In this work we discuss a new label-free biosensing device based on indium tin oxide (ITO) overlaid section of a multimode optical fiber fused silica core. The sensor has been used to optical measurements also simultaneously interrogated electrochemically (EC). Due to optimized thickness and optical properties of ITO film, a lossy-mode resonance (LMR) could be observed in the optical domain, where electrical properties of the film allowed for application of the sensor as a working electrode in an EC setup. It has been confirmed that the LMR response depends on optical properties of the external medium, as well as potential applied to the electrode during cyclic voltammetry. After the ITO surface functionalization with amine groups and covalently attached biotin, the device has been applied for label-free biosensing of avidin in both the domains simultaneously. On the example of biotin-avidin detection system it was demonstrated that when avidin concentration increases a decrease in current and increase in LMR wavelength shift were recorded in EC and optical domain, respectively. Both optical and EC responses follow the protein interaction process, and thus can be used as cross-verification of the readouts. Moreover, an extended information has been achieved comparing to solely EC interrogation, i.e., the grafting process of biotin and avidin was directly monitored optically displaying individual steps of an incubation procedure.
Custom immuno-magnetic devices are desirable tools for biomedical and biotechnological applications. Herein, surface active maghemite nanoparticles (SAMNs) are proposed as a versatile platform for developing tailored immuno-magnetic nano-carriers by simple wet reactions. Two examples for conjugating native and biotinylated antibodies were presented along with their successful applications in the recognition of specific foodborne pathogens. Nanoparticles were functionalized with rhodamine B isothiocyanate (RITC), leading to a fluorescent nano-conjugate, and used for binding anti-Campylobacter fetus antibodies (SAMN@RITC@Anti-Cf). The microorganism was selectively captured in the presence of two other Campylobacter species (C. jejuni and C. coli), as verified by PCR. Alternatively, SAMNs were modified with avidin, forming a biotin-specific magnetic nano-carrier and used for the immobilization of biotinylated anti-Listeria monocytogenes antibodies (SAMN@avidin@Anti-Lm). This immuno-magnetic carrier was integrated in piezoelectric quartz crystal microbalance (QCM) sensor for the detection of L. monocytogenes in milk, showing a detection limit of 3 bacterial cells. The present work presents a new category of customized immuno-magnetic nano-carriers as a competitive option for suiting specific applications. Graphical abstract ᅟ.
- MeSH
- adjuvancia imunologická chemie MeSH
- avidin chemie MeSH
- Listeria imunologie MeSH
- magnetismus * MeSH
- mikrorovnovážné techniky křemenného krystalu metody MeSH
- monoklonální protilátky chemie MeSH
- nanočástice chemie MeSH
- povrchové vlastnosti MeSH
- transmisní elektronová mikroskopie MeSH
- železité sloučeniny chemie MeSH
- Publikační typ
- časopisecké články MeSH
Avidin-biotin technology was used for the implementation of an enzyme-linked immunosorbent assay (AB-ELISA) as a sensitive method for the detection of anabolic androgenic steroids (AAS) present in dietary supplements. Using click chemistry, novel haptens (linker-optimized biotinylated nandrolone (NT) and testosterone (T) at positions C-3 and C-17, respectively) were designed and synthesized to be then applied as four different immobilized competitors in a proposed set of four indirect competitive AB-ELISAs. Four rabbit polyclonal antibodies of various specificities were prepared using four different immunogens synthesized from C-3 and C-17 carboxymethyloxime and hemisuccinate derivatives of NT and T, respectively. Assembled AB-ELISAs were characterized to establish method parameters such as a half-maximum inhibition concentration (0.18-12.99 ng/mL), limit of detection (0.004-0.032 ng/mL) and linear working range (the best with 0.02-1.38 ng/mL). The stability of the set simulating storage in different conditions was demonstrated. Cross reactivity (CR) was tested for 59 steroids including both endogenous and synthetic analogues in four assembled AB-systems. The focus was placed on the practical use of the method in detection of various AAS in 49 samples of counterfeit dietary supplements. The concordance between ultra high performance liquid chromatography-mass spectrometry (UHPLC-MS) and the CR corrected data from AB-ELISA indicated the potential of this method even to quantification of T propionate, NT phenyl propionate, and NT decanoate in such a complex matter. Copyright © 2016 John Wiley & Sons, Ltd.
- MeSH
- anabolika analýza MeSH
- avidin chemie MeSH
- biotin chemie MeSH
- ELISA metody MeSH
- králíci MeSH
- limita detekce MeSH
- nandrolon analýza MeSH
- potravní doplňky analýza MeSH
- testosteron analýza MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- MeSH
- avidin diagnostické užití MeSH
- biosenzitivní techniky metody přístrojové vybavení využití MeSH
- biotin diagnostické užití MeSH
- bromkyan diagnostické užití MeSH
- epichlorhydrin diagnostické užití MeSH
- glutaraldehyd diagnostické užití MeSH
- karbodiimidy diagnostické užití MeSH
- klinické laboratorní techniky trendy využití MeSH
- kyselina jodistá diagnostické užití MeSH
- makromolekulární látky izolace a purifikace MeSH
- merkaptamin diagnostické užití MeSH
- nanočástice diagnostické užití MeSH
- polysacharidy diagnostické užití MeSH
- streptavidin diagnostické užití MeSH
- sukcinimidy diagnostické užití MeSH
Angiosarkom velkých slinných žláz patří ke vzácně se vyskytujícím nádorům. Autoři uvádějí jeden takový nádor lokalizovaný v pravé příušní žláze 77leté ženy. Histologické vyšetření ukázalo, že šlo o nediferencovaný nádor tvořený epiteloidními strukturami a protáhlými nádorovými buňkami. Oba buněčné typy v sebe vzájemně přecházejí. Místy byly zjištěny i primitivní, vzájemně anastomozující nepravidelné cévní prostory s atypickými endoteliemi. Nádor pozitivně reagoval s protilátkami proti CD31, CD34, EMA a FVIII (ložiskovitě) antigenům. K prognóze onemocnění je zatím obtížné se vyslovit vzhledem ke klinicky relativně krátké době sledování pacientky.
Angiosarcomas of the major salivary glands are rare tumours. The authors describe a case of the tumour located in the right parotid gland of a 77-year-old woman. Histological examination revealed a poorly differentiated tumour made up of epithelioid and spindle cells. These two types of cells intermingled. In some parts, primitive mutually anastomosing irregularly shaped vascular spaces with atypical endothelial cells were found. The tumour cells were positive for CD31, CD34, EMA and FVIII (focally). Due to the relatively short follow-up period the prognosis of the disease is difficult to estimate.
- MeSH
- avidin diagnostické užití MeSH
- biotin diagnostické užití MeSH
- chirurgie operační metody využití MeSH
- diferenciální diagnóza MeSH
- imunohistochemie metody využití MeSH
- lidé MeSH
- mikroskopie metody využití MeSH
- nádory příušní žlázy diagnóza etiologie terapie MeSH
- nádory slinných žláz diagnóza etiologie terapie MeSH
- nádory z cévní tkáně diagnóza terapie MeSH
- radioterapie metody využití MeSH
- senioři MeSH
- Check Tag
- lidé MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
This paper presents a synthesis of a novel nanoparticle label with selective biorecognition properties based on a biotinylated silver-dendrimer nanocomposite (AgDNC). Two types of labels, a biotin-AgDNC (bio-AgDNC) and a biotinylated AgDNC with a poly(ethylene)glycol spacer (bio-PEG-AgDNC), were synthesized from a generation 7 (G7) hydroxyl-terminated ethylenediamine-core-type (2-carbon core) PAMAM dendrimer (DDM) by an N,N'-dicyclohexylcarbodiimide (DDC) biotin coupling and a NaBH(4) silver reduction method. Synthesized conjugates were characterized by several analytical methods, such as UV-vis, FTIR, AFM, TEM, ELISA, HABA assay and SPR. The results show that stable biotinylated nanocomposites can be formed either with internalized silver nanoparticles (AgNPs) in a DMM polymer backbone ('type I') or as externally protected ('type E'), depending on the molar ratio of the silver/DMM conjugate and type of conjugate. Furthermore, the selective biorecognition function of the biotin is not affected by the AgNPs' synthesis step, which allows a potential application of silver nanocomposite conjugates as biospecific labels in various bioanalytical assays, or potentially as fluorescence cell biomarkers. An exploitation of the presented label in the development of electrochemical immunosensors is anticipated.
- MeSH
- avidin metabolismus MeSH
- barvení a značení metody MeSH
- biotin chemie metabolismus MeSH
- dendrimery MeSH
- ELISA MeSH
- kinetika MeSH
- mikroskopie atomárních sil MeSH
- molekulární modely MeSH
- nanokompozity chemie MeSH
- polyaminy chemická syntéza chemie MeSH
- povrchová plasmonová rezonance MeSH
- spektrofotometrie ultrafialová MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- stříbro chemie MeSH
- transmisní elektronová mikroskopie MeSH
- Publikační typ
- práce podpořená grantem MeSH
A complex of osmium tetroxide with 2,2'-bipyridine (Os,bipy) has been applied as a chemical probe of DNA structure as well as an electroactive DNA label. The Os,bipy has been known to form covalent adducts with pyrimidine DNA bases. Besides the pyrimidines, electrochemically active covalent adducts with Os,bipy are formed also by tryptophan (W) residues in peptides and proteins. In this paper we show that Os,bipy-treated proteins possessing W residues (such as avidin, streptavidin, or lysozyme) yield at the pyrolytic graphite electrode (PGE) a specific signal (peak alphaW) the potential of which differs from the potentials of signals produced by free Os,bipy or by Os,bipy-modified DNA. No such signal is observed with proteins lacking W (such as ribonuclease A or alpha-synuclein). Subpicomole amounts of W-containing proteins modified with Os,bipy can easily be detected using adsorptive transfer stripping voltammetry with the PGE. Binding of biotin to avidin interferes with Os,bipy modification of the protein, in agreement with the location of W residues within the biotin-binding site of avidin. These Ws are accessible for modification in the absence of biotin but hidden (protected from modification) in the avidin-biotin complex. The Os,bipy-modified avidin is unable to bind biotin, and its quarternary structure is disrupted. Analogous effects were observed with another biotin-binding protein, streptavidin. Our results demonstrate that modification of proteins with Os,bipy under conditions close to physiological, followed by a simple electrochemical analysis, can be applied in the microanalysis of protein structure and interactions.
- MeSH
- 2,2'-dipyridyl chemie MeSH
- avidin chemie MeSH
- biotin chemie MeSH
- elektrochemie MeSH
- elektrody MeSH
- elektrony MeSH
- financování organizované MeSH
- molekulární struktura MeSH
- oxid osmičelý analýza chemie MeSH
- proteiny analýza chemie MeSH
- reagencia zkříženě vázaná chemie MeSH
- tryptofan analýza chemie MeSH
- uhlík chemie MeSH
Four series of macroporous hydrogels based on crosslinked copolymers of 2-hydroxyethyl methacrylate (HEMA)-sodium methacrylate (MANa), copolymer HEMA-[2-(methacryloyloxy)ethyl]trimethylammonium chloride (MOETACl), terpolymer HEMA-MANa-MOETACl and on a polyelectrolyte complex were used as carriers for immobilization of proteins, chicken egg white albumin and avidin. The adsorption capacity of the hydrogels for the two proteins, kinetics and pH dependence of albumin adsorption and desorption were studied. The morphology of the hydrogels with and without immobilized albumin was studied by low-vacuum scanning electron microscopy.
- MeSH
- adsorpce MeSH
- albuminy analýza chemie ultrastruktura MeSH
- avidin analýza chemie ultrastruktura MeSH
- biokompatibilní potahované materiály analýza chemie MeSH
- financování organizované MeSH
- hydrogely analýza chemie MeSH
- kinetika MeSH
- methakryláty analýza chemie MeSH
- poréznost MeSH
- povrchové vlastnosti MeSH
- testování materiálů MeSH
- vazba proteinů MeSH
