共查询到20条相似文献,搜索用时 31 毫秒
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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
4.
SPME in environmental analysis 总被引:1,自引:0,他引:1
Recent advances in the use of solid-phase microextraction (SPME) in environmental analysis, including fiber coatings, derivatization
techniques, and in-tube SPME, are reviewed in this article. Several calibration methods for SPME, including traditional calibration
methods, the equilibrium extraction method, the exhaustive extraction method, and several diffusion-based calibration methods,
are presented. Recent developed SPME devices for on-site sampling and several applications of SPME in environmental analysis
are also introduced.
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5.
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
6.
Thin nanoporous alumina obtained by anodization of aluminum films offers promising advantages for application in fluorescence-based biological sensors including convenient preparation, increased density of binding sites, and improved collection efficiency of fluorescence. These advantages are illustrated in the detection of streptavidin using biotin covalently bound to the surface of alumina nanopores. Fluorescence intensity enhancement as high as 7 times is observed in nanopores in comparison to flat glass surface.
相似文献
7.
A nonradioactive 31P nuclear magnetic resonance (NMR) spectroscopy protocol has been developed and used to investigate in vitro autophosphorylation of insulin receptors. Optimum experimental conditions have been explored, and the effects of Mn2+ and phosphocreatine (PCr) on the determination of the phosphorylation reaction have been assayed. The method was used to monitor the time courses of the phosphorylation reaction in solution. The results from this NMR study were in agreement with observations of insulin receptor phosphorylation made by using Western blotting.
相似文献
8.
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
9.
Herschbach H Hosomizu K Hahn U Leize E Van Dorsselaer A Imahori H Nierengarten JF 《Analytical and bioanalytical chemistry》2006,386(1):46-51
The electrospray mass spectrometric characterization of neutral dendrons with a carboxylic acid function or a t-butyl ester moiety at the central point and up to eight peripheral C60 subunits has been performed and is described in detail. Molecules bearing a carboxylic acid group at the center turned out
to be preferentially ionized by deprotonation, whereas those with a t-butyl ester head group were ionized by reduction of the C60 units in the infusion capillary of the electrospray source.
Electronic supplementary material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
10.
Pérez Pavón JL García Pinto C Guerrero Peña A Moreno Cordero B 《Analytical and bioanalytical chemistry》2008,391(2):599-607
In the present work we report the results obtained with a methodology based on direct coupling of a headspace generator to
a mass spectrometer for the identification of different types of petroleum crudes in polluted soils. With no prior treatment,
the samples are subjected to the headspace generation process and the volatiles generated are introduced directly into the
mass spectrometer, thereby obtaining a fingerprint of volatiles in the sample analysed. The mass spectrum corresponding to
the mass/charge ratios (m/z) contains the information related to the composition of the headspace and is used as the analytical signal for the characterization
of the samples. The signals obtained for the different samples were treated by chemometric techniques to obtain the desired
information. The main advantage of the proposed methodology is that no prior chromatographic separation and no sample manipulation
are required. The method is rapid, simple and, in view of the results, highly promising for the implementation of a new approach
for oil spill identification in soils.
Figure PCA score plots illustrate clear discrimination of types of crude oil in polluted soil samples (e.g. results are shown for
vertisol) 相似文献
11.
Bonanni A Esplandiu MJ Pividori MI Alegret S del Valle M 《Analytical and bioanalytical chemistry》2006,385(7):1195-1201
Impedance spectroscopy is proposed as the transduction principle for detecting the hybridization of DNA complementary strands.
In our experiments, different DNA oligonucleotides were used as model gene substances. The gene probe is first immobilized
on a graphite-epoxy composite working electrode based genosensor. Detection principle is based on changes of impedance spectra
of a redox marker, the ferro/ferricyanide couple, after hybridization with target DNA. Resistance offered to the electrochemical
reaction serves as the working signal, allowing for an unlabelled gene assay.
相似文献
12.
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
13.
A chemiluminescent (CL) detection method has been developed for DNA hybridization. The assay relies on a sandwich-type DNA
hybridization in which gold nanoparticles modified with alkylthiol-capped oligonucleotide strands are used as probes to monitor
the presence of the specific target DNA. The , which is the dissolving product of the gold nanoparticles anchored on the DNA hybrids, serves as an analyte in the H2O2–luminol– CL reaction for the indirect measurement of the target DNA. The combination of the remarkable sensitivity of the CL analysis
with the large number of released from each DNA hybrid allows a detection limit at levels as low as 0.1 pM of the target DNA. Moreover, with a further
silver amplification step, the detection limit will be pushed down to the femtomolar domain.
相似文献
14.
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.
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15.
Hinrichs K Gensch M Esser N Schade U Rappich J Kröning S Portwich M Volkmer R 《Analytical and bioanalytical chemistry》2007,387(5):1823-1829
The standard methods currently used to read out microarrays are fluorescent and chemiluminesent imaging techniques. These
methods require labeling of a component with a marker and, usually, only the concentration of the marker molecule is detected.
A label-free imaging method that also enables quantitative spectroscopic analysis of the composition and component interaction
would be of great advantage. In this article it is shown for the first time that IR mapping ellipsometry enables label-free
imaging of a biochip before and after incubation with peptide solution. The measurements prove that IR ellipsometry is a sensitive
tool for laterally resolved identification of the different materials and determination of the composition of a biochip. The
lateral resolution required was achieved by using radiation from an infrared synchrotron beamline.
相似文献
16.
We quantitatively modeled the volume phase transition of a hydrogel containing a crystalline colloidal array with a crown
ether ligand which binds Pb2+. The hydrogel volume response and the wavelength diffracted depend on the Pb2+ concentration and on both the ionic strength and the valence of the nonbinding ionic species. We successfully modeled the
response of this hydrogel Pb2+ sensor to ionic strength and the cation valence of the added salts.
Figure Cation identity dependence of crown ether photonic crystal Pb+ sensing 相似文献
17.
Bertolini A Carelli G Francesconi F Francesconi M Marchesini L Marsili P Sorrentino F Cristoforetti G Legnaioli S Palleschi V Pardini L Salvetti A 《Analytical and bioanalytical chemistry》2006,385(2):240-247
Laser-induced breakdown spectroscopy (LIBS) is a promising technique for in situ elemental analysis. A new mobile instrument
for LIBS analysis, developed in a collaboration between Marwan Technology s.r.l. and the Applied Laser Spectroscopy Laboratory
in Pisa, is presented, and some applications of it and results from it are outlined. The innovative experimental set-up, based
on the use of two suitably retarded laser pulses and a standardless analysis procedure, which overcomes problems related to
matrix effects, greatly improves the potential of this technique for accurate quantitative analysis.
相似文献
18.
Sum-frequency generation (SFG) is a nonlinear laser-spectroscopy technique suitable for analysis of adsorbed molecules. The
sub-monolayer sensitivity of SFG spectroscopy enables vibrational spectra to be obtained with high specificity for a variety
of molecules on a range of surfaces, including metals, oxides, and semiconductors. The use of ultra-short laser pulses on
time-scales of picoseconds also makes time-resolved measurements possible; this can reveal ultrafast transient changes in
molecular arrangements. This article reviews recent time-resolved SFG spectroscopy studies revealing site-hopping of adsorbed
CO on metal surfaces and the dynamics of energy relaxation at water/metal interfaces.
Time-resolved sum frequency generation spectroscopy at surfaces with non-resonant laser pulse irradiation 相似文献
19.
Fluoroquinolones in soil—risks and challenges 总被引:5,自引:0,他引:5
Fluoroquinolones (FQs) are among the most important antibacterial agents used in human and veterinary medicine. Because of
the growing practice of adding manure and sewage sludge to agricultural fields these drugs end up in soils, where they can
accumulate and have adverse effects on organisms. This paper presents an overview of recent developments in the determination
of FQs in solid environmental matrices and describes the risks and challenges (persistence, fate, effects, and remediation)
which result from their presence in soil.
Figure Pathways into the environment for FQs 相似文献
20.
A novel quartz device has been designed to trap arsine and selenium hydride and subsequently to volatilize the collected analyte
and atomize it for atomic-absorption spectrometric detection. The device is actually the multiple microflame quartz-tube atomizer
(multiatomizer) with inlet arm modified to serve as the trap and to accommodate the oxygen-delivery capillary used to combust
hydrogen during the trapping step. The effect of relevant experimental conditions (trap temperature during trapping and hydrogen
flow rate and trap temperature during volatilization) on collection and volatilization efficiency was investigated. Under
the optimum conditions collection and volatilization efficiency for arsenic and selenium were 50 and 70%, respectively.
相似文献