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1.
Detection of oncoprotein platelet-derived growth factor using a fluorescent signaling complex of an aptamer and TOTO 总被引:1,自引:0,他引:1
There have recently been advances in the application of aptamers, a new class of nucleic acids that bind specifically with
target proteins, as protein recognition probes for biomedical study. The development of a signaling aptamer with the capability
of simple and rapid real-time detection of disease-related proteins has attracted increasing interest. We have recently reported
a new protein-detection strategy using a signaling aptamer based on a DNA molecular light-switching complex, [Ru(phen)2(dppz)]2+. In this work we have used the commercially available DNA-intercalating dye, TOTO, to replace [Ru(phen)2(dppz)]2+ for detection of oncoprotein platelet-derived growth factor BB (PDGF-BB), a potential cancer marker. Taking advantage of
the high affinity of the aptamer to PDGF-BB and the sensitive fluorescence change of the aptamer–TOTO signaling complex on
protein binding, PDGF-BB was detected in physiological buffer with high selectivity and sensitivity. The detection limit was
0.1 nmol L−1, which was better than that of other reported aptamer-based methods for PDGF-BB, including that using [Ru(phen)2(dppz)]2+. The method is very simple with no need for covalent labeling of the aptamer or probe synthesis. It facilitates wide application
of the signaling mechanism to the analysis and study of cancer markers and other proteins.
相似文献
2.
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
3.
Monterola MP Smith BW Omenetto N Winefordner JD 《Analytical and bioanalytical chemistry》2008,391(7):2617-2626
A simple, fast, reliable, sensitive and potentially portable explosive detection device was developed employing laser photofragmentation
(PF) followed by heterogeneous chemiluminescence (CL) detection. The PF process involves the release of NOx(x = 1,2) moieties from explosive compounds such as TNT, RDX, and PETN through a stepwise excitation–dissociation process using a 193 nm
ArF laser. The NOx(x = 1,2) produced upon PF is subsequently detected by its CL reaction with basic luminol solution. The intensity of the CL signal
was detected by a thermoelectrically cooled photomultiplier tube with high quantum efficiency and negligible dark current
counts. The system was able to detect trace amounts of explosives in various forms in real time under ambient conditions.
Detection limits of 3 ppbv for PETN, 2 ppbv for RDX, and 34 ppbv for TNT were obtained. It was also demonstrated that the
presence of PETN residue within the range of 61 to 186 ng/cm2 can be detected at a given signal-to-background ratio of 10 using a few microjoules of laser energy. The technique also demonstrated
its potential for the direct analysis of trace explosive in soil. An LOD range of 0.5–4.3 ppm for PETN was established, which
is comparable to currently available techniques.
Figure Photofragmentation–chemiluminescence detector 相似文献
4.
A highly selective and sensitive chemiluminescence method for the determination of triclosan is proposed. The method is based
on the phototransformation of triclosan to a light-emitting precursor in the presence of fluorescein in alkaline medium and
the chemiluminescence reaction is then triggered by strong base or oxidants such as N-bromosuccinimide. Based on this reaction an online phototransformation–flow injection manifold was developed, in which the
photoreactor comprises a 150-cm-long × 0.8-mm-i.d. piece of PTFE tubing coiled around a 25-W fluorescent lamp, and the phototransformed
products were then injected into a carrier stream of borate buffer. After mixing with the oxidant stream the produced light
was detected by a photomultiplier. A wide calibration range from 8.0 × 10−8 to 1.0 × 10−4 mol L−1 was obtained under the optimized conditions, and the detection limit was as low as 5.0 × 10−8 mol L−1. The whole process of analysis, including the online phototransformation and subsequent chemiluminescence detection, could
be completed in 6 min. Most of the foreign substances tested showed high tolerance levels, and the proposed method was directly
applied to the determination of triclosan in toothpaste samples without any pre-separation procedure.
Figure Schematic representation of the phototransformation of triclosan and subsequent chemiluminescence reaction 相似文献
5.
Enzyme-linked immunosorbent assay (ELISA), horseradish peroxidase (HRP)-catalyzed fluorescent reaction, and oxalate chemiluminescence
imaging analysis have been combined to develop a sensitive, simple, and rapid method for analysis of interferon alpha (α-IFN)
in human serum samples. A typical “sandwich type” immunoassay was used. Reaction of o-phenylenediamine (OPD) with hydrogen peroxide (H2O2), catalyzed by HRP, produced 2,3-diaminophenazine (PDA), which was detected by chemiluminescence imaging analysis with the
bis(2,4,6-trichlorophenyl)oxalate (TCPO)–H2O2–glyoxaline–PDA chemiluminescent system. The TCPO chemiluminescent imaging system is more sensitive and the chemiluminescence
quantum yield is at least five times higher than for the luminol–H2O2–HRP–PIP (p-iodophenol) chemiluminescent imaging system. The results showed there was a very good linear correlation between response
and amount of α-IFN in the range 1.3–156.0 pg mL−1 (R = 0.9991) and the detection limit was 0.8 pg mL−1 (S/N=3). The relative standard deviation (n = 9) was 4.7%. The proposed method has been used for successful analysis of the amount of α-IFN in human serum. The results
obtained compared well with those obtained by conventional colorimetric ELISA and luminol chemiluminescent ELISA.
Figure Procedures of the proposed method 相似文献
6.
Amatatongchai M Hofmann O Nacapricha D Chailapakul O deMello AJ 《Analytical and bioanalytical chemistry》2007,387(1):277-285
A microfluidic system incorporating chemiluminescence detection is reported as a new tool for measuring antioxidant capacity.
The detection is based on a peroxyoxalate chemiluminescence (PO-CL) assay with 9,10-bis-(phenylethynyl)anthracene (BPEA) as
the fluorescent probe and hydrogen peroxide as the oxidant. Antioxidant plugs injected into the hydrogen peroxide stream result
in inhibition of the CL emission which can be quantified and correlated with antioxidant capacity. The PO-CL assay is performed
in 800-μm-wide and 800-μm-deep microchannels on a poly(dimethylsiloxane) (PDMS) microchip. Controlled injection of the antioxidant
plugs is performed through an injection valve. Of the plant-food based antioxidants tested, β-carotene was found to be the
most efficient hydrogen peroxide scavenger (SA
HP of 3.27 × 10−3 μmol−1 L), followed by α-tocopherol (SA
HP of 2.36 × 10−3 μmol−1 L) and quercetin (SA
HP of 0.31 × 10−3 μmol−1 L). Although the method is inherently simple and rapid, excellent analytical performance is afforded in terms of sensitivity,
dynamic range, and precision, with RSD values typically below 1.5%. We expect our microfluidic devices to be used for in-the-field
antioxidant capacity screening of plant-sourced food and pharmaceutical supplements.
Figure Assembled PDMS microchip sandwiched between two glass plates with the top plate containing capillary reservoirs 相似文献
7.
Wang Z Wilkop T Xu D Dong Y Ma G Cheng Q 《Analytical and bioanalytical chemistry》2007,389(3):819-825
We report on the use of PDMS multichannels for affinity studies of DNA aptamer–human Immunoglobulin E (IgE) interactions by
surface plasmon resonance imaging (SPRi). The sensing surface was prepared with thiol-terminated aptamers through a self-assembling
process in the PDMS channels defined on a gold substrate. Cysteamine was codeposited with the thiol aptamers to promote proper
spatial arrangement of the aptamers and thus maintain their optimal binding efficiencies. Four aptamers with different nucleic
acid sequences were studied to test their interaction affinity toward IgE, and the results confirmed that aptamer I (5′-SH-GGG
GCA CGT TTA TCC GTC CCT CCT AGT GGC GTG CCC C-3′) has the strongest binding affinity. Control experiments were conducted with
a PEG-functionalized surface and IgG was used to replace IgE in order to verify the selective binding of aptamer I to the
IgE molecules. A linear concentration-dependent relationship between IgE and aptamer I was obtained, and a 2-nM detection
limit was achieved. SPRi data were further analyzed by global fitting, and the dissociation constant of aptamer I–IgE complex
was found to be 2.7 × 10−7 M, which agrees relatively well with the values reported in the literature. Aptamer affinity screening by SPR imaging demonstrates
marked advantages over competing methods because it does not require labeling, can be used in real-time, and is potentially
high-throughput. The ability to provide both qualitative and quantitative results on a multichannel chip further establishes
SPRi as a powerful tool for the study of biological interactions in a multiplexed format.
Figure The SPRi sensograms and thier global fits for aptamer I and IgE interactions. Insert in the difference image obtained with
the PDMS microchannel flow cell for aptamer IV, III, and I (from left to right 相似文献
8.
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
9.
Baek TJ Park PY Han KN Kwon HT Seong GH 《Analytical and bioanalytical chemistry》2008,390(5):1373-1378
We describe a DNA microarray system using a bipolar integrated circuit photodiode array (PDA) chip as a new platform for DNA
analysis. The PDA chip comprises an 8 × 6 array of photodiodes each with a diameter of 600 μm. Each photodiode element acts
both as a support for an immobilizing probe DNA and as a two-dimensional photodetector. The usefulness of the PDA microarray
platform is demonstrated by the detection of high-risk subtypes of human papilloma virus (HPV). The polymerase chain reaction
(PCR)-amplified biotinylated HPV target DNA was hybridized with the immobilized probe DNA on the photodiode surface, and the
chip was incubated in an anti-biotin antibody-conjugated gold nanoparticle solution. The silver enhancement by the gold nanoparticles
bound to the biotin of the HPV target DNA precipitates silver metal particles at the chip surfaces, which block light irradiated
from above. The resulting drop in output voltage depends on the amount of target DNA present in the sample solution, which
allows the specific detection and the quantitative analysis of the complementary target DNA. The PDA chip showed high relative
signal ratios of HPV probe DNA hybridized with complementary target DNA, indicating an excellent capability in discriminating
HPV subtypes. The detection limit for the HPV target DNA analysis improved from 1.2 nM to 30 pM by changing the silver development
time from 5 to 10 min. Moreover, the enhanced silver development promoted by the gold nanoparticles could be applied to a
broader range of target DNA concentration by controlling the silver development time.
Figure An optical image of the PDA chip and target DNA detection through silver enhancement
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
10.
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
11.
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
12.
Maria Chiara Pietrogrande Dimitri Bacco Mattia Mercuriali 《Analytical and bioanalytical chemistry》2010,396(2):877-885
This paper describes methods for the determination of low-molecular-weight (LMW) dicarboxylic acids in atmospheric aerosols
as important chemical tracers for source apportionment of aerosol organics and for studying atmospheric processes leading
to secondary organic aerosol formation. The two derivatization procedures most widely used in GC analysis of dicarboxylic
acids were compared: esterification using BF3/alcohol reagent and silylation using N,O-bis(trimethylsilyl)-trifluoroacetamide (BSTFA). The advantages and drawbacks of the two methods are investigated and compared
in terms of (1) precision and accuracy of the results and (2) sensitivity and detection limit of the procedure. The comparative
investigation was performed on standard solutions containing target C3–C9 dicarboxylic acids and on experimental particulate matter (PM) samples. Attention was focused on low-volume sampling devices
that collect small amounts of sample for organic speciation. The results show that, overall, both the techniques appear suitable
for the analysis of LMW dicarboxylic acids in atmospheric aerosols since they provide low detection limits (≤4 ng m−3) and satisfactory reproducibility (RSD% ≤ 15%). Between them, BSTFA should be the reagent of choice under the most limiting
conditions of PM filters collected by low-volume air samplers: It provides determination of all the target C3–C9 dicarboxylic acids with lower detection limits (≤2 ng m−3) and higher reproducibility (RSD% ≤ 10%)
相似文献
13.
Xaver Y. Z. Karsunke Reinhard Niessner Michael Seidel 《Analytical and bioanalytical chemistry》2009,395(6):1623-1630
Pathogen detection is important for health and safety reasons. Several outbreaks all over the world have shown the need for
rapid, qualitative, quantitative, and, particularly, multianalyte detection systems. Hence, a multichannel flow-through chemiluminescence
microarray chip for parallel detection of pathogenic bacteria was developed. The disposable chip made of acrylonitrile–butadiene–styrene
(ABS) copolymer was devised as a support for a multiplexed sandwich immunoassay. Calibration and measurement was possible
in one experiment, because the developed chip contains six parallel flow-through microchannels. Polyclonal antibodies against
the pathogenic bacteria Escherichia coli O157:H7, Salmonella typhimurium, and Legionella pneumophila were immobilized on the chip by microcontact printing in order to use them as specific receptors. Detection of the captured
bacteria was carried out by use of specific detection antibodies labelled with biotin and horseradish peroxidase (HRP)–streptavidine
conjugates. The enzyme HRP generates chemiluminescence after adding luminol and hydrogen peroxide. This signal was observed
by use of a sensitive CCD camera. The limits of detection are 1.8 × 104 cells mL−1 for E. coli O157:H7, 7.9 × 104 cells mL−1 for L. pneumophila, and 2.0 × 107 cells mL−1 for S. typhimurium. The overall assay time for measurement and calibration is 18 min, enabling very fast analysis.
相似文献
14.
Fast and sensitive DNA analysis using changes in the FRET signals of molecular beacons in a PDMS microfluidic channel 总被引:3,自引:0,他引:3
Jung J Chen L Lee S Kim S Seong GH Choo J Lee EK Oh CH Lee S 《Analytical and bioanalytical chemistry》2007,387(8):2609-2615
A new DNA hybridization analytical method using a microfluidic channel and a molecular beacon-based probe (MB-probe) is described.
A stem-loop DNA oligonucleotide labeled with two fluorophores at the 5′ and 3′ termini (a donor dye, TET, and an acceptor
dye, TAMRA, respectively) was used to carry out a fast and sensitive DNA analysis. The MB-probe utilized the specificity and
selectivity of the DNA hairpin-type probe DNA to detect a specific target DNA of interest. The quenching of the fluorescence
resonance energy transfer (FRET) signal between the two fluorophores, caused by the sequence-specific hybridization of the
MB-probe and the target DNA, was used to detect a DNA hybridization reaction in a poly(dimethylsiloxane) (PDMS) microfluidic
channel. The azoospermia gene, DYS 209, was used as the target DNA to demonstrate the applicability of the method. A simple
syringe pumping system was used for quick and accurate analysis. The laminar flow along the channel could be easily controlled
by the 3-D channel structure and flow speed. By injecting the MB-probe and target DNA solutions into a zigzag-shaped PDMS
microfluidic channel, it was possible to detect their sequence-specific hybridization. Surface-enhanced Raman spectroscopy
(SERS) was also used to provide complementary evidence of the DNA hybridization. Our data show that this technique is a promising
real-time detection method for label-free DNA targets in the solution phase.
Figure FRET-based DNA hybridization detection using a molecular beacon in a zigzag-shaped PDMS microfluidic channel 相似文献
15.
Gil García MD Martínez Galera M Santiago Valverde R 《Analytical and bioanalytical chemistry》2007,387(6):1973-1981
The viability of tandem photochemical reaction–chemiluminescence detection has been studied for the determination of five
benzoylurea insecticides, namely, diflubenzuron, triflumuron, hexaflumuron, lufenuron and flufenoxuron. The ‘on-line’ photochemical
reaction of benzoylurea pesticides provides an enhanced chemiluminescence response of the pesticides during their oxidation
by potassium hexacyanoferrate(III) and sodium hydroxide, whose signal increases with the percentage of acetonitrile in the
reaction medium. The determination was performed using a photoreactor consisting of a PFA (perfluoroalkoxy) tube reactor coil
(5 m × 1.6-mm O.D. and 0.8-mm I.D.) and an 8-W xenon lamp. As the yield of the photoderivatization process and the chemiluminescent
signals depend on the percentage of acetonitrile, the chromatographic column (a Gemini C18, Phenomenex 150 mm × 4.6 mm, 5-μm
particle size) was chosen with the aim of using high percentages of this organic solvent in the mobile phase. Previous studies
showed that the rate of the chemiluminescent reaction was very fast. Therefore, a modification was carried out in the detector
in order to mix the analytes and reactants as near as possible to the measure cell. The optimised method was validated with
respect to linearity, precision, limits of detection and quantification accuracy. Under the optimised conditions, linear working
range extends three orders of magnitude with the relative standard deviation of intra-day precision below 10% and detection
limits between 0.012 and 0.18 μg mL−1, according to the compound. The proposed method has been successfully applied to the determination of benzoylureas in cucumber
with good results.
Figure 相似文献
16.
We screened a series of RNA and DNA aptamers for their ability to serve in the dye displacement assays in which analytes compete
with TO dye. We conclude that, while the performance of the TO dye displacement approach is not always predictable, it is
still a simple and sensitive assay to detect binding between RNA aptamers and small molecules. In particular, we describe
efficient assays for tobramycin and theophylline, with up to 90% displacement of TO observed, and we describe the first aptameric
assay for cAMP.
Figure An RNA or DNA aptamer against a molecule (circle) binds TO dye, resulting in a fluorescent complex. Presence of free molecule in solution results in the displacement of TO
from the complex and a reduction in fluorescence
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
17.
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
18.
Catechol determination in compost bioremediation using a laccase sensor and artificial neural networks 总被引:1,自引:0,他引:1
Tang L Zeng G Liu J Xu X Zhang Y Shen G Li Y Liu C 《Analytical and bioanalytical chemistry》2008,391(2):679-685
An electrochemical biosensor based on the immobilization of laccase on magnetic core-shell (Fe3O4–SiO2) nanoparticles was combined with artificial neural networks (ANNs) for the determination of catechol concentration in compost
bioremediation of municipal solid waste. The immobilization matrix provided a good microenvironment for retaining laccase
bioactivity, and the combination with ANNs offered a good chemometric tool for data analysis in respect to the dynamic, nonlinear,
and uncertain characteristics of the complex composting system. Catechol concentrations in compost samples were determined
by using both the laccase sensor and HPLC for calibration. The detection range varied from 7.5 × 10–7 to 4.4 × 10–4 M, and the amperometric response current reached 95% of the steady-state current within about 70 s. The performance of the
ANN model was compared with the linear regression model in respect to simulation accuracy, adaptability to uncertainty, etc.
All the results showed that the combination of amperometric enzyme sensor and artificial neural networks was a rapid, sensitive,
and robust method in the quantitative study of the composting system.
Figure Structure of the magnetic carbon paste electrode used in the electrochemical biosensor 相似文献
19.
A novel method for the future development of label-free DNA sensors is proposed here. The approach is based on the displacement
of a labelled suboptimum mutated oligonucleotide hybridised with the immobilised biotin-capture probe. The target fully complementary
to the biotin-capture probe can displace the labelled oligonucleotide causing a subsequent decrease of the signal that verifies
the presence of the target. The decrease of signal was demonstrated to be proportional to the target concentration. A study
of the hybridisation of mutated and complementary labelled oligonucleotides with an immobilised biotin-capture probe was carried
out. Different kinetic and thermodynamic behaviour was observed for heterogeneous hybridisation of biotin-capture probe with
complementary or suboptimum oligonucleotides. The displacement method evaluated colourimetrically achieved the objective of
decreasing the response time from 1 h for direct hybridisation of 19-mer oligonucleotides in the direct enzyme-linked oligonucleotide
assay (ELONA) to 5 min in the case of displacement detection in the micromolar concentration range.
Figure The detection system is based on the displacement of suboptimum HRP-labelled mutated oligonucleotide by the fully complementary
target 相似文献
20.
A performant reagentless electrochemiluminescent (ECL) detection system for H2O2 is presented, based on an electropolymerized polyluminol film prepared under near-neutral conditions. Such an original polyluminol
electrodeposition is reported for the first time and on a screen-printed electrode (SPE) surface. Electropolymerized luminol
acts as an active luminophore of the electrochemiluminescent reaction, as the monomer does. Polymerization conditions have
been optimized in order to obtain the best ECL responses to H2O2. By performing electrodeposition in a potentiostatic mode, at 425 mV vs. Ag|AgCl, in 0.1 mol L−1 phosphate/0.1 mol L−1 KCl pH 6 and 1 mmol L−1 luminol, with a total charge of 0.5 mC, the linear range for H2O2 detection extends from 7.9 × 10−8 mol L−1 to 1.3 × 10−3 mol L−1. Such performant disposable reagentless easy-to-use miniaturized systems based on SPEs should be applicable to the electrochemiluminescent
detection of many oxidase-substrate compounds.
Figure An original polyluminol electrodeposition process on a screen-printed electrode surface is reported for the first time. The
polymeric structure is demonstrated to behave as an electrochemiluminescent luminophore, allowing disposable reagentless easy-to-use
optical sensors for hydrogen peroxide detection to be designed. 相似文献