The here presented work is focused on the development of a method for detection of microbial contamination of food based on uracil-selective synthetic receptors. Because uracil may serve as an indicator of bacterial contamination, its selective and on-site detection may prevent spreading of foodborne diseases. The synthetic receptors were created by molecular imprinting. Molecularly imprinted polymers for selective uracil isolation were prepared by a non-covalent imprinting method using dopamine as a functional monomer. Detection of isolated uracil was performed by capillary electrophoresis with absorption detection (λ - 260 nm). The conditions of preparation of molecularly imprinted polymers, their binding properties, adsorption kinetics and selectivity were investigated in detail. Furthermore, the prepared polymer materials were used for selective isolation and detection of uracil from complex samples as tomato products by miniaturized electrophoretic system suggesting the potential of in situ analysis of real samples.
- MeSH
- adsorpce MeSH
- molekulový imprinting * MeSH
- polymery MeSH
- receptory umělé * MeSH
- uracil MeSH
- Publikační typ
- časopisecké články MeSH
This work characterizes and comparatively assess two cation exchange membranes (PSEBS SU22 and CF22 R14) and one bipolar membrane (FBM) in microbial electrolysis cells (MEC), fed either by acetate or the mixture of volatile fatty acids as substrates. The PSEBS SU22 is a new, patent-pending material, while the CF22 R14 and FBM are developmental and commercialized products. Based on the various MEC performance measures, membranes were ranked by the EXPROM-2 method to reveal which of the polymeric membranes could be more beneficial from a complex, H2 production efficiency viewpoint. It turned out that the substrate-type influenced the application potential of the membranes. Still, in total, the PSEBS SU22 was found competitive with the other alternative materials. The evaluation of MEC was also supported by analyzing anodic biofilms following electroactive bacteria's development over time.
In this work, a novel cation exchange membrane, PSEBS SU22 was deployed in microbial fuel cells (MFCs) to examine system efficacy in line with membrane characteristics and inoculum source. It turned out that compared to a reference membrane (Nafion), employing PSEBS SU22 resulted in higher current density and electricity generation kinetics, while the electron recoveries were similar (19-28%). These outcomes indicated more beneficial ion transfer features and lower mass transfer-related losses in the PSEBS SU22-MFCs, supported by membrane water uptake, ion exchange capacity, ionic conductivity and permselectivity. By re-activating the membranes after (bio)foulant removal, PSEBS SU22 regained nearly its initial conductivity, highlighting a salient functional stability. Although the particular inoculum showed a clear effect on the microbial composition of the membrane biofouling layers, the dominance of aerobic species was revealed in all cases. Considering all the findings, the PSEBS SU22 seems to be promising for application in MFCs.
In this work, two commercialized anion-exchange membranes (AEMs), AMI-7001 and AF49R27, were applied in microbial electrolysis cells (MECs) and compared with a novel AEM (PSEBS CM DBC, functionalized with 1,4-diazabicyclo[2.2.2]octane) to produce biohydrogen. The evaluation regarding the effect of using different AEMs was carried out using simple (acetate) and complex (mixture of acetate, butyrate and propionate to mimic dark fermentation effluent) substrates. The MECs equipped with various AEMs were assessed based on their electrochemical efficiencies, H2 generation capacities and the composition of anodic biofilm communities. pH imbalances, ionic losses and cathodic overpotentials were taken into consideration together with changes to substantial AEM properties (particularly ion-exchange capacity, ionic conductivity, area- and specific resistances) before and after AEMs were applied in the process to describe their potential impact on the behavior of MECs. It was concluded that the MECs which employed the PSEBS CM DBC membrane provided the highest H2 yield and lowest internal losses compared to the two other separators. Therefore, it has the potential to improve MECs.
- MeSH
- anionty chemie MeSH
- design vybavení MeSH
- elektrolýza MeSH
- Geobacter metabolismus MeSH
- kvartérní amoniové sloučeniny chemie MeSH
- membrány umělé * MeSH
- piperaziny chemie MeSH
- studie proveditelnosti MeSH
- vodík metabolismus MeSH
- zdroje bioelektrické energie * mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
In this study, microbial fuel cells (MFCs) - operated with novel cation- and anion-exchange membranes, in particular AN-VPA 60 (CEM) and PSEBS DABCO (AEM) - were assessed comparatively with Nafion proton exchange membrane (PEM). The process characterization involved versatile electrochemical (polarization, electrochemical impedance spectroscopy - EIS, cyclic voltammetry - CV) and biological (microbial structure analysis) methods in order to reveal the influence of membrane-type during start-up. In fact, the use of AEM led to 2-5 times higher energy yields than CEM and PEM and the lowest MFC internal resistance (148 ± 17 Ω) by the end of start-up. Regardless of the membrane-type, Geobacter was dominantly enriched on all anodes. Besides, CV and EIS measurements implied higher anode surface coverage of redox compounds for MFCs and lower membrane resistance with AEM, respectively. As a result, AEM based on PSEBS DABCO could be found as a promising material to substitute Nafion.
Upconversion nanoparticles (UCNPs) are an emerging class of optical materials with high potential in bioimaging due to practically no background signal and high penetration depth. Their excellent optical properties and easy surface functionalization make them perfect for conjugation with targeting ligands. In this work, capillary electrophoretic (CE) method with laser-induced fluorescence detection was used to investigate the behavior of carboxyl-silica-coated UCNPs. Folic acid, targeting folate receptor overexpressed by wide variety of cancer cells, was used for illustrative purposes and assessed by CE under optimized conditions. Peptide-mediated bioconjugation of antibodies to UCNPs was also investigated. Despite the numerous advantages of CE, this is the first time that CE was employed for characterization of UCNPs and their bioconjugates. The separation conditions were optimized including the background electrolyte concentration and pH. The optimized electrolyte was 20 mM borate buffer with pH 8.
- MeSH
- elektroforéza kapilární metody MeSH
- fluorescenční barviva chemie MeSH
- fluorescenční spektrometrie metody MeSH
- kyselina listová chemie MeSH
- limita detekce MeSH
- lineární modely MeSH
- nanokonjugáty chemie MeSH
- protilátky chemie MeSH
- reprodukovatelnost výsledků MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Peptide-peptide interactions are crucial in the living cell as they lead to the formation of the numerous types of complexes. In this study, synthetic peptides containing 11 of cysteines (α-domain of metallothionein (MT)) and sialic acid binding region (130-loop of hemagglutinin (HA)) were employed. The aim of the experiment was studying the interactions between MT and HA-derived peptides. For this purpose, fragments were tagged with cysteines at C-terminal part to serve as ligand sites for PbS and CuS quantum dots (QDs), and therefore these conjugates can be traced and quantified during wide spectrum of methods. As a platform for interaction, γ-Fe2O3 paramagnetic particles modified with tetraethyl orthosilicate and (3-aminopropyl)triethoxysilane (hydrodynamic diameter 30-40 nm) were utilized and MT/HA interactions were examined using multi-instrumental approach including electrochemistry, electrophoretic methods, and MALDI-TOF/TOF mass spectrometry. It was found that peptides enter mutual creation of complexes, which are based on some of nonbonded interactions. The higher willingness to interact was observed in MT-derived peptides toward immobilized HA. Finally, we designed and manufactured flow-through electrochemical 3D printed device (reservoir volume 150 μL) and utilized it for automated analysis of the HA/MT metal labels. Under the optimal conditions, (deposition time and flow rate 80 s and 1.6 mL/min for CuS and 120 s and 1.6 mL/min PbS, respectively), the results of peptide-conjugated QDs were comparable with atomic absorption spectrometry.
Methicillin-resistant Staphylococcus aureus (MRSA) is a dangerous pathogen occurring not only in hospitals but also in foodstuff. Currently, discussions on the issue of the increasing resistance, and timely and rapid diagnostic of resistance strains have become more frequent and sought. Therefore, the aim of this study was to design an effective platform for DNA isolation from different species of microorganisms as well as the amplification of mecA gene that encodes the resistance to β-lactam antibiotic formation and is contained in MRSA. For this purpose, we fabricated 3D-printed chip that was suitable for bacterial cultivation, DNA isolation, PCR, and detection of amplified gene using gold nanoparticle (AuNP) probes as an indicator of MRSA. Confirmation of the MRSA presence in the samples was based on a specific interaction between mecA gene with the AuNP probes and a colorimetric detection, which utilized the noncross-linking aggregation phenomenon of DNA-functionalized AuNPs. To test the whole system, we analyzed several real refractive indexes, in which two of them were positively scanned to find the presence of mecA gene. The aggregation of AuNP probes were reflected by 75% decrease of absorbance (λ = 530 nm) and change in AuNPs size from 3 ± 0.05 to 4 ± 0.05 nm (n = 5). We provide the one-step identification of mecA gene using the unique platform that employs the rapid, low-cost, and easy-to-use colorimetric method for MRSA detection in various samples.
- MeSH
- absces mikrobiologie MeSH
- bakteriální proteiny genetika MeSH
- design vybavení MeSH
- DNA bakterií analýza genetika MeSH
- kovové nanočástice chemie MeSH
- lidé středního věku MeSH
- lidé MeSH
- methicilin rezistentní Staphylococcus aureus genetika izolace a purifikace MeSH
- molekulární typizace MeSH
- sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů přístrojové vybavení metody MeSH
- stafylokokové infekce mikrobiologie MeSH
- techniky amplifikace nukleových kyselin MeSH
- zlato chemie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Using of 3D printing technology (acrylonitrile butadiene styrene as material) stratospheric probe (SP) was developed for the purpose of this experiment. Fluorescent behavior of carbon quantum dots (CQDs) in concentration range 0-32 mg.ml-1 was monitored by stratospheric probe and classical fluorescence spectroscopy. Balloon flight lasted 120 minutes. During this time it traveled 90 km. At a height of approximately 40 km there was a rupture of balloon. Thanks to a parachute SP landed in a controlled manner in the wood in the cadastral area of municipality Brusnica (Slovak Republic). It was found that the fluorescence intensity of CQDs changed slightly before and after the flight, however this was caused by the CQDs instability and not by the detector design.
- MeSH
- 3D tisk MeSH
- atmosféra * MeSH
- design vybavení MeSH
- fluorescence * MeSH
- kvantové tečky * MeSH
- uhlík MeSH
- Publikační typ
- hodnotící studie MeSH
- práce podpořená grantem MeSH
This study presents synthesis of paramagnetic particles formed by nanomaghemite (γ-Fe2O3) core, whose surface was modified with LaCl3 and entire composite is able to specifically bind the bacteriophage λ. In this study we described the structure of bacteriophage λ, its biochemical properties and role in the therapy, biotechnology and nanomedicine. In the next part we summarized accessible information about paramagnetic particles, their attributes and specificity of binding the bacteriophage λ. Paramagnetic particles show the ability to immobilize bacteriophage λ for subsequent analysis using ion-exchange chromatography with Vis detection. The presence of bacteriophage λ on the surface of paramagnetic beads was demonstrated by sodium dodecyl sulphate gel electrophoresis (SDS-PAGE). It can be stated that paramagnetic beads show significant binding ability towards bacteriophage λ. This phenomenon can be employed for magnetic separation of bacteriophages prior their possible modifications and subsequent application as a cytostatic nanotransporters or antimicrobial agents usable in hard-to-heal bacterial infections.
- Klíčová slova
- superparamagnetic iron oxide nanoparticles,
- MeSH
- bakteriofág lambda * chemie MeSH
- bakteriofágy MeSH
- chromatografie iontoměničová MeSH
- elektroforéza v polyakrylamidovém gelu MeSH
- magnetické nanočástice * MeSH
- nanomedicína MeSH
- nanotechnologie MeSH
- oxidy MeSH
- železnaté sloučeniny MeSH
- železo MeSH
- Publikační typ
- práce podpořená grantem MeSH
