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1.
Stratis-Cullum DN Griffin GD Mobley J Vo-Dinh T 《Analytical and bioanalytical chemistry》2008,391(5):1655-1660
This paper reports the first intensified biochip system for chemiluminescence detection and the feasibility of using this
system for the analysis of biological warfare agents is demonstrated. An enzyme-linked immunosorbent assay targeting Bacillus globigii spores, a surrogate species for Bacillus anthracis, using a chemiluminescent alkaline phosphatase substrate is combined with a compact intensified biochip detection system.
The enzymatic amplification was found to be an attractive method for detection of low spore concentrations when combined with
the intensified biochip device. This system was capable of detecting approximately 1 × 105
Bacillus globigii spores. Moreover, the chemiluminescence method, combined with the self-contained biochip design, allows for a simple, compact
system that does not require laser excitation and is readily adaptable to field use.
Figure Schematic diagram of the miniature biochip detection system 相似文献
2.
A supramolecular catalytic kinetic spectrofluorimetric method was developed for the determination of platinum(IV) and the
possible mechanism of catalytic reaction was discussed. The method was based on the fluorescence-enhancing reaction of salicylaldehyde
furfuralhydrazone (SAFH) with potassium bromate, which was catalysed by platinum(IV) in a water–ethanol medium. β–Cyclodextrin (β-CD) obviously sensitized the determination at pH 5.20 and 25°C. Under optimum conditions, the β-CD–platinum–KBrO3–SAFH supramolecular kinetic catalytic reaction system had excitation and emission maxima at 372 and 461 nm, respectively.
The linear range of this method was 0.60–180 ng ml−1 with a relative standard deviation of 1.2%, and the detection limit was 0.18 ng ml−1. Investigation of the mechanism and the effects of interferences is presented. The proposed method was applied successfully
to determine trace platinum(IV) in the chemotherapeutic drug cisplatin and serum from patients with satisfactory results.
相似文献
3.
A new spectrofluorimetric method was developed for the determination of trace amounts of lecithin using the ciprofloxacin (CIP)–terbium (Tb3+) ion complex as a fluorescent probe. In a buffer solution at pH=5.60, lecithin can remarkably reduce the fluorescence intensity of the CIP–Tb3+ complex at λ=545 nm. The reduced fluorescence intensity of the Tb3+ ion is proportional to the concentration of lecithin. Optimum conditions for the determination of lecithin were also investigated. The linear range and detection limit for the determination of lecithin were 1.0×10−6–3.0×10−5 mol L−1 and 3.44×10−7 mol L−1, respectively. This method is simple, practical, and relatively free of interference from coexisting substances. Furthermore, it has been successfully applied to assess lecithin in serum samples.
相似文献
4.
Laser-induced breakdown spectroscopy (LIBS) in liquids using a double-pulse Q-switched Nd:YAG laser system has provided reliable
results that give trace detection limits in water. Resonant laser excitation has been added to enhance detection sensitivity.
A primary laser pulse (at 532 nm), transmitted via an optical fiber, induces a cavitation bubble and shockwave at a target
immersed in a 10 mg l−1–100 mg l−1 indium (In) water suspension. The low-pressure rear of the shockwave induces bubble expansion and a resulting reduction in
cavity pressure as it extends away from the target. Shortly before the maximum diameter is expected, a secondary laser pulse
(also at 532 nm) is fed into the bubble in order to reduce quenching processes. The plasma field generated is then resonantly
excited by a fiber-guided dye laser beam to increase detection selectivity. The resulting resonance fluorescence emission
is optically detected and processed by an intensified optical multichannel analyzer system.
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5.
Gergely A Szász G Szentesi A Gyimesi-Forrás K Kökösi J Szegvári D Veress G 《Analytical and bioanalytical chemistry》2006,384(7-8):1506-1510
The biological importance of dehydroepiandrosterone (DHEA) is reflected by the fact that DHEA is a crucial precursor of the biosynthesis of the steroidal sex hormones. Simultaneous separation of DHEA, dehydroepiandrosterone sulfate (DHEA-S), pregnenolone, androstenedione and testosterone has been accomplished by reversed-phase ion-pair high-performance liquid chromatography (RP-IP-HPLC) based on isocratic elution applying circular dichroism (CD) detection at 295 nm. Addition of tetrabutylammonium hydrogensulfate to the mobile phase increases the retention of DHEA-S on the C8-silica column by an apparent ion-pairing mechanism without affecting the retention of the other (non-ionic) steroids. CD spectroscopy provides highly selective detection of compounds possessing optically active absorption bands and the separation is even more selective in the higher wavelength range applied. The linearity of the steroid concentration (c, mg mL−1) versus peak area was tested in the concentration range of 0.5–2 mg mL−1 (injected quantities were 10–40 μg). The relative standard deviation (RSD) values for DHEA and DHEA-S indicated a good intra-assay and inter-assay precision of the method.
相似文献
6.
Chen XW Xu ZR Qu BY Wu YF Zhou J Zhang HD Fang J Wang JH 《Analytical and bioanalytical chemistry》2007,388(1):157-163
Bead injection in a lab-on-valve (LOV) system was adopted for DNA purification via micro solid-phase extraction (SPE) with
a renewable silica microcolumn packed in a channel of the LOV unit. The complex matrix components in human whole blood, including
proteins, were well eliminated by choosing properly the sample loading and elution media. The DNA purification process was
monitored on-line by using laser-induced fluorescence in a demountable side part of the LOV unit incorporating optical fibers.
The practical applicability of the entire system was demonstrated by separation/purification of λ-DNA in a simulated matrix
and human blood genetic DNA by performing SPE, in situ monitoring of the purified products, and postcolumn PCR amplification.
When DNAs in a simulated matrix (10.0 ng μl−1 λ-DNA, 50 ng μl−1 bovine serum albumin, 1.0% Triton X-100) were processed in the present system and laser-induced fluorescence was monitored
at 610 nm, an overall extraction/collection efficiency of 70% was achieved by employing identical sample loading and an elution
flow rate of 0.5 μl s−1, along with a precision of 3.8% relative standard deviation. DNA separation and purification from human whole-blood samples
were performed under similar conditions.
Figure Lab-on-valve mesofluidic system employed for DNA separation and purification integrating a demountable fluorescence flow cell
for in-situ laser induced fluorescence detection 相似文献
7.
A new flow injection chemiluminescent immunoassay was developed for the detection of 17β-estradiol (E2). The method uses p–iodophenol (PIP) as enhancer and is based on a solid-phase immunoassay format in which an E2–OVA immobilized immunoaffinity column inserted in the flow system is used to trap unbound horseradish peroxidase (HRP)-labeled
anti-E2 antibody after an off-line incubation of E2 with HRP-labeled anti-E2 antibody. The trapped enzyme conjugate was detected by injecting substrates to produce an enhanced chemiluminescence (CL)
response. The linear range for E2 was 10.0–1,000.0 ng mL−1 with a correlation coefficient of 0.996 and a detection limit of 3.0 ng mL−1. The sampling and chemiluminescence detection time for one sample was 400 s after a pre-incubation procedure of 30 min. Serum
samples detected by this method were in good agreement with the results obtained by EIA with E2–biotin.
相似文献
8.
Ortega-Algar S Ramos-Martos N Molina-Díaz A 《Analytical and bioanalytical chemistry》2008,391(2):715-719
A single optosensing device based on lanthanide-sensitized luminescence was developed for determination of p-aminobenzoic acid (PABA). The method is based on the formation of a complex between PABA and Tb(III) immobilized on the solid
phase (QAE A-25 resin) placed inside the flow cell. NaCl (1 M) was used as carrier solution and HCl (0.05 M) as eluent. The
sample solutions of PABA (100 μL) containing Tb(III) and buffered at pH = 6.0 were injected into the carrier stream and the
luminescence was measured at λ
ex = 290 nm and λ
em = 546 nm. The method shows a linear range from 0.2 to 6.0 μg mL−1 with an RSD of 1.2% (n = 10) and a sampling frequency of 22 h−1. A remarkable characteristic of the method is its high selectivity which allows it to be satisfactorily applied to the analysis
of PABA in pharmaceutical samples without prior treatment.
Figure Typical emission bands of Tb(III) in a solid-phase PABA–Tb(III) luminescence spectrum 相似文献
9.
Stolper P Fabel S Weller MG Knopp D Niessner R 《Analytical and bioanalytical chemistry》2008,390(4):1181-1187
A new type of biodetector was designed based on a bioluminescence test with the bacterium Vibrio fischeri performed in a liquid continuous flow-through system. Here we describe the modification of a commercial tube luminescence
detector to work in the flow mode by building a new flow cell holder and a new case including “top cover” to connect the flow
cell with the waste and the incubation capillary in a light-proof manner. As different samples were injected successively
it was necessary to keep the individual peaks separated. This was done using an air-segmented flow in the reaction coil. To
afford fast screening, the incubation time of the sample and the Vibrio fischeri, which equaled the dead time of the detection system, was set at 5.6 min. Rapid monitoring of toxic substances is achieved
by using 20 μL of sample and flow-rates of 110–150 μL min−1. As a proof-of-principle, we show results for the detection of five selected di-, tri- and tetrachlorophenols at different
concentrations varying from 1 to 200 mg L−1. Calculation of inhibition rates and EC50 values were performed and compared with corresponding values from the DIN EN ISO 11348-2 microplate format. Compared with
the latter, the inhibition rates obtained with our flow-through biodetector for the compounds tested were generally about
twofold lower, but importantly, a much faster detection is possible.
Figure Flow scheme of the biodetector setup 相似文献
10.
Determining sulfamonomethoxine and its acetyl/hydroxyl metabolites in chicken plasma under organic solvent-free conditions 总被引:1,自引:0,他引:1
Furusawa N 《Analytical and bioanalytical chemistry》2006,385(8):1570-1574
A quantitative technique is described for a sample preparation followed by high performance liquid chromatography method for
the simultaneous determination of sulfamonomethoxine and its metabolites, N
4-acetyl SMM and 2,6-dihydroxy SMM, in chicken plasma. The average recoveries, analytical total time, and limits of quantitation
were ≥80% (relative standard deviations (SD) ≤6%), <30 min sample-1 (12 samples in 2 h), and ≤0.09 μg ml−1, respectively. The procedure, performed under 100% aqueous conditions, uses no organic solvents and toxic reagents at all
and is, therefore, harmless to the environment and humans.
相似文献
11.
Michelle M. Martinez Randall D. Reif Dimitri Pappas 《Analytical and bioanalytical chemistry》2010,396(3):1177-1185
Early detection of apoptotic cells via caspase activity is demonstrated with fast response time. Fluorescence correlation
spectroscopy (FCS) is used to identify the presence of a cleaved fluorogenic probe based on the fluorescence of rhodamine
110 in Jurkat cells. FCS curves are shown to be markedly different for autofluorescent (non-apoptotic) cells, whereas cells
with cleaved probe showed diffusion and molecular brightness characteristic of rhodamine 110. Using FCS measurements, cells
were identified as apoptotic on the basis of the presence of autocorrelated fluorescence, average molecular brightness (η), and molecular dwell time (τ
D). Apoptotic cells identified in this manner were detected as early as 45 min after induction. Unlike other methods with similar
identification times, such as western blotting and electron microscopy, cells remain viable for further analysis. This multi-parameter
approach is rapid, flexible, and does not require transfection of the cells prior to analysis, enabling apoptosis to be identified
early in a wide variety of cell types.
相似文献
12.
Khalid Hamad Abu-Shandi 《Analytical and bioanalytical chemistry》2009,395(2):527-532
A high-performance liquid chromatographic (HPLC) method with fluorescence detection for the quantification of vancomycin in
human plasma was developed and validated. The method includes an extraction of vancomycin by deproteinization with acetonitrile.
The analyses were carried out at 258 nm as the emission wavelength while exciting at 225 nm on a reversed-phase column (30 cm × 4 mm
i.d. × 10 μm Waters Associates μBondapak C18) using a mobile phase composed of methanol and phosphate buffer at pH 6.3. Vancomycin
was quantitatively recovered from human plasma samples (>96%) with high values of precision. The separation was completed
within 27 min. The calibration curve was linear over the range from 5 to 1,000 ng/mL with the detection and quantification
limits of 2 ng/mL and 5 ng/mL, respectively. This method is suitable for the routine assay of plasma samples.
Figure The effect of the deproteinization solvent on the signal of the interference peak at retention time of 15.0 min. The peak
which interferes with the peaks of Erythromycin and Vancomycin has been disappeared by using 2 mL acetonitrile as the deproteinization
solvent. 相似文献
13.
Limbut W Hedström M Thavarungkul P Kanatharana P Mattiasson B 《Analytical and bioanalytical chemistry》2007,389(2):517-525
A capacitive biosensor for the detection of bacterial endotoxin has been developed. Endotoxin-neutralizing protein derived
from American horseshoe crab was immobilized to a self-assembled thiol layer on a biosensor transducer (Au). Upon injection
of a sample containing endotoxin, a decrease in the observed capacitive signal was registered. Endotoxin could be determined
under optimum conditions with a detection limit of 1.0 × 10−13 M and linearity ranging from 1.0 × 10−13 to 1.0 × 10−10 M. Good agreement was achieved when applying endotoxin preparations purified from an Escherichia coli cultivation to the capacitive biosensor system, utilizing the conventional method for quantitative endotoxin determination,
the Limulus amebocyte lysate test as a reference. The capacitive biosensor method was statistically tested with the Wilcoxon signed rank test, which proved
the system is acceptable for the quantitative analysis of bacterial endotoxin (P < 0.05).
Figure The flow-injection capacitive biosensor system and the capacitive properties of the transducer surface, where CSAM is the capacitance change of the self-assembled thiol monolayer, CP is the capacitance change of the protein layer, Ca is the capacitance change of the analyte layer and CTotal is the total capacitance change measured at the working electrode/solution interface (modified from Limbut et al., 2006.
Biosens Bioelectron 22: 233-240) 相似文献
14.
Patricia W. Stege Lorena L. Sombra Germán A. Messina Luis D. Martinez María F. Silva 《Analytical and bioanalytical chemistry》2009,394(2):567-573
Many aromatic compounds can be found in the environment as a result of anthropogenic activities and some of them are highly
toxic. The need to determine low concentrations of pollutants requires analytical methods with high sensitivity, selectivity,
and resolution for application to soil, sediment, water, and other environmental samples. Complex sample preparation involving
analyte isolation and enrichment is generally necessary before the final analysis. The present paper outlines a novel, simple,
low-cost, and environmentally friendly method for the simultaneous determination of p-nitrophenol (PNP), p-aminophenol (PAP), and hydroquinone (HQ) by micellar electrokinetic capillary chromatography after preconcentration by cloud
point extraction. Enrichment factors of 180 to 200 were achieved. The limits of detection of the analytes for the preconcentration
of 50-ml sample volume were 0.10 μg L−1 for PNP, 0.20 μg L−1 for PAP, and 0.16 μg L−1 for HQ. The optimized procedure was applied to the determination of phenolic pollutants in natural waters from San Luis,
Argentina.
Figure Schematic representation of the cloud point extraction process. 相似文献
15.
Analytical procedure for determination of the time profile of eprinomectin excretion in sheep faeces
Kozuh Erzen N Hodoscek L Cerkvenik-Flajs V 《Analytical and bioanalytical chemistry》2007,387(4):1329-1335
An analytical procedure has been introduced to enable study of the time profile of eprinomectin excretion in sheep faeces.
Eprinomectin was extracted from sheep faeces with acetonitrile, the extract was cleaned by solid-phase extraction (SPE), and,
after derivatization by reaction with N-methylimidazole, trifluoroacetic anhydride, and acetic acid, eprinomectin was analysed by high-performance liquid chromatography
(HPLC) with fluorescence detection. The method has a low detection limit (1.0 ng g−1 of moist sheep faeces), a low quantification limit (2.5 ng g−1 of moist sheep faeces), good recovery (in the range 78.8 to 87.1%), and good reproducibility (RSD<10%). The method was used
to study the time-profile of excretion of eprinomectin in sheep faeces after a single topical administration of 0.5 mg kg−1 b.w. of the drug. Because of its good recovery, precision, and sensitivity, the method has also proved applicable to further
ecotoxicological studies of eprinomectin.
Figure Autochthonous Slovenian dairy breed sheep – Istrian Pramenka 相似文献
16.
An X-ray fluorescence method (XRF) is presented that allowed low detection limits (at the 0.1–23 ng mL−1 level) to be obtained for Cr, Mn, Fe, Ni, Zn, Sr, Pb, Bi and Br in water. The samples were prepared using a thin layer method. Trace elements were determined via the calibration curve and standard addition. Absorption effects and inhomogenities in prepared samples were checked for using the emission–transmission method and internal standards, respectively. The results from the XRF method were compared with the results from the inductively coupled plasma atomic emission spectrometry method.
相似文献
17.
Tragoulias SS Obeid PJ Tataridis IE Christopoulos TK 《Analytical and bioanalytical chemistry》2008,390(6):1563-1573
Microarray technology covers the urgent need to exploit the accumulated genetic information from large-scale sequencing projects
and facilitate investigations on a genome-wide scale. Although most applications focus on DNA microarrays, the technology
has expanded to microarrays of proteins, peptides, carbohydrates, and small molecules aiming either at detection/quantification
of biomolecules or investigation of biomolecular interactions in a massively parallel manner. Microarray experiments require
two specialized instruments: An arrayer (or printer), for construction of microarrays, and a readout instrument (scanner).
We have designed, constructed, and characterized the first integrated microarray system (IMAS) that combines the functions
of a microarrayer and a three-laser confocal fluorescence scanner into a single instrument and provides excellent flexibility
for the researcher. The three-axis robotic system that moves the printing head carrying multiple pins for arraying is also
used for moving the microarray slide in front of a stationary optical system during scanning. Since the translation stages
are the most expensive and crucial components of microarray printers and scanners, the proposed design reduces considerably
the cost of the instrument and enhances remarkably its operative flexibility. Experiments were carried out at resolutions
of 2.5, 5, 10, and 20 μm. The scanner detects 0.128 nmol L−1 carboxyfluorescein (spots with diameters of 70 μm) corresponding to 1.8 molecules μm−2. The linear range extends over 3.5 orders of magnitude (R
2 = 0.997) and the dynamic range covers almost five orders of magnitude. DNA microarray model experiments were carried out,
including staining with SYBR Green I and hybridization with oligonucleotides labeled with the fluorescent dyes Alexa 488,
Alexa 594, and Alexa 633.
Figure Lay-out of the home-built integrated microarray system (IMAS). For the first time, the functions of a microarrayer (printer)
and a three-laser confocal fluorescence scanner are combined into a single instrument. The three-axis robotic system that
moves the printing head for arraying is also used to move the microarray slide in front of a stationary optical system during
scanning.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
18.
Zakir Hossain SM Shinohara H Wang F Kitano H 《Analytical and bioanalytical chemistry》2007,389(6):1961-1966
There is an increasing interest in new strategies to detect neurotransmitters released from nerve cells in real time for brain
science, drug assessment, and so on. Previously we reported real-time monitoring of dopamine release from nerve model cells
by enzyme-catalyzed luminescence measurement with tyramine oxidase and peroxidase. In the present study, the system was modified
with glutamate oxidase instead of tyramine oxidase to detect L-glutamate sensitively (≈ 10 nM) and rapidly with high temporal resolution (<1 s). We applied this modified method successfully
to perform real-time monitoring of L-glutamate release from brain model cell (C6 glioma cell) using a luminescence plate reader upon stimulation with high concentration
of KCl (>10 mM) or 5-hydroxytryptamine (>1 μM). The measurement solution was not toxic and therefore the L-glutamate release from the cell was measured by the second stimulation after exchanging the measurement solution. We conclude
that the developed monitoring system is suitable for real-time detection of dynamic L-glutamate release from nerve cells in vitro and will be suitable for application in assessment of drugs acting on the nervous
system.
Figure Enzyme luminescence detection of L-glutamate released from cells 相似文献
19.
Yan Xiong Jing Xu Jian-Wei Wang Ya-Feng Guan 《Analytical and bioanalytical chemistry》2009,394(3):919-923
We have prepared a novel fiber-optic evanescent wave sensor (FEWS) for dissolved oxygen (DO) detection. The sensor fabrication
was based on coating a decladded portion of an optical fiber with a microporous coating, which was prepared from 3,3,3-trifluoropropyltrimethoxysilane
and n-propyltrimethoxysilane. The fluorophores were immobilized in the porous coating and excited by the evanescent wave field
produced on the core surface of the optical fiber. The sensitivity of the sensor was quantified by the ratio of the fluorescence
intensities in pure deoxygenated (I
0) and in pure oxygenated environments (I). Results show that the quenching response of DO is increased with the enhancement of the coating surface hydrophobicity
using the presented hybrid fluorinated ORMOSILs. The calibration curve of I
0/I to [O2] is linear from 0 to 40 ppm and the detection limit is 0.05 ppm (3σ) with a short response time of 15 s for DO detection.
Figure 相似文献
20.
Destandau E Lefèvre JP Chouai Fakhr Eddine A Desportes S Jullien MC Hierle R Leray I Valeur B Delaire JA 《Analytical and bioanalytical chemistry》2007,387(8):2627-2632
A microfabricated device has been developed for fluorimetric detection of potassium ions without previous separation. It is
based on use of a fluorescent molecular sensor, calix–bodipy, specially designed to be sensitive to and selective for the
target ion. The device is essentially made of a Y-shape microchannel moulded in PDMS fixed on a glass substrate. A passive
mixer is used for mixing the reactant and the analyte. The optical detection arrangement uses two optical fibres, one for
excitation by a light-emitting diode, the other for collection of the fluorescence. This system enabled the flow-injection
analysis of the concentration of potassium ions in aqueous solutions with a detection limit of 0.5 mmol L−1 and without interference with sodium ions. A calibration plot was constructed using potassium standard solutions in the range
0–16 mmol L−1, and was used for the determination of the potassium content of a pharmaceutical pill.
Figure Photography of the microfluidic channel showing the ridges in the PDMS substrate at the top of the channel 相似文献