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1.
Webb A 《Analytical and bioanalytical chemistry》2007,388(3):525-528
Figure Schematic diagram of a typical arrangement used for hyphenating chemical microseparations (e.g. capillary HPLC, CE, or CEC)
with microcoil NMR detection 相似文献
2.
Lee JO So HM Jeon EK Chang H Won K Kim YH 《Analytical and bioanalytical chemistry》2008,390(4):1023-1032
Recent advances in nanotechnology have enabled the development of nanoscale sensors that outperform conventional biosensors.
This review summarizes the nanoscale biosensors that use aptamers as molecular recognition elements. The advantages of aptamers
over antibodies as sensors are highlighted. These advantages are especially apparent with electrical sensors such as electrochemical
sensors or those using field-effect transistors.
Figure Feeling proteins with aptamer-functionalized carbon nanotubes 相似文献
3.
Templating is an effective way for the structural modifications of a material and hence for altering its functional properties.
Here protein imprinting was exploited to alter polymeric polyacrylamide (PAA) membranes. The sieving properties and selection
abilities of the material formed were evaluated by studying the electrically driven transport of various proteins across templated
PAA membranes. The sieving properties correlated with the templating process and depended on the quantity of template used
during the polymerisation. For 1 mg/mL protein-templated membranes a ‘gate effect’ was shown, which induced a preferential
migration of the template and of similar-size proteins. Such template preferential electrotransport was exploited for the
selective removal of certain proteins in biological fluids prior to proteome analysis (depletion of albumin from human serum);
the efficiency of the removal was demonstrated by analysing the serum proteome by two-dimensional electrophoresis experiments.
Figure PAA templeted membrane for the electroremoval of serum albumin before proteome analysis 相似文献
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The derivatization of cysteine-containing peptides with benzoquinone compounds is rapid, quantitative and specific in acidic
media. The conversion of cysteines into hydrophobic benzoquinone-adducted residues in peptides is used here to alter the chromatographic
properties of cysteinyl peptides during liquid chromatography separation. The benzoquinone derivatization is shown to allow
the accurate selection of cysteine-containing peptides of bovine serum albumin tryptic digest by diagonal reversed-phase chromatography,
which consists of one primary and a series of secondary identical liquid chromatographic separations, before and after a cysteinyl-targeted
modification of the peptides by benzoquinone compounds.
Figure Diagonal chromatographic selection of cysteinyl peptides modified with benzoquinones
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
7.
Ma X Zhu T Xu H Li G Zheng J Liu A Zhang J Du H 《Analytical and bioanalytical chemistry》2008,390(4):1133-1137
A chemical prototype sensor was constructed based on nanofiber-structured TiO2 and highly sensitive quartz resonators. The gas-sensing behavior of this new sensor to selected simulant warfare agents was
investigated at room temperature. Results showed rapid response and good reversibility of this sensor when used with high-purity
nitrogen. This provides a simple approach to preparation of materials needed as chemical sensors for selected organic volatiles
or warfare agents.
Figure Sensing behavior of TiO2 nanofiber sensor to chemical vapors 相似文献
8.
Fakhrullin RF Vinter VG Zamaleeva AI Matveeva MV Kourbanov RA Temesgen BK Ishmuchametova DG Abramova ZI Konovalova OA Salakhov MK 《Analytical and bioanalytical chemistry》2007,388(2):367-375
We report the development of a novel quartz crystal microbalance immunosensor with the simultaneous measurement of resonance
frequency and motional resistance for the detection of antibodies to double-stranded DNA (dsDNA). The immobilization of poly(l-lysine) and subsequent complexation with DNA resulted in formation of a sensitive dsDNA-containing nanofilm on the surface
of a gold electrode. Atomic force microscopy has been applied for the characterization of a poly(l-lysine)–DNA film. After the blocking with bovine serum albumin, the immunosensor in flow-injection mode was used to detect
the antibodies to dsDNA in purified protein solutions of antibodies to dsDNA and to single-stranded DNA, monoclonal human
immunoglobulin G, DNase I and in blood serum of patients with bronchial asthma and systemic lupus erythematosus. Experimental
results indicate high sensitivity and selectivity of the immunosensor.
In memoriam Prof. Victor G. Vinter 相似文献
9.
Cordes DB Miller A Gamsey S Singaram B 《Analytical and bioanalytical chemistry》2007,387(8):2767-2773
The simultaneous use of several fluorescent reporter dyes in a multicomponent boronic acid-based glucose sensing system is
reported. In one application, two dyes with widely different emission wavelengths are used to report changes in glucose concentration.
A third glucose-insensitive dye was then added to act as a reference dye and provide for a ratiometric correction to the two
reporter dye signals. The inclusion of such a reference dye reduces errors arising from sources such as fluctuations in lamp
intensity and sample dilution.
The simultaneous use of multiple fluorescent reporter dyes 相似文献
10.
Surmeian A Diplasu C Groza A Ganciu M Belenguer P Tempez A Chapon P 《Analytical and bioanalytical chemistry》2007,388(8):1625-1629
A high-current pulsed hollow cathode discharge was used to study the role of atomic and ionic metastables involved in ionization
plasma processes. We observed the enhancement of the spectral emission lines of noble gas ions in the afterglow. A study of
the processes that involve atomic and ionic metastables is of great interest since it should lead to a better understanding
of and enhanced control over the ionization mechanisms crucial to analytical glow discharge mass spectrometry (GDMS) analysis.
Figure Time profile of Ti, Ti+, and Ne+ spectral lines 相似文献
11.
Ortner K Sivanandam VN Buchberger W Müller N 《Analytical and bioanalytical chemistry》2007,388(1):173-177
Enzymatically cleaved glycans from sub-milligram quantities of erythropoietin (EPO) and ovalbumin have been analyzed, without
further purification, by two-dimensional diffusion-ordered nuclear magnetic resonance spectroscopy. At NMR sample concentrations
below 50 μmol L−1 the major components of the oligosaccharide fractions could be distinguished by their anomeric proton chemical shift and
their size-dependent diffusion coefficients.
Figure
1H NMR diffusion decay curves of anomeric protons in the EPO glycan fraction 相似文献
12.
Martens T Bogaerts A Brok W van Dijk J 《Analytical and bioanalytical chemistry》2007,388(8):1583-1594
A model developed for a dielectric barrier discharge (DBD) in helium, used as a new spectroscopic source in analytical chemistry,
is presented in this paper. The model is based on the fluid approach and describes the behavior of electrons, He+ and ions, He metastable atoms, He atoms in higher excited levels, and He2 dimers. The He ground-state atoms are regarded as background gas. The characteristic effect of charging/discharging of the
dielectrics which cover both electrodes is also simulated. Typical results of the model include the distribution of potential
inside the plasma (and the potential drop across the dielectrics), the electric current and gap voltage as a function of time
for a given applied potential profile, the spatial and temporal number-density profiles of the different plasma species, and
the relative contributions of the mechanisms of their production and loss.
Figure Schematic diagram of the dielectric barrier discharge (left) and typical temporal profiles of voltage and current, as obtained
from the simulations (right) 相似文献
13.
Rodríguez-Fariñas N Gomez-Gomez MM Camara-Rica C 《Analytical and bioanalytical chemistry》2008,390(1):29-35
Oral administration of sodium tungstate is an effective treatment for type 1 and 2 diabetes in animal models; it does not
incur significant side effects, and it may constitute an alternative to insulin. However, the mechanism by which tungstate
exerts its observed metabolic effects in vivo is still not completely understood. In this work, serum-containing proteins
which bind tungstate have been characterized. Size exclusion chromatography (SEC) coupled to inductively coupled plasma mass
spectrometry (ICP-MS) with a Phenomenex Bio-Sep-S 2000 column and 20 mM HEPES and 150 mM NaCl at pH 7.4 as the mobile phase
was chosen as the most appropriate methodology to screen for tungsten–protein complexes. When human serum was incubated with
tungstate, three analytical peaks were observed, one related to tungstate–albumin binding, one to free tungstate, and one
to an unknown protein binding (MW higher than 300 kDa). Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF)
mass spectrometric analysis of the tungsten-containing fractions collected from SEC–ICP-MS chromatograms, after desalting
and preconcentration processes, confirmed the association of tungstate with albumin and the other unknown protein.
Figure SEC-ICP-MS // MALDI-TOF 相似文献
14.
Schaffer B Grogger W Kothleitner G Hofer F 《Analytical and bioanalytical chemistry》2008,390(6):1439-1445
In this work we show how energy-filtered imaging can be used to obtain spectrum images of electron energy-loss spectrometric
data. Focus is placed on improved energy resolution within these data sets. Using two multilayer samples (GaN/AlN and InP/InAs),
we demonstrate the advantages of spectrum-imaging and its extended mapping capabilities. Plasmon-ratio maps are used to quickly
create high-contrast material maps with high signal-to-noise ratio, ratio-contrast plots are used to gain optimum settings
for the ratio maps, and plasmon-position maps are used to map small shifts of the energy position of bulk plasmon peaks.
Figure Scheme of EELS SI and derived plasman-position map 相似文献
15.
Goryacheva IY Basova EY Van Peteghem C Eremin SA Pussemier L Motte JC De Saeger S 《Analytical and bioanalytical chemistry》2008,390(2):723-727
A rapid easy-to-use immunoassay was optimised for the non-instrumental detection of ochratoxin A (OTA) in beer. The analytical
method involves preconcentration on the immunoaffinity layer inside a column followed by direct competitive ELISA detection
in the same layer. The visual cut-off value, i.e. the lowest OTA concentration resulting in no colour development, was 0.2 μg
L-1. Assay validation was performed using samples spiked with OTA. Thirty-seven naturally contaminated samples were screened
with the gel-based method developed and no false-negative results were obtained. The method described offers a simple, rapid
and cost-effective screening tool, thus contributing to better health protection of consumers.
Figure Gel-based immunoassay of spiked beer samples. 相似文献
16.
The integration of a range of technologies including microfluidics, surface-enhanced Raman scattering and confocal microspectroscopy
has been successfully used to characterize in situ single living CHO (Chinese hamster ovary) cells with a high degree of spatial (in three dimensions) and temporal (1 s per spectrum) resolution. Following the introduction of a continuous flow of ionomycin, the real time spectral response
from the cell was monitored during the agonist-evoked Ca2+ flux process. The methodology described has the potential to be used for the study of the cellular dynamics of a range of
signalling processes.
Figure Spectral mapping of a single CHO cell 相似文献
17.
An impurity-profiling method for 3,4-methylenedioxymethamphetamine (MDMA) is presented. The impurities of interest were extracted
by solid-phase extraction (SPE) on Bakerbond C18 spe columns from a weakly alkaline solution (pH 8.5). Development of the extraction conditions covered selection of the buffer
for dissolution of the sample and the volume of the eluent used to elute the impurities. An important part of the studies
was to optimise the separation conditions, and the simplex method was used for this purpose. Cluster analysis was applied
for comparison of samples and its grouping. The developed method was based on the areas of 33 selected peaks corresponding
to MDMA impurities. All examined samples were correctly classified into clusters corresponding to the synthetic route.
相似文献
18.
Fernández-Alvarez M Lores M Llompart M García-Jares C Cela R 《Analytical and bioanalytical chemistry》2007,388(5-6):1235-1247
In the present study, solid-phase microextraction in photochemical studies was used to investigate UV light induced photodegradation
of five pyrethroids (empenthrin, transfluthrin, allethrin, phenothrin and cyphenothrin) and a synergist (piperonyl butoxide),
which are common ingredients of household insecticides. Gas chromatography coupled with mass spectrometry was used to separate
and tentatively identify the parent compounds and their corresponding photoproducts generated in the same polydimethylsiloxane
fibre. Kinetics curves were obtained and apparent first-order rate constants and half-lives were estimated. Twenty-six photoproducts
were tentatively identified and photodegradation pathways for the compounds investigated were proposed. It is a matter of
some concern that three of the photoproducts identified [(3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid, 3-phenoxybenzaldehyde
and (3-phenoxyphenyl)methanol] have been reported to be endocrine disruptors. There is no record of previous studies of cyphenothrin
and empenthrin photodegradation, and therefore the present study represents the first attempt to elucidate the photochemical
behaviour of these compounds.
Figure Photo-SPME for Pyrethroids 相似文献
19.
Astel A Tsakovski S Simeonov V Reisenhofer E Piselli S Barbieri P 《Analytical and bioanalytical chemistry》2008,390(5):1283-1292
The present study deals with the application of self-organizing maps (SOM) and multiway principal-components analysis to classify,
model, and interpret a large monitoring data set for surface water quality. The chemometric methods applied made it possible
to reveal specific quality patterns of the chemical and biological parameters used to monitor the water quality (relation
between water temperature, turbidity, hardness, colibacteria), seasonal impacts during the long period of observation and
the relative independence on the spatial location of the sampling sites (water supply sources for the City of Trieste).
Figure The schematic procedure for surface water pollution estimation supported by neural network-based classification and multivariate factor
analysis 相似文献
20.
Acetone plays an important role in the chemistry of both the atmosphere and the ocean, due to its potential effect on the
tropospheric HOx (= HO + HO2) budget, as well as its environmental and health effects. We discuss the development of a mobile, sensitive, selective, economical
and facile method for the determination of acetone in seawater. The method consists of derivatizing acetone to its pentafluorobenzyl
oxime using 1,2,3,4,5-pentafluorobenzylhydroxylamine (PFBHA), followed by solid-phase microextraction (SPME) and analysis
by gas chromatography/mass spectrometry (GC/MS). A detection limit of 3.0 nM was achieved. The buffering capacity of seawater
imposes challenges in using the method’s optimum pH (3.7) on seawater samples, requiring calibration standards to be made
in buffered salt water and the acidification of seawater samples and standards prior to extraction. We employed the technique
for analysis of selected surface seawater samples taken on the Nordic seas during the ARK-XX/1 cruise (R.V. Polarstern). An upper limit of 5.5–9.6 nM was observed for acetone in these waters, the first acetone measurements reported for far
North Atlantic and Arctic waters.
Simplified schematic of transformations of organic compounds at the atmosphere–ocean interface 相似文献