Immunochemical methods are used not only in clinical practice for the diagnosis of a wide range of diseases but also in basic and advanced research. Based on the unique reaction between the antibody and its respective antigens, it serves to specifically recognize target molecules in biological complex samples. Current methods of labelling antibodies with elemental labels followed by detection by inductively coupled plasma mass spectrometry (ICP-MS) allow detection of multiple antigens in parallel in a single analysis. Using the laser ablation (LA) modality (LA-ICP-MS), it is also possible to monitor the spatial distribution of biogenic elements. Moreover, the employment of metal nanoparticle-labeled antibodies expands the applicability also to molecular imaging by LA-ICP-MS. In this work, conjugates of model monoclonal antibody (DO-1, recognizing p53 protein) with various metal nanoparticles-based labels were created and utilized in dot-blot analysis in order to compare their benefits and disadvantages. Based on experiments with the p53 protein standard, commercial kits of gold nanoparticles proved to be the most suitable for the preparation of conjugates. The LA-ICP-MS demonstrated very good repeatability, wide linear dynamic range (0.1-14 ng), and limit of detection was calculated as a 1.3 pg of p53 protein.
- MeSH
- europium chemie MeSH
- hmotnostní spektrometrie MeSH
- imunoblotting MeSH
- kadmium chemie MeSH
- kovové nanočástice chemie MeSH
- kvantové tečky chemie MeSH
- lasery MeSH
- lidé MeSH
- limita detekce MeSH
- monoklonální protilátky chemie farmakologie MeSH
- nádorový supresorový protein p53 antagonisté a inhibitory MeSH
- stříbro chemie MeSH
- zlato chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
Three 1,4,7,10-tetraazacyclododecane-based ligands disubstituted in 1,4-positions with phosphonic acid, phosphonate monoethyl-ester, and H-phosphinic acid pendant arms, 1,4-H4do2p, 1,4-H2do2pOEt, and 1,4-H2Bn2do2pH, were synthesized and their coordination to selected metal ions, Mg(II), Ca(II), Mn(II), Zn(II), Cu(II), Eu(III), Gd(III), and Tb(III), was investigated. The solid-state structure of the phosphonate ligand, 1,4-H4do2p, was determined by single-crystal X-ray diffraction. Protonation constants of the ligands and stability constants of their complexes were obtained by potentiometry, and their values are comparable to those of previously studied analogous 1,7-disubstitued cyclen derivatives. The Gd(III) complex of 1,4-H4do2p is ~1 order of magnitude more stable than the Gd(III) complex of the 1,7-analogue, probably due to the disubstituted ethylenediamine-like structural motif in 1,4-H4do2p enabling more efficient wrapping of the metal ion. Stability of Gd(III)-1,4-H2do2pOEt and Gd(III)-H2Bn2do2pH complexes is low and the constants cannot be determined due to precipitation of the metal hydroxide. Protonations of the Cu(II), Zn(II), and Gd(III) complexes probably takes place on the coordinated phosphonate groups. Complexes of Mn(II) and alkali-earth metal ions are significantly less stable and are not formed in acidic solutions. Potential presence of water molecule(s) in the coordination spheres of the Mn(II) and Ln(III) complexes was studied by variable-temperature NMR experiments. The Mn(II) complexes of the ligands are not hydrated. The Gd(III)-1,4-H4do2p complex undergoes hydration equilibrium between mono- and bis-hydrated species. Presence of two-species equilibrium was confirmed by UV-Vis spectroscopy of the Eu(III)-1,4-H4do2p complex and hydration states were also determined by luminescence measurements of the Eu(III)/Tb(III)-1,4-H4do2p complexes.
- MeSH
- europium chemie MeSH
- gadolinium chemie MeSH
- heterocyklické sloučeniny chemie MeSH
- komplexní sloučeniny chemická syntéza chemie MeSH
- kontrastní látky MeSH
- krystalografie rentgenová MeSH
- kyseliny fosfinové chemie MeSH
- ligandy MeSH
- magnetická rezonanční spektroskopie MeSH
- mangan chemie MeSH
- organofosfonáty chemie MeSH
- potenciometrie MeSH
- spektrofotometrie ultrafialová MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
We report as a proof-of-concept the first application of circularly polarized luminescence (CPL) measured with a Raman optical activity (ROA) spectrometer to differentiate several DNA structures without need of sensitizing complexes. The ROA/CPL approach provides sufficiently high CPL intensity to use hydrated Eu3+ ions, thus avoiding DNA structural changes associated with binding of sensitizers and overcoming the sensitizer quenching issue. We showed that deoxyguanosine monophosphate (dGMP), single- and double-stranded DNA provide different CPL spectra, which could be used for their discrimination. Our results demonstrate that ROA/CPL method is a promising approach to measure CPL spectra of complex biomolecules when the use of sensitizers is not possible. The method can be extended to other biomolecules, such as proteins, lipids, sugars, etc.
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- MeSH
- Escherichia coli účinky léků MeSH
- europium MeSH
- penetrační peptidy * MeSH
- Schiffovy báze * chemická syntéza MeSH
- spektrofotometrie statistika a číselné údaje MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice statistika a číselné údaje MeSH
- terbium MeSH
- Publikační typ
- práce podpořená grantem MeSH
Lanthanide(III) complexes of 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (H(3)DO3A) are suggested as sensors for sensitive luminescence-based determination of a carbonate anion. Thermodynamic study of association of [Eu(H(2)O)(2)(DO3A)] with bidentate anionic ligands using luminescence spectroscopy reveals an affinity order CO(3)(2-) > oxalate(2-) > picolinate(-) > phthalate(2-) ≈ citrate(3-); presumably as a consequence of an increasing chelate ring size. The ternary [Eu(DO3A)(picolinate)](-) and [Tb(DO3A)(picolinate)](-) complexes show improved photophysical properties due to the antenna effect of the picolinate anion. High quenching effect of carbonate anion and, to a lesser extent also oxalate, enables construction of a linear calibration plot utilizing optimized experimental conditions (e.g. c(LnL) = 0.1 mM, c(picolinate) = 2-5 mM, pH = 7.4, λ(exc) = 286 nm, etc.) for carbonate determination in solution. Both sensors show a comparable sensitivity and the detection limit of about 0.4 mM. In order to improve the photophysical properties of Ln(III) sensor by shift of excitation wavelength about 40 nm to VIS range, the isoquinoline-3-carboxylic acid (IQCA) as antenna ligand was employed instead of picolinic acid. The analysis of commercial samples of European mineral waters was carried out and they were compared to the results obtained by capillary isotachophoresis to confirm there is no inherent (systematic) error to the present analysis. The Ln(III) sensor with IQCA is recommended since it has a better robustness than that with picolinate. The present analytical method is simple and rapid, and it is useful for sensitive determination of bicarbonate/carbonate concentration in water samples under aerobic conditions.
- MeSH
- chemické techniky analytické přístrojové vybavení MeSH
- europium chemie MeSH
- heterocyklické sloučeniny monocyklické chemie MeSH
- ligandy MeSH
- luminiscenční měření MeSH
- makrocyklické sloučeniny chemie MeSH
- organokovové sloučeniny chemie MeSH
- terbium chemie MeSH
- termodynamika MeSH
- uhličitany analýza chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Dielectric properties of Eu(0.5)Ba(0.5)TiO(3) ceramics were investigated between 10 and 300 K in the frequency range of 1 MHz-100 THz. Permittivity exhibits a strong peak near the ferroelectric phase transition at 215 K. This is mainly due to softening of the lowest frequency polar phonon revealed in THz and infrared spectra. Dielectric relaxation was observed also below the ferroelectric soft mode frequency in the whole investigated temperature region, but it is probably caused by some defects such as Eu(3 + ) cations or oxygen vacancies. This implies that the ferroelectric phase transition has predominantly a displacive character. Raman scattering spectra revealed a lowering of crystal symmetry in the ferroelectric phase and XRD analysis indicated orthorhombic A2mm symmetry below 215 K. The magnetic measurements performed at various frequencies in the field cooled and field heating regime after cooling in zero magnetic fields excluded spin glass behavior and proved an antiferromagnetic order below 1.9 K in Eu(0.5)Ba(0.5)TiO(3).
Eu(NO(3))(3) · 5H(2)O and EuCl(3) · 6H(2)O were allowed to react with bis(diphenylphosphino)alkane dioxides Ph(2)P(O)(CH(2))(n) P(O)Ph(2)(n = 2, 4, 6) to obtain polymeric and binuclear complexes. The prepared compounds were structurally characterized by X-ray diffraction. Luminescence measurements (emission and excitation spectra, quantum yields, lifetimes) were compared with crystallographic data in order to find a relationship between luminescent properties of the Eu(III) complexes and their structures. The Eu(III) polymers, especially [Eu(dpphO(2))(2)Cl(2)](+) Cl(-)}(n), have shown extremely long luminescence lifetimes, up to 3.73 ms, as a result of a highly protecting hydrophobic shield.
- MeSH
- europium chemie MeSH
- fosfiny chemie MeSH
- luminiscence MeSH
- molekulární modely MeSH
- oxidy chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Activities of the radionuclides (124)Sb and (152)Eu were determined by the efficiency extrapolation method applied to 4pi(PC)-gamma coincidence counting. The (124)Sb sources were prepared from a solution with the chemical form of 50 microg g(-1) SbCl(3) in 2 M HCl. To inhibit the volatility of antimony chlorides, the sources were slowly dried in a H(2)S atmosphere with relative humidity of 76% for about 48 h. This procedure increased the beta detection efficiency up to 0.98, which simplified the standardisation. In the (152)Eu standardisation, the optimal gamma-ray energy window setting to achieve a linear dependency and the correct slope of the extrapolation curve were derived by means of software coincidence counting system using offline evaluation of data with different coincidence parameter settings. The results obtained by the software coincidence counting system were compared with those obtained by the conventional coincidence method.
- MeSH
- antimon analýza normy MeSH
- europium analýza normy MeSH
- radionuklidy analýza normy MeSH
- referenční standardy MeSH
- software MeSH
- záření gama MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- europium analýza MeSH
- huminové látky MeSH
- koncentrace vodíkových iontů MeSH
- půda MeSH
- rehydratační roztoky MeSH
- Geografické názvy
- Německo MeSH
