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1.
Hansen JA Wang J Kawde AN Xiang Y Gothelf KV Collins G 《Journal of the American Chemical Society》2006,128(7):2228-2229
The coupling of aptamers with the coding and amplification features of inorganic nanocrystals is shown for the first time to offer a highly sensitive and selective simultaneous bioelectronic detection of several protein targets. This is accomplished in a single-step displacement assay in connection to a self-assembled monolayer of several thiolated aptamers conjugated to proteins carrying different inorganic nanocrystals. Electrochemical stripping detection of the nondisplaced nanocrystal tracers results in a remarkably low (attomole) detection limit, that is, significantly lower than those of existing aptamer biosensors. The new device offers great promise for measuring a large panel of disease markers present at ultralow levels during early stages of the disease progress. 相似文献
2.
Svatos A Antonchick A Schneider B 《Rapid communications in mass spectrometry : RCM》2004,18(7):816-821
A selective and sensitive electrospray ionization (ESI) mass spectrometry based method for detection of brassinosteroids (BS) in plant samples was developed. The limit of detection (LOD) was dramatically reduced over existing analytical methods using a microbore (1.00 mm) C18 column and chemical derivatization of free BS to dansyl-3-aminophenylboronates. The LOD in the selected-ion monitoring (SIM) mode for derivatized BS was 125 attomole (signal-to-noise ratio 3). The practical utility of the method is documented in Arabidopsis thaliana plant transformation of castasterone to brassinolide using a deuterium-labeled precursor. The method could be very useful for the detection of native BS in plant tissue and biosynthetic studies. 相似文献
3.
高效毛细管电泳电化学检测器的研制 总被引:7,自引:0,他引:7
本文提出了一种用于高效毛细管电泳的新型安培电化学检测器设计,使用Nafion溶液制作的HPCE/ED接口,可有效地隔开两化学系统的干扰,且不引入附加体积,经对有机酚类化合物的胶束电动毛细管色谱分离与电化学检测知,该系统性能优良,对对苯二酚的检出限为30amol。 相似文献
4.
Summary A detection scheme based upon peroxyoxalate chemiluminescence, which utilizes two post-column pumps and two stages of depressurization is investigated. The chemiluminescent detection limit for perylene is 23 times lower than determined by fluorescence, and is in the attomole range. This detection technique is investigated for packed column supercritical fluid chromatography (SFC). Due to the interface design used and the chemical band narrowing effects of chemiluminescence, an apparent increase in efficiency is observed. The interface design affords a wide range of pressures to be used for a separation. During pressure programming the column effluent changes flow rate. Because of a back-pressure regulator, the reaction and detection take place at nearly constant pressure. Therefore pressure gradient work is possible without concern for post-column reagent solubility (which is a concern for high-performance liquid chromatography). The effects of the expanded CO2 from the SFC on the chemiluminescence signal and background are studied. The post-column detection is optimized for pH, photomultiplier voltage, concentrations and flow rates of the peroxide and oxalate ester. 相似文献
5.
Wenxin Zhu Jinrun Dong Guoxiang Ruan Yuan Zhou Prof. Jiandong Feng 《Angewandte Chemie (International ed. in English)》2023,62(7):e202214419
A single-molecule electrochemiluminescence bioassay is developed here which allows imaging and direct quantification of single biomolecules. Imaging single biomolecules is realized by localizing the electrochemiluminescence events of the labeled molecules. Such an imaging system allows mapping the spatial distribution of biomolecules with electrochemiluminescence and contains quantitative single-molecule insights. We further quantify biomolecules by spatiotemporally merging the repeated reactions at one molecule site and then counting the clustered molecules. The proposed single-molecule electrochemiluminescence bioassay is used to detect carcinoembryonic antigen, showing a limit of detection of 67 attomole concentration which is 10 000 times better than conventional electrochemiluminescence bioassays. This spatial resolution and sensitivity enable single-molecule electrochemiluminescence bioassay a new toolbox for both specific bioimaging and ultrasensitive quantitative analysis. 相似文献
6.
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
7.
Aryl oxalate chemiluminescence detection for high-performance liquid chromatography offers ultrahigh sensitivity for interactive fluorophores. With optimal analytes, attomole limits of detection can be obtained with conventional instrumentation 相似文献
8.
Lazar AC Reilly PT Whitten WB Ramsey JM 《Rapid communications in mass spectrometry : RCM》2000,14(16):1523-1529
Aerosol mass spectrometry with laser desorption/ionization was investigated as a possible tool for real-time monitoring of the presence of the pesticide paraquat on the surface of airborne soil particles. Laser desorption/ionization of paraquat dication produced only singly charged ions. The most abundant species were [M](+.), [M - H](+), and [M - CH3](+). Operation of the ion trap mass spectrometer in the MS(3) mode allowed the reduction of the signal dependence on laser fluence fluctuations and permitted the detection of the analyte with good sensitivity and high selectivity. The estimated limit of detection in terms of surface coverage was 0.016 monolayers, approximately 1 attomole of paraquat on the surface of a single micron-sized soil particle. 相似文献
9.
Glucose is directly related to brain activity and to diabetes.Therefore,developing a rapid and sensitive method for glucose detection is essential.Here,label-free glucose detection at attomole levels was realized by detecting the average diameter change of gold nanoparticles(AuNPs)utilizing dynamic light scattering(DLS).Single-strand DNA(ssDNA)adsorbed into the AuNPs’surfaces and prevented them from aggregating in solution that contained NaCl.However,ssDNA cleaved onto ssDNA fragments upon addition of glucose,and these fragments could not adsorb onto the AuNPs’surfaces.Therefore,in high-salt solution,AuNPs would aggregate and their average diameter would increase.Based on monitoring the average diameter of AuNPs with DLS,glucose could be detected in the range from 15 pmol/L to 2.0 nmol/L,with a detection limit of 8.3 pmol/L.Satisfactory results were also obtained when the proposed method was applied in human serum glucose detection. 相似文献
10.
In this research a novel nickel complex was used as electrocatalyst for electrooxidation of glycine. A nano-structured nickel chelidamic acid was electrodeposited on a bimetallic Au-Pt inorganic-organic hybrid nanocomposite modified electrode. The electrode possesses a three-dimensional (3D) porous network nanoarchitecture, in which the bimetallic Au-Pt NPs serving as metal nanoparticle based microelectrode ensembles are distributed in the matrix of interlaced 3,3′,5,5′-tetramethylbenzidine (TMB) organic nanofibers (NFs). Electrocatalytic oxidation of glycine on the surface of modified electrode was investigated with cyclic voltammetry method and the results showed that the nickel chelidamic acid films displayed excellent electrochemical catalytic activities towards glycine oxidation. The hydrodynamic amperometry at rotating modified electrode at constant potential versus reference electrode was used for detection of glycine. Under optimized conditions the calibration plots are linear in the concentration range 1 μM-0.75 mM and detection limit was found to be 0.3 μM. 相似文献
11.
Microchip capillary electrophoresis (μCE) with amperometric detection at Cu electrode benefited fast separation and direct detection of carbohydrates. The working electrode of 50-μm Cu wire attached nearly against the channel outlet—4 μm, where it benefited collecting detection current and suppressing overwhelming noise. The use of alkaline medium was essential to separating and detecting carbohydrates, which dissociated into the sensitive alcolate anions. The 10-cm serpentine chip, though lengthening the migration time, it provided better efficiency. Sucrose, cellobiose, glucose, and fructose migrated from the outlet in 400 s +2000 V. The linear calibration plots ranging from 10 to 1000 μM with regression coefficients better than 0.996 were obtained. The injection-to-injection reproducibility of 1.24% (n=7) for glucose in peak current and 0.6% for migration times were excellent. The detection limit was low, down to 2.3 μM for glucose (S/N=3) or 27.6 attomole in mass detection. 相似文献
12.
Gadolinium oxide: Exclusive selectivity and sensitivity in the enrichment of phosphorylated biomolecules
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Fahmida Jabeen Muhammad Najam‐ul‐Haq Muhammad Naeem Ashiq Matthias Rainer Christian W. Huck Guenther K. Bonn 《Journal of separation science》2016,39(21):4175-4182
Selectivity and sensitivity define the dynamic applicability of separation and enrichment techniques. Owing to proteome complexity, numbers of separation media have been introduced in phosphoproteomics. Complex samples are pretreated to make the low‐abundance molecules detectable by mass spectrometry. Gadolinium oxide nanoparticles, offering mono‐ and bi‐dentate interactions, are optimized to capture the phosphopeptides. Selectivity of 1:11 000 is achieved for digested β‐casein phosphopeptides in bovine serum albumin digest background using gadolinium oxide nanoparticles. The limit of detection goes down to 1 attomole. With the optimized sample preparation protocol, gadolinium oxide nanoparticles enrich phosphopeptides of κ‐casein (Ser148 and Ser170) from digested milk sample, fibrinogen alpha chain phosphopeptide (Ser609) along with four hydrolytic products of Ser22‐modified phosphopeptides from serum. 相似文献
13.
以3-对羟基苯甲酰喹啉-2-甲醛(CBQCA)为检测痕量氨基酸的柱前衍生试剂,利用高效液相色谱-激光诱导荧光-增强型电荷耦合器件检测器(HPLC-LIF-ICCD)系统,考察了氨基酸衍生和HPLC分离过程中多种因素的影响,建立了HPLC-LIF-ICCD分离检测痕量氨基酸的新方法,并应用于鼠脑微透析液的氨基酸检测.当信噪比为3时,对甘氨酸的质量检出限为5fmol. 相似文献
14.
A flow-injection system with an immobilized enzyme reactor is proposed for the determination of 3-hydroxybutyrate. 3-Hydroxybutyrate dehydrogenase is immobilized on aminated poly(vinyl alcohol) beads and packed into a stainless-steel column (4 cm x 4 mm I.D.). Serum is diluted and filtered. Sample solution (20 mul) is injected into the carrier stream [4mM NAD(+) in glycine buffer (pH 9.3)]. The NADH formed is detected at 465 nm (excitation at 340 nm). The calibration graph is linear for 0.7-500muM 3-hydroxybutyrate; the detection limit is 0.5muM. 相似文献
15.
16.
Shui W Yu Y Xu X Huang Z Xu G Yang P 《Rapid communications in mass spectrometry : RCM》2003,17(14):1541-1547
The physical processes underlying micro-electrospray (micro-ES) performance were investigated using a stainless steel (SS) emitter with a blunt tip. Sheathless micro-ES could be generated at a blunt SS tip without any tapering or sanding if ESI conditions were optimized. The Taylor cone was found to shrink around the inner diameter of the SS tubing, which permitted a low flow rate of 150 nL/min for sheathless microspray on the blunt tip (100 microm i.d. x 400 microm o.d.). It is believed that the wettability and/or hydrophobicity of SS tips are responsible for their micro-ES performance. The outlet orifice was further nipped to reduce the size of the spray cone and limit the flow rate to 50-150 nL/min, resulting in peptide detection down to attomole quantities consumed per spectrum. The SS emitter was also integrated into a polymethylmethacrylate microchip and demonstrated satisfactory performance in the analysis and identification of a myoglobin digest. 相似文献
17.
A method for determination of l-malate in wine is described. Malate dehydrogenase and oxaloacetate decarboxylase were immobilized on poly (vinyl alcohol) beads and incorporated in a flow-injection system with fluorescence detection. Sample solution (50 mul) was injected into the carrier stream [4mM NAD(+) in glycine buffer (pH 10.0)]. The fluorescence based on the NADH formed could be directly related to the amount of malate. The calibration graph was linear over the range 0.4-300muM. The detection limit was 0.2muM. Sampling throughout was 25 samples/hr. 相似文献
18.
Snežana S. Mitić Aleksandra N. Pavlović Snežana B. Tošić Biljana B. Arsić Slavica M. Sunarić 《Journal of Analytical Chemistry》2009,64(7):683-689
A kinetic method for the determination of nanogram quantities of amino acid glycine (Gly) is described. The catalytic activity
of cobalt in the reaction of oxidation of purpurin (1,2,4-trihydroxyantraquinone, PP) by hydrogen peroxide in alkaline buffer
solution decreases in the presence of micro quantities of glycine. Operating conditions for the successful determination of
glycine were optimized and yielded a theoretical detection limit of 6.5 ng/mL. Kinetic equations are proposed for the investigated
process. The interference effects of certain foreign ions and amino acids upon the reaction rate were studied in order to
assess the selectivity of the method. The procedure was successfully applied to the determination of glycine in various pharmaceutical
samples. The unique features of this procedure are that the determination can be carried out rapidly at room temperature and
analysis time is short. The procedure is simple, inexpensive and efficient for use in the analysis of a large number of samples.
The article is published in the original. 相似文献
19.
Conditions were selected for the separation of the herbicide glyphosate (N-(phosphonomethyl)glycine) and products of its microbiological utilization as N-acylated derivatives by ion-exchange liquid chromatography. The order of the elution of compounds on a Repro-Gel H column with UV detection correlates with their structures. The detection limits of the derivatives (wavelength 210 nm) are as follows (ng): glyphosate, 30; glycine and sarcosine, 20 and 43, respectively; aminomethylphosphonic acid, 45. The detection limit of methylphosphonic acid is 14 μg. Glyphosate and its biodegradation products were separated by thin-layer chromatography on plates with silica gel in the system isopropanol-5% aqueous ammonia solution (1: 1). 相似文献
20.
《中国化学快报》2021,32(10):3109-3112
A novel hydrogen-bonded organic frameworks (HOFs) FJU-200 has been constructed from N,N'-bis(5-isophthalic acid)naphthalimide (H4L). FJU-200 has a good dual-function of aniline and ultraviolet detection. FJU-200 is the first case of HOF with dual sensing of visual color changes and photoluminescence quenching for aniline detection, and the detection limit of aniline can reach 5.5 × 10−4 mol/L. Under ultraviolet FJU-200 will rapidly change from light yellow to rustic brown, which makes it possible to use FJU-200 to achieve minute-level ultraviolet detection. Moreover, for more convenient use, FJU-200 test papers are prepared. Using them, convenient and fast aniline or ultraviolet detection can be realized. The single-crystal X-ray structures show that compared with the original FJU-200, both PhNH2@FJU-200 and UV-FJU-200 have larger pore sizes, and the dihedral angles of the H2L2− in framework has been changed. 相似文献