Conventional airborne virus measurement usually requires appreciable sampling and detection times. Viral aerosols should also be collected or prepared in a liquid medium whose volume typically ranges from milliliters to tens of milliliters; hence, many sampling and detection steps need to be taken with the unit horizontal or immobile. Moreover, viral aerosols need to be sufficiently enriched, which makes real-time monitoring difficult. Herein, we present a near real-time enrichment and quantification system of airborne viruses that consists of a wet-paper-based electrochemical immunosensor with a gel electrolyte and a modified electrostatic particle concentrator. A small amount of phosphate-buffered saline flowed on the electrode, which resulted in sensor electrodes that are barely wet (covered in a thin buffer film measuring several micrometers) to ensure anti-gen-antibody interaction and the removal of non-target particles on the electrode surface. This system ensures that airborne viruses are highly enriched on the working electrode of the immunosensor, and it is possible to measure the MS2 virus particle concentrations every 10 min for 60 min stably and selectively against non-target airborne viruses and bacteria at horizontal and tilted measurement configurations. This system thus has the potential to be used in the real-time mobile monitoring of airborne microorganisms.

Growth tube collectors (GTCs) are used to sample virus aerosols because of their superior viable virus recovery among air samplers. However, a major limitation of such samplers is that they operate at low flow rates compared to many inertia-based air samplers. Herein, we demonstrated efficient measurements of airborne MS2 and T3 viruses using a GTC that can implement high flow velocities for higher flow rates per tube, which we refer to as the growth-based virus aerosol concentrator (GVC), via qPCR and the plaque assay technique. The GVC exhibited a flow rate of up to 6 L/min, where the average sampling flow velocity was 5.09 m/s, 22 times higher than those used in the GTCs, for a single tube with a diameter of 5 mm. The count median diameter of the size-increased particles at the exit of the initiator was measured to be 1.44 µm at 6 L/min, considerably smaller than those observed in conventional GTCs. Nevertheless, the measurement of airborne MS2 and T3 viruses using the GVC showed a high concentration (high enrichment ratio of 109,458 at 10-min sampling) of viruses in a sampling medium, with a high viable virus percentage (> 90%) and physical collection efficiency (> 90%) at 6 L/min, which shows the potential for rapid on-site detection of airborne viruses.

Many studies have been conducted on measuring avian influenza viruses and their hemagglutinin (HA) antigens via electrochemical principles; most of these studies have used gold electrodes on ceramic, glass, or silicon substrates, and/or labeling for signal enhancement. Herein, we present a paper-based immunosensor for label-free measurement of multiple avian influenza virus (H5N1, H7N9, and H9N2) antigens using flexible screen-printed carbon nanotube-polydimethylsiloxane electrodes. These flexible electrodes on a paper substrate can complement the physical weakness of the paper-based sensors when wetted, without affecting flexibility. The relative standard deviation of the peak currents was 1.88% when the electrodes were repeatedly bent and unfolded twenty times with deionized water provided each cycle, showing the stability of the electrodes. For the detection of HA antigens, approximately 10-μl samples (concentration: 100 pg/ml–100 ng/ml) were needed to form the antigen–antibody complexes during 20–30 min incubation, and the immune responses were measured via differential pulse voltammetry. The limits of detections were 55.7 pg/ml (0.95 pM) for H5N1 HA, 99.6 pg/ml (1.69 pM) for H7N9 HA, and 54.0 pg/ml (0.72 pM) for H9N2 HA antigens in phosphate buffered saline, and the sensors showed good selectivity and reproducibility. Such paper-based sensors are economical, flexible, robust, and easy-to-manufacture, with the ability to detect several avian influenza viruses.

Air-transmissible pathogenic viruses, such as influenza viruses and coronaviruses, are some of the most fatal strains and spread rapidly by air, necessitating quick and stable measurements from sample air volumes to prevent further spread of diseases and to take appropriate steps rapidly. Measurements of airborne viruses generally require their collection into liquids or onto solid surfaces, with subsequent hydrosolization and then analysis using the growth method, nucleic-acid-based techniques, or immunoassays. Measurements can also be performed in real time without sampling, where species-specific determination is generally disabled. In this review, we introduce some recent advancements in the measurement of pathogenic airborne viruses. Air sampling and measurement technologies for viral aerosols are reviewed, with special focus on the effects of air sampling on damage to the sampled viruses and their measurements. Measurement of pathogenic airborne viruses is an interdisciplinary research area that requires understanding of both aerosol technology and biotechnology to effectively address the issues. Hence, this review is expected to provide some useful guidelines regarding appropriate air sampling and virus detection methods for particular applications.

Airborne influenza viruses are responsible for serious respiratory diseases, and most detection methods for airborne viruses are based on extraction of nucleic acids. Herein, vertical-flow-assay-based electrochemical paper immunosensors were fabricated to rapidly quantify the influenza H1N1 viruses in air after sampling with a portable electrostatic particle concentrator (EPC). The effects of antibodies, anti-influenza nucleoprotein antibodies (NP-Abs) and anti-influenza hemagglutinin antibodies (HA-Abs), on the paper sensors as well as nonpulsed high electrostatic fields with and without corona charging on the virus measurement were investigated. The antigenicity losses of the surface (HA) proteins were caused by H2O2 via lipid oxidation-derived radicals and 1O2 via direct protein peroxidation upon exposure of a high electrostatic field. However, minimal losses in antigenicity of NP of the influenza viruses were observed, and the concentration of the H1N1 viruses was more than 160 times higher in the EPC than the BioSampler upon using NP-Ab based paper sensors after 60 min collection. This NP-Ab-based paper sensors with the EPC provided measurements comparable to quantitative polymerase chain reaction (qPCR) but much quicker, specific to the influenza H1N1 viruses in the presence of other airborne microorganisms and beads, and more cost-effective than enzyme-linked immunosorbent assay and qPCR.

Acute myocardial infarction (AMI), also recognized as a “heart attack,” is one leading cause of death globally, and cardiac myoglobin (cMb), an important cardiac biomarker, is used for the early assessment of AMI. This paper presents an ultrasensitive, label-free electrochemical aptamer-based sensor (aptasensor) for cMb detection using polyethylenimine (PEI)-functionalized reduced graphene oxide (PEI–rGO) thin films. PEI, a cationic polymer, was used as a reducing agent for graphene oxide (GO), providing highly positive charges on the rGO surface and allowing direct immobilization of negatively charged single-strand DNA aptamers against cMb via electrostatic interaction without any linker or coupling chemistry. The presence of cMb was detected on Mb aptamer-modified electrodes using differential pulse voltammetry via measuring the current change due to the direct electron transfer between the electrodes and cMb proteins (Fe3+/Fe2+). The limits of detection were 0.97 pg mL–1 (phosphate-buffered saline) and 2.1 pg mL–1 (10-fold-diluted human serum), with a linear behavior with logarithmic cMb concentration. The specificity and reproducibility of the aptasensors were also examined. This electrochemical aptasensor using polymer-modified rGO shows potential for the early assessment of cMb in point-of-care testing applications.

Rapid subtyping of influenza viruses in clinical laboratories has been increasingly important because three subtypes (seasonal H1N1, H3N2, and 2009 H1N1) of influenza A virus currently disseminated in humans have variable susceptibilities to antiviral drug. Herein, we present DNA aptamers for selective detection of influenza A H1N1 (seasonal and 2009 pandemic H1N1) viruses by targeting recombinant influenza A mini-hemagglutinin (mini-HA) protein (the stable stem region of HA) and whole H1N1 viruses. The dissociation constants (K-D) of aptamer candidates V46 and V57 were 19.2 nM and 29.6 nM, respectively, according to electrochemical characterization (differential pulse voltammetry), demonstrating strong binding to mini-HA. In comparison, the K-D of the influenza virus antibodies is in the range of 1 mu M-10 nM. Aptamer V46 showed higher specificity and binding affinity to the mini-HA protein and H1N1 subtypes, and it was also incorporated into an indium tin oxide-based electrochemical sensor, showing sensitive and specific detection of H1N1 viruses, with a limit of detection (LOD) of 3.7 plaque-forming units per mL. The binding affinity, specificity, and LOD achieved with the electrochemical sensor suggest that it can be used for rapid subtyping of H1N1. We also propose that this aptamer can be used for the neutralization of H1N1 subtypes, suggesting potential therapeutic and diagnostic applications. (C) 2019 Elsevier B.V. All rights reserved.

We report a method to extract lignin from willow, using triethyl ammonium hydrogen sulphate [Et3NH][HSO4. This method is used to manufacture fibers with a range of compositions.. This extraction achieved an 18% yield of lignin as characterized by ATR-IR and elemental analysis indicated a high carbon yield. 1-Ethyl-3-methylimidazolium acetate [C2C1im][OAc] was then used as a solvent to manufacture lignin-cellulose fiber blends. The Young’s modulus of a 75:25 lignin:cellulose fiber was found to be 3.0 ±0.5 GPa which increased to 5.9 ±0.6 GPa for a 25:75 lignin:cellulose blend. From a characterization of the surface morphology using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) it was observed that a rich lignin content in the fiber blend increased the surface roughness. FT-IR analysis confirmed the presence of aromatic groups of lignin from the presence of peaks located at ~1505 cm and ~1607 cm . The presence of lignin improves the thermal stability of the fiber blends by allowing them degrade over a wider temperature range. This is potentially useful for the utilisation of renewable lignocellulosic biomass derived fibers as carbon fiber precursors. Although the mechanical properties of the regenerated fibers were diminished by the addition of lignin, the blends prepared produced a solution suitablefor a stable fiber spinning process. INTRODUCTION Given concerns over our dependence on petroleum to derive polymeric materials, in the form of fibers and resins, there is a need to develop more sustainable manufacturing routes. Glass fibre processing requires high temperatures in the production process. High performance carbon fibers are predominantly manufactured using non-renewable polyacrylonitrile (PAN) precursors. Lignocellulose biomass-derived regenerated fibers are a promising alternative to replace glass fibers, due to their lower density, and non-renewable PAN based precursors for the production of carbon fibers. Willow is a well-established, historically cultivated crop that shows promise as a source of lignocellulose (lignin, cellulose and hemicellulose) biomass that can be effectively utilised as a renewable resource for making fibers or resins for renewable polymer composite applications. Due to its high carbon content, lignin has been explored as a precursor for making carbon fibers , However the processing of lignin to manufacture carbon fibers is difficult, often requiring chemical modification . To facilitate the spinning of lignin based fibers, researchers have blended the material with synthetic non-renewable polymers such as polypropylene (PP), poly (ethylene oxide) (PEO) and poly(ethylene terephthalate) (PET) . These synthetic polymers are reported to improve the spinnability of lignin by increasing its viscoelastic properties . Cellulose is a potentially sustainable and renewable replacement for synthetic polymers . Cellulose is however known to have a low carbon yield when graphitized. Therefore, there is a potential to blend lignin with cellulose to improve this carbon yield. Blending lignin with cellulose is possible as polar functional groups such as hydroxyl and carbonyl groups allow interaction between the two materials . Ionic liquids (ILs) are solvents purely composed of ions 9. The ability of ILs to dissolve cellulose efficiently relies on the fact that the anion has a high hydrogen bond acceptability . ILs are also known to dissolve other biopolymers, particularly lignin itself, as well as lignocellulose biomass 11, . These developments have opened up opportunities to use ILs as solvents for blending cellulose and lignin to prepare completely sustainable/renewable fibers and as potential precursors for carbon filaments. In this work, fibers with different ratios of lignin (derived from willow) to cellulose were developed using ILs. Lignin-cellulose solutions in ILs are spun into regenerated fibers using a dry-jet wet fiber spinning method. The manufacturing method developed in this study for regenerated-lignin cellulose fibers offers an attractive approach to utilise the willow lignin as a renewable feedstock for composite materials. EXPERIMENTAL METHODS

We present a novel vertical flow-based paper immunosensor for the rapid and sensitive electrochemical and colorimetric detection of influenza H1N1 viruses using a different pore size (DP) sample pad. The DP sample pad consisted of two different pore size papers: larger pores (diameter: 11 µm) facing the inlet, and smaller pores (diameter: 0.45 µm) facing the conjugate pad. This sample pad offered moderate and uniform flows, and hence concentrated horseradish peroxidase tagged antibodies (HRP-Abs)-H1N1 complexes from 40 µL of sample volumes on a conjugate pad for 2 min after sample injection, thereby providing fast detection (6 min for both detection methods) with 100 µL of flushing afterwards, high sensitivity, and the simplicity of the sensor. The filtration characteristics of the DP sample pad were evaluated using fluorescent beads, indicating that only small-sized bio-particles such as viruses can pass through the sample pad. Sandwich immunoreactions of HRP-Ab-H1N1-Ab were performed on the gold paper electrode of the immunoStrip, which was determined by electrochemical impedance spectroscopy (EIS) measurements. Simultaneously, the color signal of free HRP-Ab captured on the colorimetric zone was obtained using a scanner, and the intensity was analyzed using ImageJ. This immunosensor detected H1N1 virus concentration as low as 3.3 plaque forming units (PFU)/mL (phosphate buffer saline; PBS) and 4.7 PFU/mL (saliva) by EIS, and 1.34 PFU/mL (PBS) and 2.27 PFU/mL (saliva) by the colorimetric method. Furthermore, integrating these two detection methods can reduce false results with double assurance, and this device can provide a simple and economical on-site detection platform.

Dielectrophoresis (DEP) is usually effective close to the electrode surface. Several techniques have been developed to overcome its drawbacks and to enhance dielectrophoretic particle capture. Here we present a simple technique of superimposing alternating current DEP (high-frequency signals) and electroosmosis (EO; low-frequency signals) between two coplanar electrodes (gap: 25 μm) using a lab-made voltage adder for rapid and selective concentration of bacteria, viruses, and proteins, where we controlled the voltages and frequencies of DEP and EO separately. This signal superimposition technique enhanced bacterial capture (Escherichia coli K-12 against 1-μm-diameter polystyrene beads) more selectively (>99%) and rapidly (~30 s) at lower DEP (5 Vpp) and EO (1.2 Vpp) potentials than those used in the conventional DEP capture studies. Nanometer-sized MS2 viruses and troponin I antibody proteins were also concentrated using the superimposed signals, and significantly more MS2 and cTnI-Ab were captured using the superimposed signals than the DEP (10 Vpp) or EO (2 Vpp) signals alone (p < 0.035) between the two coplanar electrodes and at a short exposure time (1 min). This technique has several advantages, such as simplicity and low cost of electrode fabrication, rapid and large collection without electrolysis.

We report on the extraction of lignin from willow and its use to manufacture cellulose-lignin fibers as potential precursors for the manufacture of carbon fibers. The lignin from willow was extracted using triethylammonium hydrogen sulfate [Et3NH][HSO4]. The lignin extracted by this process was characterized by ATR-IR and elemental analysis, which indicated a high carbon yield. 1-Ethyl-3-methylimidazolium acetate [C(2)C(1)im][OAc] was then used as a common solvent to dissolve cellulose and lignin to manufacture lignin-cellulose fiber blends. The Young's modulus of a 75:25 lignin/cellulose fiber was found to be 3.0 +/- 0.5 GPa, which increased to 5.9 +/- 0.6 GPa for a 25:75 lignin/cellulose blend. From a characterization of the surface morphology, using scanning electron microscopy (SEM) and atomic force microscopy (AFM), it was observed that higher lignin content in the fiber blend increased the surface roughness. FT-IR analysis confirmed the presence of aromatic groups related to lignin in the obtained fibers from the presence of peaks located at similar to 1 505 cm(-1) and similar to 1607 cm(-1). The presence of lignin improves the thermal stability of the fiber blends by allowing them to degrade over a wider temperature range. The presence of lignin also improved the carbon yield during carbonization. Therefore, the lignin cellulose fibers developed in this work can offer an excellent alternative to pure cellulose or lignin filaments.

We report a novel manufacturing method for bio renewable regenerated cellulose fibres modified with curcumin, a molecule is known for its medicinal properties. Ionic liquid namely 1-Ethyl 3-Methyl Imidazolium diethyl phosphate (emim DEP) was found to be capable of dissolving cellulose as well as curcumin. Regenerated cellulose/curcumin composites fibres with curcumin concentration ranging from 1 to 10 wt% were manufactured using dry jet wet fibres spinning process using three different winding speeds. All the cellulose and curcumin composite fibres showed distinct yellow colour imparted by curcumin. The resultant fibres were characterised using scanning electron microscopy (SEM), infrared spectroscopy, mechanical testing, and X-Ray diffraction studies. Scanning electron microscopy of cellulose/curcumin fibres cross-section did not show curcumin aggregates in cellulose fibres indicating uniform dispersion of curcumin in, cellulose matrix. The cellulose chain alignment in cellulose/curcumin composite fibres resulted in tensile strength ranging from 223 to 336 MPa and Young's modulus ranging from 13 to 14.9 GPa. The mechanical properties of cellulose/curcumin composite fibres thus obtained are better than some of the commercially available regenerated cellulose viscose fibres. The wide-angle X-ray diffraction analysis of cellulose/curcumin composite fibres showed good alignment of cellulose chains along the fibre axis. Thus, our findings are a major step in manufacturing strong cellulose fibres with a pharmacologically potent drug curcumin which in future could be used for medicinal, cosmetic and food packaging applications.

Although many studies concerning the detection of influenza virus have been published, a paper-based, label-free electrochemical immunosensor has never been reported. Here, we present a cost-effective, handmade paper-based immunosensor for label-free electrochemical detection of influenza virus H1N1. This immunosensor was prepared by modifying paper with a spray of hydrophobic silica nanoparticles, and using stencil-printed electrodes. We used a glass vaporizer to spray the hydrophobic silica nanoparticles onto the paper, rendering it super-hydrophobic. The super-hydrophobicity, which is essential for this paper-based biosensor, was achieved via 30–40 spray coatings, corresponding to a 0.39–0.41 mg cm−2 coating of nanoparticles on the paper and yielding a water contact angle of 150° ± 1°. Stencil-printed carbon electrodes modified with single-walled carbon nanotubes and chitosan were employed to increase the sensitivity of the sensor, and the antibodies were immobilized via glutaraldehyde cross-linking. Differential pulse voltammetry was used to assess the sensitivity of the sensors at various virus concentrations, ranging from 10 to 104 PFU mL−1, and the selectivity was assessed against MS2 bacteriophages and the influenza B viruses. These immunosensors showed good linear behaviors, improved detection times (30 min), and selectivity for the H1N1 virus with a limit of detection of 113 PFU mL−1, which is sufficiently sensitive for rapid on-site diagnosis. The simple and inexpensive methodologies developed in this study have great potential to be used for the development of a low-cost and disposable immunosensor for detection of pathogenic microorganisms, especially in developing countries.

The need for low-cost, sensitive, and reliable sensors for the detection of whole bacterial cells in food samples without pre-treatment has been increasing. Outbreaks of foodborne diseases can be severe, especially in developing countries; however, most bio-detection tools are unaffordable. Here, we have developed a rapid and low-cost paper-based electrochemical immunosensor for label-free detection of Staphylococcus aureus, using antibody (Ab)-single walled carbon nanotube (SWCNT) bio-conjugates. Anti-S. aureus antibodies were covalently attached onto the SWCNTs, using the N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide coupling reagent. These Ab-SWCNT bio-conjugates were then immobilized on the working electrode, and the presence of S. aureus was detected by analyzing the change in peak current following antigen-antibody complex formation. Differential pulse voltammetry was performed with a bacterial concentration ranging from 10 to 10(7) colony forming units (CFU) mL(-1). A selectivity assay using Escherichia coli B, Bacillus subtilis, and S. epidermidis (to examine cross-reactivity) showed that the sensor was specific to S. aureus. Moreover, this immunosensor showed a good linear relationship (R-2 = 0.976) between the increase in peak current and logarithmic S. aureus concentration, with a rapid detection time (30 min) and a limit of detection of 13 CFU mL(-1) in spiked milk samples. This low-cost immunosensor can be used for rapid detection of pathogens in actual food samples with high sensitivity and specificity. (C) 2017 Elsevier B.V. All rights reserved.

Strong cellulose fibres and highly ordered carbon fibres can be produced from solutions in superbase ionic liquids.

Measurements of airborne viruses via sampling have been critical issues. Most electrostatic samplers have been assessed for bacterial aerosols or micrometer-sized viral particles; however, sampling of submicrometer-sized airborne viruses is necessary, especially because of the high probability of their staying airborne and their deposition in the lower respiratory tract. Here, we present a novel personal electrostatic particle concentrator (EPC) for gentle sampling of submicrometer airborne virus particles. Owing to the enhanced electric field designed in this EPC, the collection efficiencies reached values as high as 99.3-99.8% for 0.05-2 μm diameter polystyrene particles at a flow rate of 1.2 L/min. Submicrometer-sized MS2 and T3 virus particles were also collected in the EPC, and the concentrations relative to their respective initial suspensions were more than 10 times higher than those in the SKC BioSampler. Moreover, the recovery rate of T3 was 982 times higher in the EPC (-2 kV) than in the BioSampler at 12.5 L/min because of the gentle sampling of the EPC. Gentle sampling is desirable because many bioaerosols suffer from significant viability losses during sampling. The influence of ozone generated, applied electrostatic field, and the flow rate on the viability of the viruses will also be discussed.

Camellia sinensis L. O. Kuntze has traditionally been used in Asian countries as a stimulant, a diuretic, and to prevent obesity. Studies in green tea are well-documented in literature, though the potential of fruit from the plant has never been studied in details. In the present study, the anti-adipogenic effect of aqueous extract of green tea seed cake extract (GTE) were analysed in-vitro and the anti-obesity effects were determined in-vivo in murine model fed high-fat and high-carbohydrate diets. We found that GTE inhibited the lipid accumulation in 3T3-L1 adipocyte and significantly lowered body weight, body fat-pad weights, blood lipid, glucose, insulin, and leptin levels in mice fed high-fat and high-carbohydrate diets. GTE suppressed the expression of important adipogenic genes (PPARγ, C/EBPα, SREBP, LPL, aP2 and leptin) and lipid metabolism genes (FAS). Furthermore, GTE induced the levels of adiponectin in serum and adipose tissue, as well as AMP-activated protein kinase (AMPK) in liver tissue. These results suggested that GTE ameliorates its anti-obesity effect through multiple cells signaling pathways in diets induced obesity in mice.