Development of Photonic Multi-Sensing Systems Based on Molecular Gates Biorecognition and Plasmonic Sensors: The PHOTONGATE Project.

This paper presents the concept of a novel adaptable sensing solution currently being developed under the EU Commission-founded PHOTONGATE project. This concept will allow for the quantification of multiple analytes of the same or different nature (chemicals, metals, bacteria, etc.) in a single test with levels of sensitivity and selectivity at/or over those offered by current solutions. PHOTONGATE relies on two core technologies: a biochemical technology (molecular gates), which will confer the specificity and, therefore, the capability to be adaptable to the analyte of interest, and which, combined with porous substrates, will increase the sensitivity, and a photonic technology based on localized surface plasmonic resonance (LSPR) structures that serve as transducers for light interaction. Both technologies are in the micron range, facilitating the integration of multiple sensors within a small area (mm2). The concept will be developed for its application in health diagnosis and food safety sectors. It is thought of as an easy-to-use modular concept, which will consist of the sensing module, mainly of a microfluidics cartridge that will house the photonic sensor, and a platform for fluidic handling, optical interrogation, and signal processing. The platform will include a new optical concept, which is fully European Union Made, avoiding optical fibers and expensive optical components.

Improving Structural Homogeneity, Hydraulic Permeability, and Mechanical Performance of Asymmetric Monophasic Cellulose Acetate/Silica Membranes: Spinodal Decomposition Mix.

In this paper, we propose an optimized protocol to synthesize reproducible, accurate, sustainable integrally skinned monophasic hybrid cellulose acetate/silica membranes for ultrafiltration. Eight different membrane compositions were studied, divided into two series, one and two, each composed of four membranes. The amount of silica increased from 0 wt.% up to 30 wt.% (with increments of 10 wt.%) in each series, while the solvent composition was kept constant within each series (formamide/acetone ratio equals 0.57 wt.% in series one and 0.73 wt.% in series two). The morphology of the membranes was analyzed by scanning electron microscopy and the chemical composition by Fourier transform infrared spectroscopy, in attenuated total reflection mode (FTIR-ATR). Mechanical tensile properties were determined using tensile tests, and a retest trial was performed to assess mechanical properties variability over different membrane batches. The hydraulic permeability of the membranes was evaluated by measuring pure water fluxes following membrane compaction. The membranes in series two produced with a higher formamide/acetone solvent ratio led to thicker membranes with higher hydraulic permeability values (47.2-26.39 kg·h-1·m-2·bar-1) than for the membranes in series one (40.01-19.4 kg·h-1·m-2·bar-1). Results obtained from the FTIR-ATR spectra suggest the presence of micro/nano-silica clusters in the hybrid membranes of series one, also exhibiting higher Young's modulus values than the hybrid membranes in series two.

Interaction of Human Serum Albumin with Uremic Toxins: The Need of New Strategies Aiming at Uremic Toxins Removal.

Chronic kidney disease (CKD) is acknowledged worldwide to be a grave threat to public health, with the number of US end-stage kidney disease (ESKD) patients increasing steeply from 10,000 in 1973 to 703,243 in 2015. Protein-bound uremic toxins (PBUTs) are excreted by renal tubular secretion in healthy humans, but hardly removed by traditional haemodialysis (HD) in ESKD patients. The accumulation of these toxins is a major contributor to these sufferers' morbidity and mortality. As a result, some improvements to dialytic removal have been proposed, each with their own upsides and drawbacks. Longer dialysis sessions and hemodiafiltration, though, have not performed especially well, while larger dialyzers, coupled with a higher dialysate flow, proved to have some efficiency in indoxyl sulfate (IS) clearance, but with reduced impact on patients' quality of life. More efficient in removing PBUTs was fractionated plasma separation and adsorption, but the risk of occlusive thrombosis was worryingly high. A promising technique for the removal of PBUTs is binding competition, which holds great hopes for future HD. This short review starts by presenting the PBUTs chemistry with emphasis on the chemical interactions with the transport protein, human serum albumin (HSA). Recent membrane-based strategies targeting PBUTs removal are also presented, and their efficiency is discussed.

Ultrasound assisted extraction of phenolic acids from broccoli vegetable and using sonochemistry for preparation of MOF-5 nanocubes: Comparative study based on micro-dilution broth and plate count method for synergism antibacterial effect.

The aim of this work was comparison study of dilution and plating method for evaluation of the synergism effect of metal-organic framework nanocubes (MOF-5-NCs) and broccoli extract (Brassica oleracea) on antibacterial activity of standard and clinical Pseudomonas aeruginosa strains. For this purpose, sonochemical synthesis of MOF-5-NCs was performed and it was characterized using XRD, FT-IR, FESEM and EDS techniques. Maceration extraction (ME) and ultrasound assisted extraction (UAE) methods in three different solvents were prepared and applicability of their extracts were compared in some cases such as radical scavenging and antioxidant activity. The HPLC/UV analysis was applied for separation, identification and evaluation of phenolic acids in prepared broccoli extracts. Then, antimicrobial activity of MOF-5NCs and broccoli extract against gram-negative bacteria, Pseudomonas aeruginosa was evaluated by detection of minimal inhibition concentration (MIC), minimal bactericidal concentration (MBC) and zone of inhibition (ZOI). The results of in vitro assays showed that dilution method due to flase estimation of 4% viability percentage which is not logic by consideration of MBC well could not be able to estimate MBC. Therefore, plate count method was performed for precise calculation of MBC. MIC of broccoli extract and MOF-5-NCs on Pseudomonas aeruginosa strains were 7.81mgmL-1 and 3.13mgmL-1, respectively.

Comparison between dispersive solid-phase and dispersive liquid-liquid microextraction combined with spectrophotometric determination of malachite green in water samples based on ultrasound-assisted and preconcentration under multi-variable experimental design optimization.

The ultrasound-assisted dispersive solid-phase microextraction (USA-DSPME) and the ultrasound-assisted dispersive liquid-liquid microextraction (USA-DLLME) developed for as an ultra preconcentration and/or technique for the determination of malachite green (MG) in water samples. Central composite design based on analysis of variance and desirability function guide finding best operational conditions and represent dependency of response to variables viz. volume of extraction, eluent and disperser solvent, pH, adsorbent mass and ultrasonication time has significant influence on methods efficiency. Optimum conditions was set for USA-DSPME as: 1mg CNTs/Zn:ZnO@Ni2P-NCs; 4min sonication time and 130µL eluent at pH 6.0. Meanwhile optimum point for USA-DLLME conditions were fixed at pH 6.0; 4min sonication time and 130, 650µL and 10mL of extraction solvent (CHCl3), disperser solvent (ethanol) and sample volume, respectively. Under the above specified best operational conditions, the enrichment factors for the USA-DSPME and USA-DLLME were 88.89 and 147.30, respectively. The methods has linear response in the range of 20.0 to 4000.0ngmL-1 with the correlation coefficients (r) between 0.9980 to 0.9995, while its reasonable detection limits viz. 1.386 to 2.348ngmL-1 and good relative standard deviations varied from 1.1% to 2.8% (n=10) candidate this method for successful monitoring of analyte from various media. The relative recoveries of the MG dye from water samples at spiking level of 500ngmL-1 were in the range between 94.50% and 98.86%. The proposed methods has been successfully applied to the analysis of the MG dye in water samples, and a satisfactory result was obtained.

Multi-response optimization of ultrasound assisted competitive adsorption of dyes onto Cu (OH)2-nanoparticle loaded activated carbon: Central composite design.

This paper focuses on the development of an effective methodology to obtain the optimum removal conditions assisted by ultrasonics to maximize the simultaneous removal of dyes, eosin Y (EY), methylene blue (MB) and phenol red (PR), by Cu(OH)2-NP-AC in aqueous solution using response surface methodology (RSM). The effects of variables such as pH, initial dyes concentrations (mgL-1), and amount of sorbent (mg) and sonication time (min) on the dyes removal were studied. A central composite design (CCD) was applied to evaluate the interactive effects of adsorption variables. A good correlation (with R2>0.940) between the statistical model and experiment was found for dyes removal from aqueous wastewater using the adsorbent. The optimum removal (99.20%±1.48) was thus obtained at pH 6.0, ultrasound time 2.5min, adsorbent mass 20mg and initial dye concentration at 5mgL-1 for MB and EY and 12.5mgL-1 for PR. The maximum adsorption capacity (Qmax) was calculated from the Langmuir isotherm as 32.9, 26.4 and 38.5mgg-1 for the MB, EY and PR, respectively for the 0.015g of sorbent. The adsorption kinetic data of the dyes were analyzed and was found fitting well in a pseudo-second-order equation. Adsorption isotherms and separation factors showed that the adsorbent displays a high selectivity toward one dye in a three-component system with an affinity order of PR>MB>EY. On the other hand, acoustic waves emitted by the cavitation bubbles render a direct effect on the process. This is attributed to the discrete nature and high pressure amplitude of the waves, which creates excessively high convection in the medium, causing adsorption of the pollutants. The chemical nature of the pollutants influences the enhancement effect of ultrasound.

Dispersion of hydrophobic magnetic nanoparticles using ultarsonic-assisted in combination with coacervative microextraction for the simultaneous preconcentration and determination of tricyclic antidepressant drugs in biological fluids.

A two-step sample preparation technique based on dispersive micro solid-phase extraction combined with coacervative microextraction is presented for preconcentration and determination of tricyclic antidepressant drugs in biological samples. An important feature of the method is the application of hydrophobic magnetic nanoparticles, which in combination with coacervative microextraction method enables development of rapid and efficient extraction procedure in order to achievement of a high extraction efficiency. Simultaneous optimization by experimental design lead to improvement of method with low cost which supply useful information about interaction among variables. Under the optimized conditions, a linear range of 5-1000ngmL(-1) with detection limits from 0.51 to 1.4ngmL(-1) were obtained for target analytes. The method was successfully used for the determination of analytes in biological fluids (plasma and urine) with relative recoveries in the range of 89-105% (RSDs<3.5%).

Magnetic molecularly imprinted polymer for the efficient and selective preconcentration of diazinon before its determination by high-performance liquid chromatography.

A molecularly imprinted polymer was selectively applied for solid-phase extraction and diazinon residues enrichment before high-performance liquid chromatography. Diazinon was thermally copolymerized with Fe3 O4 @polyethyleneglycol nanoparticles, methacrylic acid (functional monomer), 2-hydroxyethyl methacrylate (co-monomer), and ethylene glycol dimethacrylate (cross-linking monomer) in the presence of acetonitrile (porogen) and 2,2-azobisisobutyronitrile (initiator). Then, the imprinted diazinon was reproducibly eluted with methanol/acetic acid (9:1, v/v). The sorbent particles were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The comprehensive study of variables through experimental design showed that the maximum performance was achieved under these conditions: pH 7, 10 mL sample volume, 15 mg sorbent, 10 min vortex time, 5 min ultrasonic time, 200 µL methanol/acetic acid (9:1, v/v) as eluent, and 5 min desorption time. Under optimized conditions, the molecularly imprinted polymer solid-phase extraction method demonstrated a linear range (0.02-5 g/mL), a correlation coefficient of 0.997, and 0.005 g/mL detection limit.

Ionic-liquid-based surfactant-emulsified microextraction procedure accelerated by ultrasound radiation followed by high-performance liquid chromatography for the simultaneous determination of antidepressant and antipsychotic drugs.

In the present work, an efficient and environmental friendly method of ionic-liquid-based emulsified microextraction procedure accelerated by ultrasound radiation has been developed. Subsequently, its performance was compared with dispersive liquid-liquid microextraction and ultrasound-assisted surfactant-based emulsification microextraction methods. The optimization of experimental conditions was carried out by combination of central composite design and response surface methodology. The optimum conditions of variables were set as follows: 50 µL of 1-hexyl-3-methylimidazolium hexafluorophosphate (extracting solvent), 10 min ultrasound time, and 10 min vortex time for agitating 6 mL sample solution in pH 3 in the presence of 4 mg sodium dodecyl sulfate without addition of salt and 200 µL of methanol as diluent solvent. Under these conditions, the responses are linear for doxepin and perphenazine in the range of 0.3-1000 and 5-1000 µg/L, respectively. The limits of detection were 0.1 µg/L for doxepin and 1 µg/L for perphenazine. Relative standard deviations were lower than 3.5 for the determination of both species. Finally, the method was used for the preconcentration and determination of doxepin and perphenazine in urine sample with relative recoveries in the range of 89-98%.