Low auto‐fluorescence fabrication methods for plastic nanoslits

Plastic nanofluidic devices are becoming increasingly important for biological and chemical applications. However, they suffer from high auto‐fluorescence when used for on‐chip optical detection. In this study, the auto‐fluorescence problem of plastic nanofluidic devices was remedied by newly developed fabrication methods that minimise their auto‐fluorescence: one by depositing a gold (Au) layer on them, the other by making them ultra‐thin. In the first method, the Au layer [minimum thickness is 40 nm on 150 μm SU‐8, 50 nm on 1 mm polyethylene terephthalate (PET), and 40 on 2 nm polymethyl methacrylate (PMMA)] blocks the auto‐fluorescence of the polymer; in the second method, auto‐fluorescence is minimised by making the chips ultra‐thin, selected operating thickness of SU‐8 is 20 μm, for PET it is 150 μm, and for PMMA it is 0.8 mm.Inspec keywords: nanofluidics, nanofabrication, plastics, optical sensors, nanosensors, biological techniques, gold, biosensorsOther keywords: autofluorescence fabrication methods, plastic nanoslits, plastic nanofluidic devices, biological applications, chemical applications, on‐chip optical detection, gold layer, SU‐8, polyethylene terephthalate, size 20 mum, size 150 mum, size 0.8 mm, Au     

Investigation of the morphological cell structures and their optical significances of Aeshna cyanea

The transparent wing of the dragonfly Aeshna cyanea has been investigated using scanning electron microscopy (SEM), optical microscopy (OPM), energy‐dispersive X‐ray spectroscopy (EDS) and reflectance spectroscopy. Four cells (D1–D4) were studied and classified according to their general morphology. The OPM depicted the vein‐joint characterised by the distribution of resilin. EDS technique showed common elements such as carbon, oxygen, and chlorine. SEM analysis revealed thin membranes reinforced with a network of hallow veins. Spikes and round shape of microstructures were identified. The roughness of the pruinosity was estimated, which indicates the shape and curvature of the microstructures that essentially play a significant role in the optical response observed. The study can be essential to design and improve micro‐air vehicles.Inspec keywords: bio‐optics, optical microscopy, biomembranes, light reflection, X‐ray chemical analysis, scanning electron microscopy, crystal microstructureOther keywords: transparent wing, EDS technique, SEM analysis, morphological cell structures, optical microscopy, dragonfly Aeshna cyanea, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, reflectance spectroscopy, vein‐joint characterization, resilin distribution, carbon, oxygen, chlorine, thin membrane reinforced hallow vein network, microstructure spikes, microstructure round shape, micro‐air vehicles     

Excluded volume effects in on‐ and off‐lattice reaction–diffusion models

Mathematical models are important tools to study the excluded volume effects on reaction–diffusion systems, which are known to play an important role inside living cells. Detailed microscopic simulations with off‐lattice Brownian dynamics become computationally expensive in crowded environments. In this study, the authors therefore investigate to which extent on‐lattice approximations, the so‐called cellular automata models, can be used to simulate reactions and diffusion in the presence of crowding molecules. They show that the diffusion is most severely slowed down in the off‐lattice model, since randomly distributed obstacles effectively exclude more volume than those ordered on an artificial grid. Crowded reaction rates can be both increased and decreased by the grid structure and it proves important to model the molecules with realistic sizes when excluded volume is taken into account. The grid artefacts increase with increasing crowder density and they conclude that the computationally more efficient on‐lattice simulations are accurate approximations only for low crowder densities.Inspec keywords: reaction‐diffusion systems, cellular biophysics, biodiffusion, Brownian motion, cellular automata, molecular biophysics, molecular configurationsOther keywords: crowder density, grid artefacts, grid structure, crowded reaction rates, artificial grid, randomly distributed obstacles, crowding molecules, cellular automata models, on‐lattice approximations, crowded environments, off‐lattice Brownian dynamics, detailed microscopic simulations, living cells, mathematical models, off‐lattice reaction‐diffusion models, on‐lattice reaction‐diffusion models, excluded volume effects     

Optical detection of CA 15.3 breast cancer antigen using CdS quantum dot

The present study focus on optical sensing of breast cancer antigen 15.3 (CA 15.3) using cadmium sulphide quantum dot (CdS‐QD) in saline and serum samples spiked with antigen. The surface of CdS‐QD was modified by cysteamine capping followed by tagging of CA 15.3 antibody. The samples were characterised using UV‐visible absorption spectroscopy (UV‐VIS Spectroscopy), Fourier transform infrared spectroscopy (FTIR), high‐resolution transmission electron microscopy (HRTEM) attached with energy‐dispersive X‐ray spectroscopy, phase contrast inverted epi‐fluorescence microscopy and photoluminescence (PL) spectrophotometry (EDS). The CdS‐QD showed a mean diameter of 3.02 ± 0.6 nm. The complex formed after antigen‐antibody interaction resulted in distinguishable optical and fluorescence intensity with respect to varying concentration of antigen. The PL study revealed that CA 15.3 antibody labelled CdS QD can detect CA 15.3 tumour marker even at very low concentration of 0.002 KU/L with a constant response time of 15 min. This study clearly indicates that detection of CA 15.3 at low concentration is possible using surface modified CdS QD in serum samples and can find immense applications in biosensor development for detection of breast cancer marker similar to various automated detection kits available in market.Inspec keywords: semiconductor quantum dots, cadmium compounds, II‐VI semiconductors, wide band gap semiconductors, cancer, tumours, optical sensors, biosensors, biomedical equipment, visible spectra, ultraviolet spectra, Fourier transform infrared spectra, transmission electron microscopy, X‐ray chemical analysis, fluorescence, optical microscopy, photoluminescence, proteins, molecular biophysics, nanosensors, nanomedicine, nanoparticlesOther keywords: optical detection, CA 15.3 breast cancer antigen, optical sensing, cadmium sulphide quantum dot, saline samples, serum samples, cysteamine capping, CA 15.3 antibody, UV‐visible absorption spectroscopy, Fourier transform infrared spectroscopy, high‐resolution transmission electron microscopy, energy dispersive X‐ray spectroscopy, phase contrast inverted epifluorescence microscopy, photoluminescence spectrophotometry, antigen‐antibody interaction, fluorescence intensity, optical intensity, CA 15.3 tumour marker, surface modified CdS QD, biosensor development, time 15 min, CdS     

Nano‐biosensor based on reduced graphene oxide and gold nanoparticles,for detection of phenylketonuria‐associated DNA mutation

Phenylketonuria (PKU)‐associated DNA mutation in newborn children can be harmful to his health and early detection is the best way to inhibit consequences. A novel electrochemical nano‐biosensor was developed for PKU detection, based on signal amplification using nanomaterials, e.g. gold nanoparticles (AuNPs) decorated on the reduced graphene oxide sheet on the screen‐printed carbon electrode. The fabrication steps were checked by field emission scanning electron microscope imaging as well as cyclic voltammetry analysis. The specific alkanethiol single‐stranded DNA probes were attached by self‐assembly methodology on the AuNPs surface and Oracet blue was used as an intercalating electrochemical label. The results showed the detection limit of 21.3 fM and the dynamic range of 80–1200 fM. Moreover, the selectivity results represented a great specificity of the nano‐biosensor for its specific target DNA oligo versus other non‐specific sequences. The real sample simulation was performed successfully with almost no difference than a synthetic buffer solution environment.Inspec keywords: biosensors, nanosensors, nanoparticles, graphene compounds, gold, nanomedicine, DNA, molecular biophysics, biomedical equipment, electrochemical sensors, electrochemical electrodes, field emission scanning electron microscopy, voltammetry (chemical analysis), self‐assembly, biochemistryOther keywords: reduced graphene oxide, gold nanoparticles, phenylketonuria‐associated DNA mutation, newborn children, electrochemical nanobiosensor, signal amplification, nanomaterials, reduced graphene oxide sheet, screen‐printed carbon electrode, field emission scanning electron microscopy imaging, cyclic voltammetry, alkanethiol single‐stranded DNA probes, self‐assembly methodology, Oracet blue, intercalating electrochemical label, Au‐CO     

Investigation of graphene‐on‐metal substrates for SPR‐based sensor using finite‐difference time domain

In this study, the authors investigated the effects of a single layer graphene as a coating layer on top of metal thin films such as silver, gold, aluminum and copper using finite‐difference time domain method. To enhance the resolution of surface plasmon resonance (SPR) sensor, it is necessary to increase the SPR reflectivity and decrease the full‐width‐half maximum (FWHM) of the SPR curve so that there is minimum uncertainty in the determination of the resonance dip. Numerical data was verified with analytical and experimental data where all the data were in good agreement with resonance angle differing in <10% due to noise present in components such as humidity and temperature. In further analysis, reflectivity and FWHM were compared among four types of metal with various thin film thicknesses where graphene was applied on top of the metal layers, and data was compared against pure conventional metal thin films. A 60 nm‐thick Au thin film results in higher performance with reflectivity of 92.4% and FWHM of 0.88° whereas single layer graphene‐on‐60 nm‐thick Au gave reflectivity of 91.7% and FWHM of 1.32°. However, a graphene‐on‐40 nm‐thick Ag also gave good performance with narrower FWHM of 0.88° and reflection spectra of 89.2%.Inspec keywords: graphene, surface plasmon resonance, finite difference time‐domain analysis, reflectivity, metallic thin films, silver, gold, aluminium, copper, chemical sensors, biological techniquesOther keywords: graphene‐on‐metal substrates, SPR‐based sensor, finite‐difference time domain, metal thin films, surface plasmon resonance sensor, SPR curve, resonance angles, reflectivity, C, Ag, Au, Al, Cu     

Polyelectrolyte multilayers for bio‐applications: recent advancements

The synergistic relationship between structure and the bulk properties of polyelectrolyte multilayer (PEM) films has generated tremendous interest in their application for loading and release of bioactive species. Layer‐by‐layer assembly is the simplest, cost effective process for fabrication of such PEMs films, leading to one of the most widely accepted platforms for incorporating biological molecules with nanometre precision. The bulk reservoir properties of PEM films render them a potential candidate for applications such as biosensing, drug delivery and tissue engineering. Various biomolecules such as proteins, DNA, RNA or other desired molecules can be incorporated into the PEM stack via electrostatic interactions and various other secondary interactions such as hydrophobic interactions. The location and availability of the biological molecules within the PEM stack mediates its applicability in various fields of biomedical engineering such as programmed drug delivery. The development of advanced technologies for biomedical applications using PEM films has seen rapid progress recently. This review briefly summarises the recent successes of PEM being utilised for diverse bio‐applications.Inspec keywords: polymer electrolytes, multilayers, polymer films, molecular biophysics, biomedical materials, biochemistryOther keywords: bioapplications, polyelectrolyte multilayer films, bioactive species, layer‐by‐layer assembly, biological molecules, biosensing, drug delivery, tissue engineering, biomolecules, proteins, DNA, RNA, electrostatic interactions, secondary interactions, hydrophobic interactions, biomedical engineering, programmed drug delivery, biomedical applications, PEM films     

Enhanced cytotoxic activity of AgNPs on retinoblastoma Y79 cell lines synthesised using marine seaweed Turbinaria ornata

Retinoblastoma is the most common intraocular malignancy basically occurs among children below five. Certain ocular treatments such as surgery, radiation therapy and chemotherapy are more likely to cause side effects. Here, a rapid method of synthesising silver nanoparticles (AgNPs) from the brown seaweed Turbinaria ornata and its cytotoxic efficacy against the retinoblastoma Y79 cell lines was studied. The AgNPs synthesis was determined by Ultraviolet–visible spectroscopy and was further characterised by X‐ray diffraction, High‐resolution transmission electron microscopy, zeta potential, Energy‐dispersive X‐ray spectroscopy, thermogravimetric analysis, Fourier transform infrared spectrum and inductively coupled plasma‐mass spectroscopy techniques. The synthesised AgNPs were found to be very stable and finely dispersed. The total phenolic content of the synthesised AgNPs was estimated at 43±2.52 mg/g gallic acid equivalent and the nanoparticles exhibited good scavenging activity analysed by 2, 2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulphonic acid) assay. Moreover, cytotoxicity of synthesised AgNPs against in vitro retinoblastoma Y79 cell lines showed a dose‐dependent response with an inhibitory concentration (IC₅₀) of 10.5 µg/mL. These results suggest that AgNPs could be a promising anticancer agent with enhanced activity in ocular treatment.Inspec keywords: toxicology, silver, nanoparticles, cellular biophysics, cancer, nanomedicine, nanofabrication, X‐ray diffraction, transmission electron microscopy, electrokinetic effects, X‐ray chemical analysis, thermal analysis, Fourier transform infrared spectra, ultraviolet spectra, visible spectra, biomedical materials, mass spectroscopic chemical analysisOther keywords: cytotoxic activity, marine seaweed Turbinaria ornata, intraocular malignancy, silver nanoparticles, brown seaweed Turbinaria ornata, X‐ray diffraction, high‐resolution transmission electron microscopy, zeta potential, EDAX, thermogravimetric analysis, Fourier transform infrared spectrum, inductively coupled plasma‐mass spectroscopy, phenolic content, gallic acid, scavenging activity, in vitro retinoblastoma Y79 cell lines, dose‐dependent response, inhibitory concentration, anticancer agent, 2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulphonic acid) assay, nanotechnology‐based cancer diagnosis, ocular tumour treatment, ultraviolet‐visible spectroscopy, Ag     

In‐situ fabrication of zirconium–titanium nano‐composite and its coating on Ti‐6Al‐4V for biomedical applications

In this study, nanocomposite powder consisting of zirconia and titania (Zr–Ti) have been synthesised by sol–gel method, with the aim of protecting Ti‐6Al‐4V surface. A simple and low cost electrophoretic deposition (EPD) technique has been employed for coating the nanocomposite material on Ti‐6Al‐4V. The prepared nanocomposite powder was characterised for its functional groups, phase purity, surface topography by Fourier transform infrared spectroscopy, powder X‐ray diffraction and scanning electron microscopy. Further, the biocompatibility nature of the composite powder was studied by [3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide] colorimetric assay and fluorescence analysis with MG63 osteoblast cell lines. The electrochemical behaviour of composite coating was investigated by potentiodynamic polarization and electrochemical impedance method. The results obtained from the electrochemical techniques indicate more corrosion resistance behaviour with increase of R _ct value with the corresponding decrease in R _dl values. From the above findings, the composite coating acts as a barrier layer against corrosion by preventing the leaching of metal ions from a dense and defect free coating. A scratch test analyser was used to assess the integrity of the coating; the lower traction force value of composite coating with increase in load has confirmed the presence of thick adherent layer on the substrate.Inspec keywords: zirconium compounds, titanium compounds, titanium alloys, aluminium alloys, vanadium alloys, nanofabrication, nanocomposites, nanoparticles, sol‐gel processing, electrophoretic coating techniques, surface topography, Fourier transform infrared spectra, X‐ray diffraction, scanning electron microscopy, X‐ray chemical analysis, fluorescence, cellular biophysics, biomedical materials, electrochemical impedance spectroscopy, corrosion resistance, corrosion protection, corrosion protective coatings, adhesionOther keywords: in‐situ fabrication, zirconium‐titanium nanocomposite powder, biomedical applications, zirconia, titania, sol‐gel method, electrophoretic deposition, EPD, functional groups, phase purity, surface topography, Fourier transform infrared spectroscopy, powder X‐ray diffraction, scanning electron microscopy, energy dispersive X‐ray analysis, biocompatibility, 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide colorimetric assay, acridine range fluorescence analysis, MG63 osteoblast cell lines, electrochemical behaviour, composite coating, potentiodynamic polarization, electrochemical impedance spectroscopy, corrosion resistance, barrier layer, leaching, defect free coating layer, scratch test analysis, adherent layer, TiAlV‐ZrO₂ ‐TiO₂      

Electrophoretic deposition of hydroxyapatite‐shrimp crusts nanocomposite thin films for bone implant studies

Hydroxyapatite‐shrimp crusts nanocomposite thin films were deposited on titanium substrates by electrophoretic technique, under different preparation conditions, for bone implant applications. Fourier transform infrared spectrometer, atomic force microscope, X‐ray diffraction (XRD), optical microscope, and scanning electron microscope were employed to characterise the synthesised films. Vickers’ micro‐hardness measurements revealed a value of 502 HV for the hydroxyapatite films and 314.55 HV for the nanocomposite films. XRD results confirmed the polycrystalline nature of the hydroxyapatite and hydroxyapatite‐shrimp nanocomposite films. The in‐vitro bioactivity test of the synthesised films in simulated body fluid showed very low dissolution rate. Antibacterial activity of synthesised films was investigated against E. coli bacteria.Inspec keywords: electrophoretic coating techniques, thin films, nanocomposites, antibacterial activity, bone, prosthetics, nanomedicine, calcium compounds, bioceramics, nanofabrication, Fourier transform infrared spectra, atomic force microscopy, X‐ray diffraction, optical microscopy, scanning electron microscopy, Vickers hardness, microhardness, microorganisms, dissolvingOther keywords: Ti, Ca₁₀ (PO₄)₆ (OH)₂ , E. coli bacteria, antibacterial activity, dissolution rate, simulated body fluid, in‐vitro bioactivity test, polycrystalline nature, Vickers microhardness measurements, XRD, scanning electron microscopy, optical microscopy, X‐ray diffraction, atomic force microscopy, Fourier transform infrared spectrometer, bone implant applications, titanium substrates, hydroxyapatite‐shrimp crust nanocomposite thin films, electrophoretic deposition     

Facile one‐pot hydrothermal synthesis of stable and biocompatible fluorescent carbon dots from lemon grass herb

Luminescent carbon‐based nanomaterials hold great promise due to their stable photo‐physical behaviour, biocompatibility and lower toxicity. This work involves economic and facile one‐pot green synthesis of water‐soluble nanostructures from lemon grass (LGNS) [Cymbopogon citratus (DC) Stapf] as carbon source. High‐resolution transmission electron microscopy confirmed the formation of LGNS with lattice spacing of 0.23 nm matching low‐dimensional graphitic structures. The strong absorption exhibited at 278 nm could be attributed to л‐states of sp² /sp³ hybridisation in carbon nanostructures. Fluorescence spectroscopy of LGNS exhibited strong excitation‐dependent emission properties over a broad range of wavelengths from 300 to 600 nm. Quantitatively, these LGNS were estimated to have quantum yield of 23.3%. Biomass derived LGNS could be potentially exploited for wide variety of applications like bioimaging, up‐conversion, drug delivery and optoelectronic devices. To this extent, synthesised LGNS were used to image yeast cells via multicolour/multi‐excitation fluorescence imaging.Inspec keywords: fluorescence, carbon, nanofabrication, photoluminescence, toxicology, transmission electron microscopy, cellular biophysics, biomedical optical imaging, nanomedicine, biomedical materials, microorganisms, liquid phase depositionOther keywords: one‐pot hydrothermal synthesis, biocompatible fluorescent carbon dots, lemon grass herb, luminescent carbon‐based nanomaterials, stable photophysical behaviour, toxicity, water‐soluble nanostructures, carbon source, high‐resolution transmission electron microscopy, low‐dimensional graphitic structures, hybridisation, carbon nanostructures, fluorescence spectroscopy, excitation‐dependent emission properties, biomass derived LGNS, bioimaging, drug delivery, optoelectronic devices, yeast cell image, multicolour‐multiexcitation fluorescence imaging, C     

Fabrication challenges and perspectives on the use of carbon‐electrode dielectrophoresis in sample preparation

The focus of this review is to assess the current status of three‐dimensional (3D) carbon‐electrode dielectrophoresis (carbonDEP) and identify the challenges currently preventing it from its use in high‐throughput applications such as sample preparation for diagnostics. The use of 3D electrodes over more traditional planar ones is emphasised here as a way to increase the throughput of DEP devices. Glass‐like carbon electrodes are derived through the carbonisation of photoresist structures made using photolithography. These biocompatible carbon electrodes are not ideal electrical conductors but are more electrochemically stable than noble metals such as gold and platinum. They are also significantly less expensive than common electrode materials, both in terms of material cost and fabrication process. CarbonDEP has been demonstrated for the manipulation of microorganisms and biomolecules. This review is divided in three main sections: (i) carbonDEP fabrication process; (ii) applications using 3D carbonDEP; and (iii) challenges and perspectives on the use of carbonDEP for high‐throughput applications.Inspec keywords: electrophoresis, electrochemical electrodes, photoresists, electrochemistry, microorganisms, biological specimen preparationOther keywords: sample preparation, three‐dimensional carbon‐electrode dielectrophoresis, high‐throughput applications, diagnostics, 3D electrodes, DEP devices, glass‐like carbon electrodes, carbonisation, photoresist structures, photolithography, biocompatible carbon electrodes, electrochemical stability, electrode materials, material cost, fabrication process, microorganisms, biomolecules, carbonDEP fabrication, C     

Synthesis of Co3 O4 /graphene nanocomposite using paraffin wax for adsorption of methyl violet in water

This study discusses the use of Co₃ O₄ impregnated graphene (CoOIG) as an efficient adsorbent for the removal of methyl violet (MV) dye from wastewater. CoOIG nanocomposites have been prepared by pyrolyzing paraffin wax with cobalt acetate. The synthesised nanocomposite was characterised by X‐ray diffraction, field emission scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscope, Raman spectroscopy, and Brunauer–Emmett–Teller isotherm studies. The above studies indicate that the composites have cobalt oxide nanoparticles of size 51–58 nm embedded in the graphene nanoparticles. The adsorption studies were conducted with various parameters, pH, temperature and initial dye concentration, adsorbent dosage and contact time by the batch method. The adsorption of MV dye by the adsorbent CoOIG was about 90% initially at 15 min and 98% dye removal at pH 5. The data were fitted in Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich and Sips isotherm models. Various thermodynamic parameters like Gibbs free energy, enthalpy, and entropy of the on‐going adsorption process have also been calculated.Inspec keywords: cobalt compounds, graphene, nanoparticles, nanocomposites, nanofabrication, adsorption, dyes, scanning electron microscopy, field emission electron microscopy, transmission electron microscopy, Raman spectra, Fourier transform infrared spectra, free energy, enthalpy, entropyOther keywords: nanocomposite, paraffin wax, adsorption, methyl violet dye, water, X‐ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, Brunauer‐Emmett‐Teller isotherm, cobalt oxide nanoparticles, graphene nanoparticles, thermodynamic parameters, Gibbs free energy, enthalpy, entropy, Co₃ O₄ ‐C     

Laser‐induced heating for in situ DNA replication and detection in microchannels

This study proposes a method for in situ local deoxyribonucleic acid (DNA) replication and detection in a long DNA strand through laser‐induced heating and strong avidin–biotin binding. To achieve the target DNA replication, dielectrophoresis was generated to stretch and immobilise DNA strands on both ends of the electrode. Subsequently, local DNA sequences were replicated using thermal cycles generated by laser‐induced heating. Replicated double‐stranded DNA products were captured in situ on a solid surface and detected using the fluorescence intensity of quantum dots (Qdots). The results revealed that after six laser‐induced thermal cycles, the replicated local DNA sequence could be detected by analysing the difference between Qdot fluorescent intensity before and after replication. The proposed method is expected to improve the efficiency of biosample gene sequence analysis.Inspec keywords: DNA, molecular biophysics, fluorescence, electrophoresis, biochemistry, molecular configurations, quantum dots, laser beam applications, biothermicsOther keywords: laser‐induced heating, long DNA strand, target DNA replication, DNA strands, local DNA sequences, thermal cycles, replicated double‐stranded DNA products, replicated local DNA sequence, in situ DNA replication, in situ local deoxyribonucleic acid replication, strong avidin‐biotin binding, biosample gene sequence analysis, Qdot fluorescent intensity, laser‐induced thermal cycles     

Alyssum lepidium mucilage as a new source for electrospinning: production and physicochemical characterisation

The electrospinning technique was used for the nanofiber production of Alyssum lepidium mucilage with acetic acid and polyvinyl alcohol (PVA) polymer. Some parameters such as voltage, polymer concentration, tip‐to‐collector distance, and feed rate were optimised and applied for the fabrication of the nanofiber membranes of the seeds mucilage. The scanning electron microscopy images were used to find the optimised conditions for the electrospinning process. It was found that the aqueous solution of Alyssum mucilage/PVA (80:20), voltage (18 kV), polymer concentration (50%), tip‐to‐collector distance (10 cm) and feed rate (0.125 ml/h) could be successfully used to obtain uniform nanofibers with diameters as low as 139.9 nm. X‐ray diffraction and Fourier transform infrared spectrometer analysis also proved the presence of the alyssum mucilage/PVA nanofiber. In this study, the used electrospun procedure was biodegradable, inexpensive, non‐toxic, and maintainable enough to optimise the mucilage nanofiber fabrication as a new source, thereby improving the potential application of the nanofiber biomembrane in filtration and medical systems with biocompatible and biodegradable properties.Inspec keywords: electrospinning, nanofibres, nanofabrication, polymer fibres, scanning electron microscopy, X‐ray diffraction, Fourier transform infrared spectraOther keywords: Alyssum lepidium mucilage, electrospinning, physicochemical characterisation, nanofiber production, acetic acid, polyvinyl alcohol, PVA polymer, polymer concentration, tip‐to‐collector distance, feed rate, scanning electron microscopy, X‐ray diffraction, Fourier transform infrared spectrometer analysis, voltage 18 kV, distance 10 cm     

Green synthesis of copper oxide nanoparticles and mosquito larvicidal activity against dengue,zika and chikungunya causing vector Aedes aegypti

In the present study, high purity copper oxide nanoparticles (NPs) were synthesised using Tridax procumbens leaf extract. Green syntheses of nano‐mosquitocides rely on plant compounds as reducing and stabilising agents. Copper oxide NPs were characterised using X‐ray diffraction (XRD) analysis, Fourier transform infrared (FT‐IR), Field‐emission scanning electron microscopy with energy dispersive spectroscopy, Ultraviolet–visible spectrophotometry and fluorescence spectroscopy. XRD studies of the NPs indicate crystalline nature which was perfectly matching with a monoclinic structure of bulk CuO with an average crystallite size of 16 nm. Formation of copper oxide NPs was confirmed by FT‐IR studies and photoluminescence spectra with emission peaks at 331, 411 and 433 nm were assigned to a near‐band‐edge emission band of CuO in the UV, violet and blue region. Gas chromatography–mass spectrometry studies inferred the phytochemical constituents of the leaf extract. Larvicidal activity of synthesised NPs using T. procumbens leaf extract was tested against Aedes aegypti species (dengue, chikungunya, zika and yellow fever transmit vector).Inspec keywords: photoluminescence, spectrophotometry, thermal analysis, chromatography, nanoparticles, antibacterial activity, field emission electron microscopy, microorganisms, wide band gap semiconductors, scanning electron microscopy, X‐ray diffraction, copper compounds, ultraviolet spectra, nanofabrication, X‐ray chemical analysis, crystallites, visible spectra, field emission scanning electron microscopy, nanobiotechnology, semiconductor materials, semiconductor growth, fluorescence, mass spectraOther keywords: energy dispersive spectroscopy, ultraviolet–visual spectrophotometry, fluorescence spectroscopy, chikungunya, green synthesis, mosquito larvicidal activity, zika, X‐ray diffraction analysis, field‐emission scanning electron microscopy, XRD, gas chromatography–mass spectrometry, copper oxide nanoparticles, dengue, tridax procumben leaf extract, nanomosquitocides, FTIR, monoclinic structure, crystallite size, photoluminescence spectra, near‐band‐edge emission band, phytochemical constituents, Aedes aegypti species, yellow fever transmit vector, CuO     

Green synthesis of ZnO nanoparticles by Olive (Olea europaea)

Green synthesis of nanoparticles is superior to physical and chemical methods as it is environment‐friendly and cost‐effective. The present study was carried out for inducing nanoparticles synthesis by zinc nitrate in the leaves extracts of olive. Further leaves extracts were evaluated for antiradical scavenging activity by 1, 1‐diphenyl‐2‐picryl‐hydrazyl assay. Morphological and structural properties of the synthesised ZnO nanoparticles have been characterised using UV‐Vis spectrophotometer, FTIR, TEM, XRD and dynamic light scattering (DLS) analysis. Further, zinc oxide nanoparticles were evaluated for antiradical scavenging activity by capacity of total antioxidant assay. Synthesised ZnO nanoparticles were confirmed by the absorption maxima at the wavelength of 370 nm. TEM image revealed that ZnO nanoparticles were spherical with average size 41 nm. FTIR investigation suggested that the flavonoids, glycosides, proteins and phenols molecules can play an important role in the stabilisation of ZnO nanoparticles.Inspec keywords: zinc compounds, II‐VI semiconductors, wide band gap semiconductors, nanoparticles, nanofabrication, ultraviolet spectra, visible spectra, Fourier transform infrared spectra, transmission electron microscopy, X‐ray diffraction, light scatteringOther keywords: zinc oxide nanoparticles, green synthesis, physical method, chemical method, zinc nitrate, antiradical scavenging activity, 1, 1‐diphenyl‐2‐picryl‐hydrazyl assay, morphological properties, structural properties, UV‐vis spectrophotometer, FTIR, TEM, XRD, dynamic light scattering analysis, flavonoids, glycosides, proteins, phenols molecules, Olea europaea, ZnO     

Latent factor analysis facilitates modelling of oncogenic genes for colon adenocarcinoma

Identification of oncogenic genes from a large sample number of genomic data is a challenge. In this study, a well‐established latent factor model, Bayesian factor and regression model, are applied to predict unknown colon cancer related genes from colon adenocarcinoma genomic data. Four important latent factors were addressed by the latent factor model, focusing on characterisation of heterogeneity of expression patterns of specific oncogenic genes by using microarray data of 174 colon cancer patients. Based on the fact that variables included in the same latent factor have some common characteristics and known cancer related genes in Online Mendelian Inheritance in Man, the authors found that the four latent factors can be employed to predict unknown colon cancer related genes that were never reported in the literature. The authors validated 15 identified genes by checking their somatic mutations of the same patients from DNA sequencing data.Inspec keywords: Bayes methods, biological organs, cancer, DNA, genetics, genomics, lab‐on‐a‐chip, medical diagnostic computing, molecular biophysics, physiological models, regression analysisOther keywords: latent factor analysis, oncogenic genes, colon adenocarcinoma, genomic data, Bayesian factor, colon cancer related genes, heterogeneity, expression patterns, DNA microarray data, Online Mendelian Inheritance in Man, somatic mutations, DNA sequencing data     

Improved experimental time of ultra‐large bioassays using a parallelised microfluidic biochip architecture/scheduling

Digital microfluidic is an emerging technology to reduce the cost and time of experiments and improve the flexibility, automate‐ability and correctness of biochemical assays. In many of applications such as drug discovery and DNA profiling, a large number of bio‐operations (e.g. the chemical operations used in biology applications) must be done. In these applications, parallelising the operations will be critical in accuracy and cost of the process and digital microfluidic biochips can be considered as a reasonable platform. In this study, a new microfluidic architecture and the corresponding CAD flow is introduced to parallelise the assays on this platform. The authors implemented the proposed architecture and evaluated it using the large real bioassays. The authors’ simulations show that the degree‐of‐parallelism and speed of bioassays are increased more than 4× and the improvements will be better for larger assays. This contribution can open new horizons in drug testing, biology experiments and medical diagnosis operations that contain iterative, time‐consuming and labour experiments.Inspec keywords: microfluidics, lab‐on‐a‐chip, biochemistry, bioMEMS, biomedical equipment, CADOther keywords: biochemical assays, medical diagnosis operations, biology experiments, drug testing, CAD flow, parallelised microfluidic biochip architecture‐scheduling, ultralarge bioassays     

Biofabrication of silver nanoparticles using bacteria from mangrove swamp

The last decade has observed a rapid advancement in utilising biological system towards bioremediation of metal ions in the form of respective metal nanostructures or microstructures. The process may also be adopted for respective metal nanoparticle biofabrication. Among different biological methods, bacteria‐mediated method is gaining great attention for nanoparticle fabrication due to their eco‐friendly and cost‐effective process. In the present study, silver nanoparticle (AgNP) was synthesised via continuous biofabrication using Aeromonas veronii, isolated from swamp wetland of Sunderban, West Bengal, India. The biofabricated AgNP was further purified to remove non‐conjugated biomolecules using size exclusion chromatography, and the purified AgNPs were characterised using UV–visible spectroscopy, X‐ray diffraction, field emission scanning electron microscopy and transmission electron microscopy (TEM). Additionally, the presence of proteins as capping and stabilising agents was confirmed by the amide‐I and amide‐II peaks in the spectra obtained using attenuated total reflection Fourier transform infrared spectroscopy. The size of biofabricated AgNP was 10–20 nm, as observed using TEM. Additionally, biofabricated AgNP shows significant antibacterial potential against E. coli and S. aureus. Hence, biofabricated AgNP using Aeromonas veronii, which found resistant to a significant concentration of Ag ion, showed enhanced antimicrobial activity compared to commercially available AgNP.Inspec keywords: silver, nanoparticles, microorganisms, nanofabrication, purification, chromatography, ultraviolet spectra, visible spectra, X‐ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, proteins, molecular biophysics, biochemistry, molecular configurations, attenuated total reflection, Fourier transform infrared spectra, particle size, antibacterial activity, biomedical materials, nanomedicineOther keywords: capping agents, stabilising agents, amide‐I peaks, amide‐II peaks, attenuated total reflection Fourier transform infrared spectroscopy, antibacterial potential, E. coli, S. aureus, Aeromonas veronii, antimicrobial activity, size 10 nm to 20 nm, Ag, proteins, TEM, transmission electron microscopy, field emission scanning electron microscopy, X‐ray diffraction, UV‐visible spectroscopy, size exclusion chromatography, nonconjugated biomolecules, purification, swamp wetland, Aeromonas veronii, cost‐effective process, eco‐friendly, bacteria‐mediated method, biological methods, metal nanoparticle biofabrication, microstructures, metal nanostructures, metal ions, bioremediation, biological system, mangrove swamp, bacteria, silver nanoparticles