Facet-dependent nonenzymatic glucose sensing properties of Cu2O cubes and octahedra

2016 ◽  
Vol 40 (8) ◽  
pp. 6573-6576 ◽  
Author(s):  
Linli Tang ◽  
Jian Lv ◽  
Chuncai Kong ◽  
Zhimao Yang ◽  
Jianhui Li
Keyword(s):  
Detection Limit ◽  
Modified Electrode ◽  
Glucose Sensing ◽  
Glucose Sensors ◽  
Linear Range ◽  
Sensing Properties ◽  
Lower Detection Limit ◽  
Lower Detection ◽  
Crystallographic Facets ◽  
Higher Sensitivity

Cu2O cubes and octahedra which have different crystallographic facets have been used for the nonenzymatic glucose sensors. A Cu2O octahedra modified electrode shows higher sensitivity, lower detection limit, and wider linear range than that of the cubes.

Preparation and Investigation of Toluene-Sensing Properties of Polymer/Inorganic Composite and Multi-Layer Films

2012 ◽  
Vol 531-532 ◽  
pp. 570-573
Author(s):  
Jian Liao ◽  
Guang Zhong Xie ◽  
Ya Dong Jiang ◽  
Tao Zhu ◽  
Wei Zhi Li ◽  
...  
Keyword(s):  
Composite Film ◽  
Recovery Time ◽  
Room Temperature ◽  
Film Sensor ◽  
Sensing Properties ◽  
Multi Wall Carbon Nanotubes ◽  
Lower Detection Limit ◽  
Toluene Vapor ◽  
Lower Detection ◽  
Higher Sensitivity

In this paper, poly 4-vinylphenol (P4VP)/multi-wall carbon nanotubes (MWNTs) composite film, P4VP/ carbon black (CB) composite film and P4VP/MWNTs multi-layer sensitive films prepared using airbrush technology were deposited on interdigitated electrodes to detect tolunene vapor at room temperature. The surface of the composite film was observed under a scanning electron microscope (SEM). It was found that the resistance of the sensor increased after the exposure to toluene vapor and the increased magnitude of the changes had a good linearity with concentrations of toluene. Meanwhile, the P4VP/MWNTs composite film sensor also has a higher sensitivity than P4VP/CB composite film sensor. P4VP/MWNTs three-layer film sensor was fabricated as well. It was estimated that the response time and recovery time of P4VP/MWNTs three-layer films sensor were about 15 s and 20 s, respectively. The sensor responses of S=0.12% at 10mg/m3 toluene vapor for P4VP/MWNTs three-layer films. The results showed that the multi-layer films sensor exhibited a lower detection limit and better sensing properties compared with the sensors based composite film.

A novel 3D Zn-coordination polymer based on a multiresponsive fluorescent sensor demonstrating outstanding sensitivities and selectivities for the efficient detection of multiple analytes

2021 ◽  
Author(s):  
Yu Liu ◽  
Yan Wang ◽  
Xiao-Sa Zhang ◽  
Yu-Shu Sheng ◽  
Wen-Ze Li ◽  
...  
Keyword(s):  
Detection Limit ◽  
Coordination Polymer ◽  
Fluorescent Sensor ◽  
Lower Detection Limit ◽  
Ph Values ◽  
Efficient Detection ◽  
Wide Range ◽  
Lower Detection ◽  
Multiple Analytes

A Zn-CP exhibits remarkable fluorescence behaviours and stability in a wide range of pH values. It can become an outstanding candidate in the selective sensing of Fe3+, Mg2+, Cr2O72−, MnO4−, NB and NM at a lower detection limit.

Manual Immunonephelometric Assay of Proteins, with Use of Polymer Enhancement

1974 ◽  
Vol 20 (9) ◽  
pp. 1181-1186 ◽  
Author(s):  
Jorge Lizana ◽  
Kristoffer Hellsing
Keyword(s):  
Detection Limit ◽  
Urinary Albumin ◽  
Optimal Time ◽  
Immunological Reaction ◽  
Reaction Conditions ◽  
Enhancing Effect ◽  
Lower Detection Limit ◽  
Small Series ◽  
Lower Detection ◽  
Immunonephelometric Assay

Abstract A manual immunonephelometric method for proteins has been developed by using an ordinary fluorometer as a nephelometer. By applying the enhancing effect of polyethylene glycol (av mol wt, 6000) on the immunological reaction, albumin and fibrinogen were quantitated after a 10-min reaction time. Under the present conditions the sensitivity was increased and thus antiserum consumption was decreased. The reaction conditions were carefully studied with respect to optimal time and concentration of the reactants. The precision of the method was 2.6-3.6% (CV). The lower detection limit in the albumin-antialbumin system was 0.1 mg/liter. Comparative studies showed a correlation coefficient of 0.991 with an automated immunonephelometric method for urinary albumin, and of 0.908 with a thrombin clottable method for plasma fibrinogen. We especially suggest use of this manual immunonephelometric method where small series of samples are to be analyzed.

New noncompetitive immunoassays of small analytes

1995 ◽  
Vol 41 (7) ◽  
pp. 986-990 ◽  
Author(s):  
U Piran ◽  
W J Riordan ◽  
L A Livshin
Keyword(s):  
Detection Limit ◽  
Liquid Phase ◽  
Binding Sites ◽  
Dynamic Range ◽  
Lower Detection Limit ◽  
Controlled Pore Glass ◽  
Lower Detection ◽  
Pore Glass ◽  
Clinically Significant ◽  
Acridinium Ester

Abstract We developed a novel noncompetitive immunoassay format for monoepitopic analytes and describe here a model assay for triiodothyronine (T3), performed on Ciba Corning's ACS:180 analyzer. Acridinium ester (AE)-labeled bivalent anti-T3 was incubated with the sample, producing AE-anti-T3/T3 complexes and unreacted AE-anti-T3. Controlled-pore glass particles (CPG) with immobilized diiodothyronine (T2) were then added in excess, to bind AE-anti-T3 possessing two unoccupied binding sites but not AE-anti-T3 bound to one or two T3 molecules. Paramagnetic particles (PMP) with immobilized anti-AE were then added to the same cuvette to capture AE-anti-T3/T3 complexes; AE-anti-T3 bound to the surface of CPG, however, was not captured, because of steric hindrance. After the incubation, the PMP was magnetically separated to remove the liquid phase and the suspended CPG from the cuvette. The chemiluminescence associate with the PMP remaining in the cuvette was then measured. This noncompetitive T3 assay exhibited a 10-fold lower detection limit than the equivalent competitive T3 assay, i.e., 0.3 vs pg/test. Imprecision (CV) in the clinically significant range was 6% or less. The assay also displayed two- to sevenfold lower cross-reactivities and a wider dynamic range.

Highly Sensitive Paper-Disc Assays for Detecting Penicillin in Milk

1985 ◽  
Vol 48 (1) ◽  
pp. 16-20 ◽  
Author(s):  
GINA M. BALBI ◽  
PAUL A. HARTMAN
Keyword(s):  
Detection Limit ◽  
Starter Cultures ◽  
Biologically Active ◽  
Penicillin G ◽  
Lower Detection Limit ◽  
Critical Concentrations ◽  
Plate Assay ◽  
Lower Detection ◽  
Standard Assay ◽  
Dairy Starter Cultures

A modified Bacillus subtilis disc-plate assay could detect 0.015 I.U. of penicillin G per ml of milk, whereas the lower detection limit of the standard assay was 0.050 I.U. per ml. Likewise, a modified Bacillus stearothermophilus disc-plate assay could detect 0.003 I.U. of penicillin G per ml of milk, whereas the lower detection limit of the standard assay was 0.005 I.U. per ml. Increased sensitivities were accomplished by preloading assay discs with “critical” concentrations so that minute quantities of antibiotic above the “critical” concentrations would produce zones of inhibition. Only a few alterations in routine laboratory procedure were required to perform the assays. Use of these assays should assure a milk supply that would not cause allergic reactions in humans or significantly inhibit dairy starter cultures. The general principal of “critical” concentration might have applications other than those that we have described, to increase the sensitivity of radial-diffusion analyses for biologically active compounds.

Improved Spectrophotometric Determination of Cyclopiazonic Acid in Poultry Feed and Corn

1990 ◽  
Vol 73 (2) ◽  
pp. 257-259 ◽  
Author(s):  
Ivan Chang-Yen ◽  
Keshore Bidasee
Keyword(s):  
Detection Limit ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Cyclopiazonic Acid ◽  
Poultry Feed ◽  
Reaction Conditions ◽  
Lower Detection Limit ◽  
Lower Detection ◽  
Feed Samples

Abstract An improved visible spectrophotometric method has been developed for cyclopiazonic acid in poultry feed and corn. The method Is based on the reaction of cyclopiazonic acid with Ehrlich reagent and detection at 580 nm. Reaction conditions were optimized with respect to reaction and measurement times and acid and Ehrlich reagent concentrations. Calibration curves were linear from 1 to 20 μg cyclopiazonic acid in 3 mL Ehrlich reagent, with a lower detection limit of 0.08 mg/kg for 50 g samples of poultry feed and corn. Recoveries from 50 g samples of poultry feed spiked with cyclopiazonic ranging from 0.16 to 1.20 mg/kg averaged 93.8%. Moldy corn and poultry feed samples analyzed by this method contained between 1 and 4 mg/kg cyclopiazonic acid.

scholarly journals Orthogonal Demodulation Pound–Drever–Hall Technique for Ultra-Low Detection Limit Pressure Sensing

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3223 ◽  
Author(s):  
Jinliang Hu ◽  
Sheng Liu ◽  
Xiang Wu ◽  
Liying Liu ◽  
Lei Xu
Keyword(s):  
Detection Limit ◽  
Detection Method ◽  
Wavelength Shift ◽  
Pressure Sensing ◽  
Frequency Sensitivity ◽  
Lower Detection Limit ◽  
Lower Detection ◽  
Shift Detection ◽  
Quality Factor Q ◽  
Hall Technique

We report on a novel optical microcavity sensing scheme by using the orthogonal demodulation Pound–Drever–Hall (PDH) technique. We found that larger sensitivity in a broad range of cavity quality factor (Q) could be obtained. Taking microbubble resonator (MBR) pressure sensing as an example, a lower detection limit than the conventional wavelength shift detection method was achieved. When the MBR cavity Q is about 105–106, the technique can decrease the detection limit by one or two orders of magnitude. The pressure-frequency sensitivity is 11.6 GHz/bar at wavelength of 850 nm, and its detection limit can approach 0.0515 mbar. This technique can also be applied to other kinds of microcavity sensors to improve sensing performance.

scholarly journals Rapid Assay of Trace Immunoglobulin M by a New Immunonanogold Resonance Scattering Spectral Probe

2008 ◽  
Vol 13 (4) ◽  
pp. 302-308 ◽  
Author(s):  
Zhiliang Jiang ◽  
Lili Wei ◽  
Mingjing Zou ◽  
Aihui Liang ◽  
Mianwu Meng
Keyword(s):  
Polyethylene Glycol ◽  
Detection Limit ◽  
Resonance Scattering ◽  
Immunoglobulin M ◽  
Serum Samples ◽  
Rapid Assay ◽  
Lower Detection Limit ◽  
Lower Detection ◽  
Polyethylene Glycol 6000

Nanogold, 8 nm in size, was used to label goat antihuman immunoglobulin M (GIgM) to obtain a new immunonanogold resonance scattering (RS) probe (Au-GIgG) for quantitation of trace immunoglobulin M (IgM). The Au-GIgG combined with IgM to form nanogold-labeled immunocomplex causes the RS intensity at 580 nm to be enhanced, in pH 4.49 KH2PO 4-Na2HPO4 buffer and in the presence of polyethylene glycol 6000. The enhanced RS intensity at 580 nm (ΔI580 nm) is proportional to the IgM concentration in the range of 1.5 to 2000 ng/mL, with a lower detection limit of 0.98 ng/mL. The immunonanogold RS assay was used to assay IgM in serum samples, with sensitivity, selectivity, and simplicity. ( Journal of Biomolecular Screening 2008:302-308)

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