共查询到20条相似文献,搜索用时 31 毫秒
1.
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
2.
Fiber-packed SPE tips based on electrospun fibers 总被引:1,自引:0,他引:1
Zhang Y Kang X Chen L Pan C Yao Y Gu ZZ 《Analytical and bioanalytical chemistry》2008,391(6):2189-2197
A novel fiber-packed solid-phase extraction (SPE) tip was designed based on electrospun nanofibers. The tip was used to investigate
the extraction of hydrocortisone (HC), cortisone acetate (CA), ethinylestradiol (EE), and estradiol (E2). The effects of diameters,
porous figurations, and functional groups of the electrospun fibers on the selectivity and efficiency were studied. The experimental
results indicated that the detection limit of cortisol in water sample could be as low as 0.75 ng/mL. When the tip is used
for detection of cortisol in human hair the efficiency of biological sample pretreatment is better than the traditional SPE
method. Our method could significantly simplify the traditional SPE process and lower the cost. Industrial application of
the tip is anticipated.
Figure Analyte molecules (e.g., cortisol) are attracted onto the electrospun nanofibers of the packed SPE tip. Careful selection
of the fiber diameter, morphology, and functional groups affords high selectivity, sensitivity, and extraction recoveries
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
3.
Lillian Roth Jutta Zagon Anke Ehlers Lothar W. Kroh Hermann Broll 《Analytical and bioanalytical chemistry》2009,394(2):529-537
A new approach for the detection of DNA target molecules is described, using capture probes and subsequent signal enhancement
by a uniform polymerase chain reaction (PCR). Peptide nucleic acid probes were immobilized in real-time PCR-compatible microtiter
plates. After hybridization of biotinylated DNA targets, detection was performed by real-time immuno-PCR, a method formerly
used for protein detection. We demonstrate the feasibility of this strategy for the qualitative detection of DNA oligonucleotides
with a detection limit (LOD) of 6 attomol. Furthermore, the method was applied to PCR-amplified samples from genetically modified
maize DNA (Mon810). A 483-bp DNA fragment was detected in mixture with 99.9% of noncomplementary DNA with a sensitivity down
to the level of attomole.
Figure 相似文献
4.
Aristeidis E. Niotis Christos Mastichiadis Panagiota S. Petrou Ion Christofidis Sotirios E. Kakabakos Athanasia Siafaka-Kapadai Konstantinos Misiakos 《Analytical and bioanalytical chemistry》2010,396(3):1187-1196
The early diagnosis of acute myocardial infarction requires the determination of several markers in serum shortly after its
incidence. The markers most widely employed are the isoenzyme MB of creatine kinase (CK-MB) and the cardiac troponin I (cTnI).
In the present work, a capillary waveguide fluoroimmunosensor for fast and highly sensitive simultaneous determination of
these markers in serum samples is demonstrated. The dual-analyte immunosensor was realized using glass capillaries internally
modified with an ultrathin poly(dimethylsiloxane) film by creating discrete bands of analyte-specific antibodies. The capillary
was then filled with a mixture of sample and biotinylated detection antibodies followed by reaction with streptavidin–horseradish
peroxidase and incubation with a fluorescently labeled tyramide derivative to accumulate fluorescent labels onto immunoreaction
bands. Upon scanning the capillary with a laser beam, part of the emitted fluorescence is trapped and waveguided through the
capillary wall to a photomultiplier placed on one of its ends. The employment of tyramide signal amplification provided detection
limits of 0.2 and 0.5 ng/mL for cTnI and CK-MB, respectively, in a total assay time of 30 min compared to 0.8 and 0.6 ng/mL
obtained for the corresponding assays when the conventional fluorescent label R-phycoerythrin was used in a 65-min assay.
In addition, the proposed immunosensor provided accurate and repeatable measurements (intra-assay and interassay coefficients
of variation lower than 10%), and the values determined in serum samples were in good agreement with those obtained with commercially
available enzyme immunoassays. Thus, the proposed capillary waveguide fluoroimmunosensor has all the required characteristics
for fast and reliable diagnosis of acute myocardial infarction.
相似文献
5.
Fanny Kieken Gaud Pinel Jean-Philippe Antignac Fabrice Monteau Anne Christelle Paris Marie-Agnès Popot Yves Bonnaire Bruno Le Bizec 《Analytical and bioanalytical chemistry》2009,394(8):2119-2128
Despite the worldwide existing regulation banning the use of the recombinant equine growth hormone (reGH) as growth promoter,
it is suspected to be used in horseracing to improve performances. Various analytical methods previously developed to screen
for its misuse have encountered some limitations in terms of detection timeframes, in particular during the first days following
reGH administration. A novel strategy involving the characterization of global metabolomic fingerprints in urine samples of
non-treated and reGH-treated horses by liquid chromatography–electrospray–high-resolution mass spectrometry (LC-ESI-HRMS)
is described and assessed in this paper in order to develop a new screening tool for growth hormone abuse in horseracing.
The strategy involves a limited sample preparation of the urine samples and the use of appropriate software for data processing
and analysis. As preliminary work, reproducibility of both sample preparation and mass spectrometry (MS) measurements was
evaluated in order to demonstrate the reliability of the method. Application of the developed protocol on two horses demonstrated
the suitability of the developed strategy and preliminary results showed significant modifications of the metabolome after
treatment with reGH.
相似文献
6.
John Benedet Donglai Lu Karel Cizek Jeff La Belle Joseph Wang 《Analytical and bioanalytical chemistry》2009,395(2):371-376
Rapid detection of the hydrogen peroxide precursor of peroxide explosives is required in numerous security screening applications.
We describe a highly sensitive and selective amperometric detection of hydrogen peroxide vapor at an agarose-coated Prussian-blue
(PB) modified thick-film carbon transducer. The sensor responds rapidly and reversibly to dynamic changes in the level of
the peroxide vapor, with no apparent carry over and with a detection limit of 6 ppbv. The remarkable selectivity of the PB-based
screen-printed electrode towards hydrogen peroxide leads to effective discrimination against common beverage samples. For
example, blind tests have demonstrated the ability to selectively and non-invasively identify concealed hydrogen peroxide
in drinking cups and bottles. The attractive performance of the new microfabricated PB-based amperometric peroxide vapor sensor
indicates great potential for addressing a wide range of security screening and surveillance applications.
Figure Experimental setup (left) with three electrode electrochemical Hydrogen Peroxide sensor hanging above container of “unknown” liquid. Schematic (right) demonstrating fundamental principles of operation of the sensor. 相似文献
7.
Alexander Fabian Le Blanc Christiane Albrecht Tomas Bonn Peter Fechner Günther Proll Florian Pr?ll Mats Carlquist Günter Gauglitz 《Analytical and bioanalytical chemistry》2009,395(6):1769-1776
A novel combined procedure for estrogen-affinity purification and labelling of estrogen receptor α ligand-binding domain with
Cy™ 5.5 cystein reactive dye was established. By using this procedure, mainly functional proteins are recovered. It can be
easily adapted to a large variety of other proteins for which ligand-coated affinity materials are available. The labelled
receptor was used in a total internal reflection fluorescence-based binding inhibition assay for determination of the impact
of pollutants in river water on the receptor. The great advantage compared to conventional methods is that the total effect
on the receptor is measured instead of concentrations of single compounds and that even currently unknown ligands are found
as well. Therefore, the obtained signal is related to the response of the organism, which is exposed to the water. The limit
of detection was found to be 0.139 nM of estradiol equivalents. The assay also provides a highly sensitive tool for pharmaceutical
research and can be adapted to diagnostic applications.
相似文献
8.
Emily O’Neill Danielle Harrington John Allison 《Analytical and bioanalytical chemistry》2009,393(8):2029-2038
Monitoring of cell cultures in microbioreactors is a crucial task in cell bioassays and toxicological tests. In this work
a novel tool based on a miniaturized sensor array fabricated using low-temperature cofired ceramics (LTCC) technology is presented.
The developed device is applied to the monitoring of cell-culture media change, detection of the growth of various species,
and in toxicological studies performed with the use of cells. Noninvasive monitoring performed with the LTCC microelectrode
array can be applied for future cell-engineering purposes.
Figure Microelectrode array for monitoring of cell cultures 相似文献
9.
A method based on use of functionalized gold nanoparticles on polyethylenimine film has been developed for colorimetric detection of immunoglobulin G (IgG). The immunogold nanoparticles were immobilized on quartz slides by recognition between antibody and antigen, with the antigen chemically adsorbed on the polyethylenimine film. By measurement of the UV–visible spectra of the immobilized immunogold, detection of h-IgG was achieved. The detection limit for h-IgG by use of this method can be as low as 0.01 μg mL−1. This method is quite promising for numerous applications in immunoassay.
Figure 相似文献
10.
Tuulia Hyötyläinen 《Analytical and bioanalytical chemistry》2009,394(3):743-758
Sample preparation before chromatographic separation is the most time-consuming and error-prone part of the analytical procedure.
Therefore, selecting and optimizing an appropriate sample preparation scheme is a key factor in the final success of the analysis,
and the judicious choice of an appropriate procedure greatly influences the reliability and accuracy of a given analysis.
The main objective of this review is to critically evaluate the applicability, disadvantages, and advantages of various sample
preparation techniques. Particular emphasis is placed on extraction techniques suitable for both liquid and solid samples.
Figure Miniaturised extraction techniques allow sensitive analysis of also small sample volumes. 相似文献
11.
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
12.
András Gergely Péter Horváth György Szász Gábor Veress 《Analytical and bioanalytical chemistry》2009,394(8):2105-2109
A three-step gradient reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed for the separation
of dehydroepiandrosterone (DHEA), its sulfate ester (DHEA-S), its three C7-oxidized metabolites (7αOH-DHEA, 7βOH-DHEA, 7-keto-DHEA),
and its biosynthetic congeners (androstenedione, testosterone, estradiol, pregnenolone). This new method allows the quantitative
characterization of DHEA metabolism and biosynthetic transformation under given physiological, pathological, or therapeutically
influenced circumstances. Tetrahydrofuran probably acts as a proton acceptor coadsorbent, while isopropanol behaves as a proton
donor during the separation of testosterone, estradiol, and the stereoisomers of 7-OH-DHEA.
Figure Optimized gradient RP-HPLC results in full separation of DHEA from its biosynthetic congeners and metabolites 相似文献
13.
A rapid, specific, and sensitive method has been developed using molecularly imprinted polymers (MIPs) as solid-phase extraction
sorbents for extraction of trace tetracycline antibiotics (TCs) in foodstuffs. MIPs were prepared by precipitation polymerization
using tetracycline as the template. Under the optimal condition, the imprinting factors for MIPs were 4.1 (oxytetracycline),
7.0 (tetracycline), 7.4 (chlortetracycline), 7.7 (doxycycline), respectively. Furthermore, the performance of MIPs as solid-phase
extraction sorbents was evaluated and high extraction efficiency of molecularly imprinted solid-phase extraction (MISPE) procedure
was demonstrated. Compared with commercial sorbents, MISPE gave a better cleanup efficiency than C18 cartridge and a higher
recovery than Oasis HLB cartridge. Finally, the method of liquid chromatography–tandem mass spectrometry coupled with molecular-imprinted
solid-phase extraction was validated in real samples including lobster, duck, honey, and egg. The spiked recoveries of TCs
ranged from 94.51% to 103.0%. The limits of detection were in the range of 0.1–0.3 μg kg−1.
Chromatograms obtained by direct injection of the spiked egg extracts (5 × 10-3 mmol L−1) and purification with MISPE 相似文献
14.
Bo Xu Xiaojun Feng Youzhi Xu Wei Du Qingming Luo Bi-Feng Liu 《Analytical and bioanalytical chemistry》2009,394(7):1911-1917
Analysis of complex biological samples requires the use of high-throughput analytical tools. In this work, a microfluidic
two-dimensional electrophoresis system was developed with mercury-lamp-induced fluorescence detection. Mixtures of 20 standard
amino acids were used to evaluate the separation performance of the system. After fluorescent labeling with fluorescein isothiocyanate,
mixtures of amino acids were separated by micellar electrokinetic chromatography in the first dimension and by capillary zone
electrophoresis in the second. A double electrokinetic valve system was employed for the sample injection and the switching
between separation channels. Under the optimized conditions, 20 standard amino acids were effectively separated within 20 min
with high resolution and repeatability. Quantitative analysis revealed linear dynamic ranges of over three orders of magnitudes
with detection limits at micromolar range. To further evaluate the reliability of the system, quantitative analysis of a commercial
nutrition supplement liquid was successfully demonstrated.
Figure 相似文献
15.
Because variability exists within populations of cells, single-cell analysis has become increasingly important for probing
complex cellular environments. Capillary electrophoresis (CE) is an excellent technique for identifying and quantifying the
contents of single cells owing to its small volume requirements and fast, efficient separations with highly sensitive detection.
Recent progress in both whole-cell and subcellular sampling has allowed researchers to study cellular function in the areas
of neuroscience, oncology, enzymology, immunology, and gene expression.
相似文献
16.
Yi-Heui Hsieh Shih-Jen Liu Hsin-Wei Chen Yao-Kwang Lin Keng S. Liang Lee-Jene Lai 《Analytical and bioanalytical chemistry》2010,396(3):1135-1141
This study presents an efficient and sensitive method for detecting rare cells without cell culture, in which cells are analyzed
quantitatively using quantum dots (QDs) as a fluorescent probe. By the conjugation of QDs with cells, the biotin–streptavidin
reaction functions as a bridge to connect QDs and cells. The cells can be quantified based on the correlation of the QD fluorescence
intensity with the cell population. Non-specific adsorption and cross-reaction of QD625–streptavidin on T cell membrane are
neglected by reacting with biotin anti-human CD3 and mixing with red blood cell, respectively. Additionally, the photo-activation
period and pH can be controlled to enhance the fluorescence of cell populations, which increases linearly with the number
of T cells from 40 to 100,000, not only in a single T cell line but also in mixing with a total of 106 red blood cells. Moreover, the specific T cells can be detected in less than 15 min, even though rare specific cells may
number only 40 cells. Among the advantages, the proposed system for detecting rare cells include simplicity of preparation,
low cost, rapid detection, and high sensitivity, all of which can facilitate the detection of circulating tumor cells in early
stages of diagnosis or prognosis.
相似文献
17.
Sara Wallin Anna Pettersson Henric Östmark Alison Hobro 《Analytical and bioanalytical chemistry》2009,395(2):259-274
A review of standoff detection technologies for explosives has been made. The review is focused on trace detection methods
(methods aiming to detect traces from handling explosives or the vapours surrounding an explosive charge due to the vapour
pressure of the explosive) rather than bulk detection methods (methods aiming to detect the bulk explosive charge). The requirements
for standoff detection technologies are discussed. The technologies discussed are mostly laser-based trace detection technologies,
such as laser-induced-breakdown spectroscopy, Raman spectroscopy, laser-induced-fluorescence spectroscopy and IR spectroscopy
but the bulk detection technologies millimetre wave imaging and terahertz spectroscopy are also discussed as a complement
to the laser-based methods. The review includes novel techniques, not yet tested in realistic environments, more mature technologies
which have been tested outdoors in realistic environments as well as the most mature millimetre wave imaging technique.
Figure Standoff detection and identification is one of the most wanted capabilities 相似文献
18.
Determination of norfloxacin in human urine by capillary electrophoresis with electrochemiluminescence detection 总被引:3,自引:0,他引:3
A fast and sensitive approach that can be used to detect norfloxacin in human urine using capillary electrophoresis with end-column
electrochemiluminescence (ECL) detection of is described. The separation column was a 75-μm i.d. capillary. The running buffer was 15 mmol L−1 sodium phosphate (pH 8.2). The solution in the detection cell was 50 mmol L−1 sodium phosphate (pH 8.0) and 5 mmol L−1
The ECL intensity varied linearly with norfloxacin concentration from 0.05 to 10 μmol L−1. The detection limit (S/N=3) was 0.0048 μmol L−1, and the relative standard deviations of the ECL intensity and the migration time for eleven consecutive injections of 1.0 μmol L−1 norfloxacin (n=11) were 2.6% and 0.8%, respectively. The method was successfully applied to the determination of norfloxacin spiked in human
urine without sample pretreatment. The recoveries were 92.7–97.9%.
相似文献
19.
A magnetocontrolled immunosensing strategy based on flow-injection electrochemical impedance spectroscopy (EIS) was developed
for the determination of carcinoembryonic antigen (CEA) in human serum. The immunosensor was fabricated by immobilizing anti-CEA
on epoxysilane-modified core–shell magnetic Fe3O4/SiO2 nanoparticles. The detection principle is based on the difference between the resistances measured before and after the antigen–antibody
interaction. The performance of the immunosensor and factors influencing this performance were also proposed. The resistance
response depended linearly on the CEA concentration over the range 1.5–60 ng/ml, and the immunosensor gave a detection limit
of 0.5 ng/ml (S/N = 3). Coefficients of variance (CVs) of <9.8% were obtained for the intra- and interassay precisions. The method was successfully
applied to the analysis of CEA in human serum. The recoveries obtained by spiking CEA standards into normal serum were 87–113%.
The performance of the immunosensor was compared with a commercially available CEA ELISA. Satisfactory results were obtained
according to a paired t-test method (t value < t
critical at the 95% confidence level). Importantly, the proposed immobilization protocol could be further developed to immobilize
other antigens or biocompounds.
Figure This study introduced a magnetocontrolled electrochemical immunosensing strategy based on antibody-functionalized magnetic
core–shell Fe3O4/SiO2 nanoparticles for the determination of carcinoembryonic antigen in human serum 相似文献
20.
A novel method for rapid separation and determination of ascorbic acid and uric acid has been developed with a polycation-modified
poly(dimethylsiloxane) (PDMS) microchip under a negative-separation electric field. Just by flushing the microchip with aqueous
solutions of the polycations, poly(allylamine) hydrochloride, poly(diallyldimethylammonium chloride) or chitosan could be
stably coated on the PDMS microchannel surface, which resulted in a reversed electroosmotic flow and thus the rapid and efficient
separation of the two substrates. Factors influencing the separation, including polycation category, buffer solution, detection
potential and separation voltage, were investigated and optimized. The cheapness, rapid analysis speed and the successful
analysis of human urine make this microsystem attractive for application in clinics.
Figure The electropherograms of 100 μ/mL AA and UA in (1) PAH, (2) PDDA, (3) Chitosan modified PDMS microchannels and native PDMS
microchip (4). 相似文献