroscopy. Mechanical and temperature stabilities were also investigated. This new-generation sensor membrane is designed in such a way that it does not dissolve in water, keeping the water quality unaffected. The fluorescence studies were conducted at 414 nm and "turn-off" response was observed specifically for Fe3+ at 489 nm. A prominent red shift (530 nm) of the fluorescence maxima takes place when it comes to Cr6+. Figures of merit, such as LOD (8.7 µM for Cr6+ and 18.4 µM for Fe3+) and LOQ (29.1 µM for Cr6+ and 61.6 µM for Fe3+), were evaluated from the linear range (0-60 µM for Cr6+ and 0-30 µM for Fe3+) of the calibration curve (Stern-Volmer plots) showing high sensitivity of this sensing probe toward Cr6+ and Fe3+. Recovery and RSD calculations were done in various real-life water samples on intraday-interday basis to determine the accuracy of the sensor. This work validates the fact that the synthesized sensor membrane is capable of detecting these heavy metals in glutathione environment as well, which could be beneficial for early-stage carcinogen detection in living cells.
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Compuestos de Aluminio/química , Carcinógenos/análisis , Cromo/análisis , Hierro/análisis , Membranas Artificiales , Puntos Cuánticos/química , Silicatos/química , Carbono/química , Teoría Funcional de la Densidad , Agua Potable/análisis , Colorantes Fluorescentes/química , Glutatión/química , Límite de Detección , Modelos Químicos , Simulación del Acoplamiento Molecular , Estanques/análisis , Espectrometría de Fluorescencia/métodos , Aguas Residuales/análisis , Contaminantes Químicos del Agua/análisisRESUMEN
In modern society, massive industrialization escalates environmental degradation by liberating various contaminants into the environment. Hexavalent chromium is a heavy metal that is being discharged from tannery and other industries, resulting in various carcinogenic diseases. This study reports a carbon dot (cdot)-based fluorometric probe for detecting hexavalent chromium in water. This is the very first time that cdots are tailored over the boehmite nanoparticle's surface using an in situ approach. Validation of formation of the nanocomposite has been discussed in detail employing the Rietveld refinement-based X-ray crystallography method. Vibrational spectroscopy and electron microscopy of the sample authenticate the nucleation process and the growth mechanism. The Stern-Volmer approach and time-resolved fluorescence measurements justify the sensitivity of the sensor (â¼58 nM), and selectivity is analyzed by exposing the material to different ionic environments. Density functional theory (DFT) is applied herein to analyze the origin of fluorescence and the sensing mechanism of the probe, which shows that photoinduced electron transfer is responsible for the turn-off-based sensing of Cr(VI). The molecular docking simulation is carried out to ensure the binding of cdots to the binding pocket of the glutathione enzyme, which is responsible for treating reactive oxygen species-mediated DNA damage due to elements such as hexavalent chromium. Time-dependent density functional calculations show that the fluorometric probe is capable of detecting Cr(VI) in living cells making it an early stage chromium-mediated carcinogen detector.
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Carcinógenos/análisis , Cromo/análisis , Teoría Funcional de la Densidad , Colorantes Fluorescentes/química , Nanopartículas/química , Aguas Residuales/química , Carbono/química , Cristalografía por Rayos X , Humanos , Simulación del Acoplamiento Molecular , Tamaño de la Partícula , Puntos Cuánticos/química , Propiedades de SuperficieRESUMEN
In this study, porous fluorescent nanocrystalline erbium doped hydroxyapatite (eHAp) was synthesized via hydrothermal assisted co-precipitation method. Eucalyptus oil (EU), frankincense oil (FO), Tea tree oil (TTO), wintergreen oil (WO) were successfully absorbed into eHAp pellet by vacuum filtration technique using Buckner funnel. Phase crystallization, fluorescence property and microstructure of eHAp were confirmed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Photoluminiscence spectroscopy (PL) and Field emission scanning electron microscopy (FESEM). Strong antimicrobial activity was observed for EU, TTO and WO on both E. coli and S. aureus mediated by cell membrane damage and leakage of cytoplasmic components. The oil absorbed eHAp nanocomposites were found to be moderately biocompatible with normal WI-38 cells up to MIC concentration various time scale. The nanocomposites showed significant cytotoxic activity on breast cancer cell line MDA-MB 468 and the fluorescent property of the eHAp was utilized to visualize internalization of particles in the cells. The release profile of the oils from the eHAp matrix showed pH dependent release indicated that the porous matrix can be used as a suitable carrier for modulated and sustained release of bioactive components. Thus, given the multifunctional attributes these natural essential oil-based nanocomposites show great promise as an alternative to conventional therapeutic treatments.
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Nanocompuestos , Aceites Volátiles , Antibacterianos/farmacología , Durapatita , Escherichia coli , Pruebas de Sensibilidad Microbiana , Aceites Volátiles/farmacología , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus aureus , Difracción de Rayos XRESUMEN
In the modern era, the escalation of heavy metal discharges, especially from the industrial sector, is causing an enormous threat to nature. This article explores the dual sensing of heavy metals (Cr6+ and Fe3+) using a naturally formed microcline based sensor. A nano-sized microcline (M) was obtained via a facile top-down synthesis. In order to enhance the fluorescence property of the material, nitrogenous carbon-dots were loaded into the porous structure of the microcline (MCD) causing a bright blue fluorescence with remarkable stability. Detailed analysis of the composition and structure of the natural nano-sensor was carried out using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and BET analysis. This sensor material is highly selective towards Cr6+ and Fe3+, demonstrating a "turn-off" response in aqueous Fe3+ and a radical red shift of the fluorescence maxima for aqueous Cr6+. Density functional studies suggest that photoinduced electron transfer (PET) based quenching of fluorescence is responsible for these types of fluorescence alteration mechanisms. Efficient sensing of both Cr6+ and Fe3+ in various real-life water samples along with a real wastewater sample is also reported herein. A few studies have previously reported on efficient, natural material-based sensors, but they lack real-life applications due to their complicated synthesis and restricted functionalities. This work manages to overcome those drawbacks in its own fashion, providing a tremendously selective and sensitive (4 µM for Cr6+ and 19 µM for Fe3+) dual fluorescent probe.
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During a survey performed in sapota orchards of India, from 2015 to 2018, symptoms of phyllody, little leaf, flat stem and witches' broom were observed in three states: Karnataka, Kerala and Tripura. The association of phytoplasmas was confirmed in all the symptomatic sapota samples by using nested PCR specific primers (P1/P7, R16F2n/R16R2 and 3Far/3Rev) with amplification of fragments of ~ 1.25 kb and ~ 1.3 kb. Association of three phytoplasma groups, aster yellows with flat stem from Tripura (Lembucherra), clover proliferation with phyllody symptoms at Karnataka (Bengaluru) and bermuda grass white leaf with flat stem and little leaf from Kerala (Thiruvananthapuram) and Tripura (Cocotilla) were confirmed by 16S rRNA gene sequence comparison analysis. Virtual RFLP analysis of 16S rRNA gene sequences using pDRAW32 further classified the sapota phytoplasma isolates into 16SrI-B, 16SrVI-D and 16SrXIV-A subgroups. This is the first report on identification of three phytoplasma groups in sapota in world.
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Visceral leishmaniasis (VL) is endemic in Asia, East and North Africa, South America, and Southern Europe, and is a major public health problem in the Indian subcontinent. Miltefosine received approval in 2002 to treat VL in India, and the Indian National Vector Borne Disease Control Programme later adopted a single dose (10 mg/kg) of liposomal amphotericin B. We report results of a randomized trial comparing the efficacy of combination therapy with an Indian preparation of liposomal amphotericin B (single dose of 7.5 mg/kg) and short-course miltefosine (2.5 mg/kg/day for 14 days; n = 66) in comparison to miltefosine monotherapy (2.5 mg/kg/day for 28 days; n = 78). Nine patients in the miltefosine group and three in the combination therapy group had to discontinue therapy because of serious adverse events. At the end of the therapy, the clinical and parasitological cure rate was 100% in both groups. By per-protocol analysis, by 6 months after completion of treatment, 12 of 69 patients in the miltefosine monotherapy arm (17.4%, 95% CI: 10.24-28%) and none in the combination therapy arm had relapse. Over 5 years of follow-up, 10 patients in the miltefosine monotherapy arm (all within 0.5-2 years after completing therapy) and none in the combination therapy arm experienced post-kala-azar dermal leishmaniasis. Combination therapy offered benefits over miltefosine monotherapy for VL in India.