MAGNETICALLY RESPONSIVE MATERIALS FOR SOLID PHASE EXTRACTION

Magnetically responsive materials have found many important applications in analytical chemistry. In this short review the basic information about Magnetic solid phase extraction and Magnetic textile solid phase extraction is given. These analytical techniques enable to preconcentrate target biologically active compounds or pollutants from water samples. Both procedures enable to lower the limit of detection using conventional analytical procedures

Miniaturized analytical methods for determination of environmental contaminants of emerging concern - a review

The determination of contaminants of emerging concern (CECs) in environmental samples has become a challenging and critical issue. The present work focuses on miniaturized analytical strategies reported in the literature for the determination of CECs. The first part of the review provides brief overview of CECs whose monitoring in environmental samples is of particular significance, namely personal care products, pharmaceuticals, endocrine disruptors, UV-filters, newly registered pesticides, illicit drugs, disinfection by-products, surfactants, high technology rare earth elements, and engineered nanomaterials. Besides, an overview of downsized sample preparation approaches reported in the literature for the determination of CECs in environmental samples is provided. Particularly, analytical methodologies involving microextraction approaches used for the enrichment of CECs are discussed. Both solid phase- and liquid phase-based microextraction techniques are highlighted devoting special attention to recently reported approaches. Special emphasis is placed on newly developed materials used for extraction purposes in microextraction techniques. In addition, recent contributions involving miniaturized analytical flow techniques for the determination of CECs are discussed. Besides, the strengths, weaknesses, opportunities and threats of point of need and portable devices have been identified and critically compared with chromatographic methods coupled to mass chromatography. Finally, challenging aspects regarding miniaturized analytical methods for determination of CECs are critically discussed

Decrease of Pseudomonas aeruginosa biofilm formation by food waste materials

The formation of bacterial biofilm on various surfaces has significant negative economic effects. The aim of this study was to find a simple procedure to decrease the Pseudomonas aeruginosa biofilm formation in a water environment by using different food waste biological materials as signal molecule adsorbents. The selected biomaterials did not reduce the cell growth but affected biofilm formation. Promising biomaterials were magnetically modified in order to simplify manipulation and facilitate their magnetic separation. The best biocomposite, magnetically modified spent grain, exhibited substantial adsorption of signal molecules and decreased the biofilm formation. These results suggest that selected food waste materials and their magnetically responsive derivatives could be applied to solve biofilm problems in water environment.N

Composite particles formed by complexation of poly(methacrylic acid) — stabilized magnetic fluid with chitosan: Magnetic material for bioapplications

A simple procedure for the synthesis of magnetic fluid (ferrofluid) stabilized by poly(methacrylic acid) has been developed. This ferrofluid was used to prepare a novel type of magnetically responsive chitosan-based composite material. Both ferrofluid and magnetic chitosan composite were characterized by a combination of microscopy (optical microscopy, TEM, SEM), scattering (static and dynamic light scattering, SANS) and spectroscopy (FTIR) techniques. Magnetic chitosan was found to be a perspective material for various bioapplications, especially as a magnetic carrier for immobilization of enzymes and cells. Lipase from Candida rugosa was covalently attached after cross-linking and activation of chitosan using glutaraldehyde. Baker's yeast cells (Saccharomyces cerevisiae) were incorporated into the chitosan composite during its preparation; both biocatalysts were active after reaction with appropriate substrates

Magnetization of active inclusion bodies: comparison with centrifugation in repetitive biotransformations

Abstract Background Physiological aggregation of a recombinant enzyme into enzymatically active inclusion bodies could be an excellent strategy to obtain immobilized enzymes for industrial biotransformation processes. However, it is not convenient to recycle “gelatinous masses” of protein inclusion bodies from one reaction cycle to another, as high centrifugation forces are needed in large volumes. The magnetization of inclusion bodies is a smart solution for large-scale applications, enabling an easier separation process using a magnetic field. Results Magnetically modified inclusion bodies of UDP–glucose pyrophosphorylase were recycled 50 times, in comparison, inclusion bodies of the same enzyme were inactivated during ten reaction cycles if they were recycled by centrifugation. Inclusion bodies of sialic acid aldolase also showed good performance and operational stability after the magnetization procedure. Conclusions It is demonstrated here that inclusion bodies can be easily magnetically modified by magnetic iron oxide particles prepared by microwave-assisted synthesis from ferrous sulphate. The magnetic particles stabilize the repetitive use of the inclusion bodies

Cotton Textile/Iron Oxide Nanozyme Composites with Peroxidase-like Activity: Preparation, Characterization, and Application

At present, both native and immobilized nanoparticlesare of great importance in many areas of science andtechnology. In this paper, we have studied magnetic iron oxidenanoparticles and their aggregates bound on woven cotton textilesemploying two simple modification procedures. One modificationwas based on the treatment of textiles with perchloric-acidstabilizedmagnetic fluid diluted with methanol followed by drying.The second procedure was based on the microwave-assistedconversion of ferrous sulfate at high pH followed by drying. Thestructure and functional properties of these modified textiles wereanalyzed in detail. Scanning electron microscopy of native and modified textiles clearly showed the presence of iron oxidenanoparticles on the surface of the modified cotton fibers. All of the modified textile materials exhibited light to dark brown colordepending on the amount of the bound iron oxide particles. Magnetic measurements showed that the saturation magnetizationvalues reflect the amount of magnetic nanoparticles present in the modified textiles. Small-angle X-ray and neutron scatteringmeasurements were conducted for the detailed structural characterization at the nanoscale of both the native and magneticallymodified textiles, and different structural organization of nanoparticles in the two kinds of textile samples were concluded. Thetextile-bound iron oxide particles exhibited peroxidase-like activity when the N,N-diethyl-p-phenylenediamine sulfate salt was used asa substrate; this nanozyme activity enabled rapid decolorization of crystal violet in the presence of hydrogen peroxide. Thedeposition of a sufficient amount of iron oxide particles on textiles enabled their simple magnetic separation from large volumes ofsolutions; if necessary, the magnetic response of the modified textiles can be simply increased by incorporation of a piece of magneticiron wire. The simplicity of the immobilized nanozyme preparation and the low cost of all the precursors enable its widespreadapplication, such as decolorization and degradation of selected organic dyes and other important pollutants. Other types of textileboundnanozymes can be prepared and used as low-cost catalysts for a variety of applications

Miniaturized analytical methods for determination of environmental contaminants of emerging concern – A review

The determination of contaminants of emerging concern (CECs) in environmental samples has become a challenging and critical issue. The present work focuses on miniaturized analytical strategies reported in the literature for the determination of CECs. The first part of the review provides brief overview of CECs whose monitoring in environmental samples is of particular significance, namely personal care products, pharmaceuticals, endocrine disruptors, UV-filters, newly registered pesticides, illicit drugs, disinfection by-products, surfactants, high technology rare earth elements, and engineered nanomaterials. Besides, an overview of downsized sample preparation approaches reported in the literature for the determination of CECs in environmental samples is provided. Particularly, analytical methodologies involving microextraction approaches used for the enrichment of CECs are discussed. Both solid phase- and liquid phase-based microextraction techniques are highlighted devoting special attention to recently reported approaches. Special emphasis is placed on newly developed materials used for extraction purposes in microextraction techniques. In addition, recent contributions involving miniaturized analytical flow techniques for the determination of CECs are discussed. Besides, the strengths, weaknesses, opportunities and threats of point of need and portable devices have been identified and critically compared with chromatographic methods coupled to mass chromatography. Finally, challenging aspects regarding miniaturized analytical methods for determination of CECs are critically discussed.European Cooperation in Science and Technology (COST) | Ref. CA 16215Ministerio de Ciencia, Innovación y Universidades | Ref. RTI2018-093697-B-I00UK NERC | Ref. NE / R013349 / 2Fundação para a Ciência e a Tecnologia | Ref. UIDB / 50006/202