Piezo-responsive bismuth ferrite nanoparticle-mediated catalytic degradation of rhodamine B and pathogenic E. coli in aqueous medium and its extraction using external magnetic stimulation after successful treatment.

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 ∼ 99%) along with a high rate constant (k ∼ 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 ∼94%. Moreover, the extraction of this catalyst is quite simple. Due to its high remanent magnetization (retentivity ∼0.08 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.

Biocompatible Carbon Dot Decorated α-FeOOH Nanohybrid for an Effective Fluorometric Sensing of Cr (VI) in Wastewater and Living Cells.

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.

Recent advances in piezocatalytic polymer nanocomposites for wastewater remediation.

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.

Development of a Sustainable and Biodegradable Sonchus asper Cotton Pappus Based Piezoelectric Nanogenerator for Instrument Vibration and Human Body Motion Sensing with Mechanical Energy Harvesting Applications.

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 ∼81.2 V; short circuit current, I SC ∼1.0 µA) by continuous finger impartation. Uniform output performance was also obtained by the application of uniform force on the devices (e.g., ∼42 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.

Nanoparticle Size-Dependent Antibacterial Activities in Natural Minerals.

The size-dependent antibacterial activities of three minerals namely; alkali feldspar, calcite and stibnite are reported as examined individually against Escherichia coli and Staphylococcus aureus by evaluating minimum inhibitory concentration (MIC) with colony counting method, along with cell survivability assay (MTT). Each of these minerals were grinded into fine-size fractions-S1 (bulk), S2 (ball milled) and S3 (nanosized) and spectroscopically characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and ultraviolet-visible (UV-Vis) spectroscopy. Antibacterial activity was found to be highest in the nanosized (S3) minerals. Interaction between bacteria and nanosized mineral samples produce intracellular reactive oxygen species (ROS), which might cause higher bacterial mortality. The penetration due to nano-dimension is another significant observation as evidenced by bacterial FESEM micrographs. The current findings thus provide a pathway for future research on antibacterial products retrievable from widely available geological materials. The size dependant antibacterial activity of naturally formed minerals is a new insight to reduce bacterial contamination in living systems.

Curcumin ameliorates the targeted delivery of methotrexate intercalated montmorillonite clay to cancer cells.

Montmorillonite Clay (MMT) is aimed to develop as an orally administrable drug delivery vehicle with enhanced efficacy. Aiming to enhance the therapeutic index of methotrexate, curcumin is concomitantly used with methotrexate in the present study. Being folate antagonist in nature, methotrexate is internalized into cells by folate receptor (FR); which is over-expressed in certain human cancer cells such as cervical carcinoma cells (HeLa). Firstly, montmorillonite Clay (MMT) is organically modified (OMMT) with cetyl trimethyl ammonium bromide (CTAB) and used to intercalate curcumin and methotrexate separately, designated as OMMT-Cur and OMMT-MTX, respectively. XRD pattern demonstrated successful intercalation of therapeutics and an increase in clay interlayer distance facilitated by CTAB. The dissolution kinetics of methotrexate follows Higuchi model for both Simulated Gastric Fluid (SGF) and Simulated Intestinal Fluid (SIF), while the release kinetics for curcumin fitted into Higuchi model for SGF and Hixson-Crowell model for SIF, respectively. OMMT-MTX are able to discriminate FR-positive HeLa cells from FR-negative breast cancer cells (MCF7); irrespective of alike cellular phenotypes. Further, the pre-treatment of HeLa cells with curcumin improves its sensitivity towards methotrexate causing a greater killing of the Hela cells. Together, the results propose the concomitant use of curcumin and methotrexate for successfully targeting highly invasive FR-positive carcinomas by means of folate receptor using MMTs.

Enhancement of quantum efficiency of a dye-sensitized electrochemical cell by using triturated zinc oxide mixed with two organic dyes, azure C and rose bengal

For efficiently utilising solar energy, when suitable nanoparticles are being engineered, triturated zinc oxide an eco-friendly, easily available, low-cost material has been used as an agent for solar energy conversion. Two organic dyes Azure C and Rose bengal having absorption bands in two different spectral regions at 545 nm and 610 nm respectively, were chosen in order to overcome the band absorption limits of each dye and utilise the broad spectrum of solar radiation. The material was mixed with these two dyes in a specially devised electrochemical cell and photovoltage with significant efficiency was generated. The energy conversion efficiency of the cell using three different potencies 6C, 30C and 200C of triturated zinc oxide with the same concentration of two dyes (0.5x10-5 M) in all cases are 0.39%, 0.43% and 0.35% respectively. The efficiency is only 0.15% for the mixed dye under similar conditions.

Effects of homeopathic medicine on physical properties of matter - a classical and QED perspective

Homeopathic medicines affect physical properties of matter which depend on the characteristic and the potency of the medicine1. These effects can be explained from two aspects: (a) classical and (b) quantum electrodynamical. Using three different sets of experiments where homeopathic medicines have affected the physical properties of matter, we have shown how the results can be interpreted from both these points of view. (AU)

Effect of ultrahigh diluted homeopathic medicines on the electrical properties of PVDF-HFP

In an effort to improve the electrical properties of the electroactive Poly(vinylidene fluoridehexafluoropropylene) (PVdF-HFP), we introduced a novel and simple approach to synthesize PVDFHFP composite films by incorporating ultrahigh dilutions of two homeopathic medicines Ferrum metallicum (FM) and Zincum oxidatum (ZO) in different potencies. The homeo-PVDF-composite films (HPCF) were synthesized by simple solution casting technique. XRD, FESEM, FTIR studies were performed to check the presence of nanoparticles in the film. The electrical properties of the HPCF samples get enhanced significantly due to the incorporation of the medicines and the effect increases with the increase in potency of the medicines. (AU)

Effect of ultrahigh diluted homeopathic medicines on the electrical properties of PVDF-HFP

In an effort to improve the electrical properties of the electroactive Poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP), we introduced a novel and simple approach to synthesize PVDFHFP composite films by incorporating ultrahigh dilutions of two homeopathic medicines Ferrum metallicum (FM) and Zincum oxidatum (ZO) in different potencies. The homeo-PVDF-composite films (HPCF) were synthesized by simple solution casting technique. XRD, FESEM, FTIR studies were performed to check the presence of nanoparticles in the film. The electrical properties of the HPCF samples get enhanced significantly due to the incorporation of the medicines and the effect increases with the increase in potency of the medicines.

Derivation of an empirical relation between the size of the nanoparticle and the potency of homeopathic medicines

Homeopathic medicines are often prescribed at very high dilutions and it is a clinically observed fact that the medicinal effect of the drug remains even at these high dilutions. The increase in potency of a medicine due to potentization is still debatable from physico-chemical point of view. Out of various hypotheses to explain this phenomenon, a recent hypothesis, advanced by us and supported by others, is that the size of the constituent particles decreases and eventually achieves nano dimension due to potentization. From the experiments performed by our group, the size of nanoparticles (NPs) of Cuprum metallicum, Zincum oxydatum, Aurum metallicum, Ferrum metallicum and Aconitum napellus (6cH, 30cH and 200cH) have been estimated. A general mathematical expression of the form y = a x-n has been derived which relates the size of NPs (y) with the corresponding potencies (x). There is no method to calculate the accurate potency of the homeopathic medicine, as the potency of a medicine depends to some extent on the method of preparation, for which a standardized procedure is warranted. Also, while handling a medicine, the solvent might evaporate causing a change in the potency. Thus by measuring the size of the NPs and using our proposed standard curve, the potency may be estimated...

Derivation of an empirical relation between the size of the nanoparticle and the potency of homeopathic medicines

Homeopathic medicines are often prescribed at very high dilutions and it is a clinically observed fact that the medicinal effect of the drug remains even at these high dilutions. The increase in potency of a medicine due to potentization is still debatable from physico-chemical point of view. Out of various hypotheses to explain this phenomenon, a recent hypothesis, advanced by us and supported by others, is that the size of the constituent particles decreases and eventually achieves nano dimension due to potentization. From the experiments performed by our group, the size of nanoparticles (NPs) of Cuprum metallicum, Zincum oxydatum, Aurum metallicum, Ferrum metallicum and Aconitum napellus (6cH, 30cH and 200cH) have been estimated. A general mathematical expression of the form y = a x-n has been derived which relates the size of NPs (y) with the corresponding potencies (x). There is no method to calculate the accurate potency of the homeopathic medicine, as the potency of a medicine depends to some extent on the method of preparation, for which a standardized procedure is warranted. Also, while handling a medicine, the solvent might evaporate causing a change in the potency. Thus by measuring the size of the NPs and using our proposed standard curve, the potency may be estimated. (AU)

Antimicrobial efficacy and biocompatibility study of copper nanoparticle adsorbed mullite aggregates.

A mullite based antimicrobial ceramic composite has been developed by simple adsorption of copper nano particle suspension. The physico-chemical properties of samples were characterized by different instruments which showed that the composite is well crystalline with homogeneous distribution of copper nanoparticles on the surface. Antimicrobial study was performed by plate count technique which showed >99% mortality for all the bacterial species studied after 24h of incubation. Minimum inhibitory concentration (MIC) values determined by batch culture process showed considerably low values (in terms of copper content) indicating that mullite matrix plays a role in enhancing the antimicrobial efficacy of the composite. Biocompatibility studies on human cancer cell lines indicated that the composite had negligible toxicity below 100µg/mL of Cu content. Thus the composite can be suitable for developing antimicrobial ceramic wares and therapeutic purposes like treatment of variety of microbial infections.

Development of iron oxide and titania treated fly ash based ceramic and its bioactivity.

The increasing accumulation of fly ash from thermal power plants poses a major problem to the environment. The present work reflects the novel utilization of this profusely available industrial waste in the form of an antibacterial hard ceramic material by treating fly ash with ferric oxide (Fe2O3) and titania (TiO2) during sintering process at 1600 °C. The developed material shows more than 90% bacterial reduction against both Gram-positive and Gram-negative bacteria. The mechanism of their antibacterial action was studied by transmission electron microscopy (TEM) image analysis of the bacterial cross-section. The developed ceramic material acquires hardness due to the enhancement of the natural mullite content in the matrix. The mullite content and the crystallinity of mullite have shown their increasing trend with increasing concentration of the metal oxide during sintering process. A maximum of ~37% increase in mullite was obtained for 7% w/w Fe2O3 and TiO2. Metal oxide lowered the activation energy of the reaction and enhanced the reaction rate of alumina (Al2O3)-silica (SiO2) to form mullite which increases the hardness. The study highlights novel utilization of fly ash as a hard ceramic antibacterial product (bioceramics) for both structural and hygiene applications in an eco-friendly way.

A study on the phytotoxicity of nano mullite and metal-amended nano mullite on mung bean plants.

The presence of engineered nanoparticles is continuously increasing in our environment and causing potential risks to the ecosystem. Researchers from various fields report many articles on the effects of different nanoparticles on plants, animals and microorganisms. Here we have studied for the first time the effect of nano mullite (NMu) and their metal- amended derivatives on the growth of mung bean plants. Results shows that the metal- amended NMu exerts adverse effects on the growth and biomass production of plants compared to NMu. For toxicity studies, we measured the germination index and relative root elongation, while leakage of electrolytes and root oxidizability were measured to study the effect of NMu on mung bean seeds and seedling tissues. Translocation and accumulation of NMu within different parts of the plant body were proved by elemental analysis of dried plant samples.

Enhancement of storage capacity and conversion efficiency of photoelectrochemical cells: effect of dyes adsorbed on carbon nano tubes.

We report here our studies on photoelectrochemical (PEC) cells where two commonly used photosensitive dyes, thionine and Rose Bengal were used as photosensitizers for conversion of light energy to electrical energy. The performance of the cells increased radically in presence of oxidized multiwalled carbon nano tubes (OMWCNTs) as reflected by the values of conversion efficiency (∼3.69%) and open circuit voltage (∼548.9 mV). To understand the role of OMWCNTs in enhancing the performance of the cells, the spectral study of dye­OMWCNT mixed systems were performed. The absorption spectra indicated more absorption of incident photons in presence of OMWCNT, whereas the infrared spectra suggested that the basic structure of dyes remained unaltered. The spectral studies implied that the dye molecules got adsorbed on OMWCNTs side walls causing efficient absorption of the incident light quanta. Moreover, insertion of planar lipid membrane (PLM) separating the two chambers of PEC cell could effectively counteract the recombination of photodissociated charges and thereby caused better storage capacity of the PEC cells with further increase in efficiency.