scholarly journals Fabrication of Nano/Micro-Structured Electrospun Detection Card for the Detection of Pesticide Residues

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 889
Author(s):  
Kun Feng ◽  
Meng-Yu Zhai ◽  
Yun-Shan Wei ◽  
Min-Hua Zong ◽  
Hong Wu ◽  
...  
Keyword(s):  
Absorption Efficiency ◽  
National Standard ◽  
Minimum Detectable Concentration ◽  
Pesticide Detection ◽  
Electrospinning Technique ◽  
Fiber Mats ◽  
Hydrophilic Modification ◽  
Food Detection ◽  
Fold Reduction ◽  
Detectable Concentration

A novel nano/micro-structured pesticide detection card was developed by combining electrospinning and hydrophilic modification, and its feasibility for detecting different pesticides was investigated. Here, the plain and hydrophilic-modified poly(ε-caprolactone) (PCL) fiber mats were used for the absorption of indolyl acetate and acetylcholinesterase (AChE), respectively. By pre-treating the fiber mat with ethanol, its surface wettability was improved, thus, promoting the hydrolysis of the PCL fiber mat. Furthermore, the absorption efficiency of AChE was improved by almost two times due to the increased hydrophilicity of the modified fiber mat. Noteworthily, this self-made detection card showed a 5-fold, 2-fold, and 1.5-fold reduction of the minimum detectable concentration for carbofuran, malathion, and trichlorfon, respectively, compared to the national standard values. Additionally, it also exhibited good stability when stored at 4 °C and room temperature. The food detection test showed that this nano/micro-based detection card had better detectability than the commercial detection card. Therefore, this study offers new insights into the design of pesticide detection cards, which also broadens the application of electrospinning technique.

scholarly journals CRISPR/Cas12a-Based Ultrasensitive and Rapid Detection of JAK2 V617F Somatic Mutation in Myeloproliferative Neoplasms

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 247
Author(s):  
Miaomiao Chen ◽  
Chunhua Zhang ◽  
Zhiqing Hu ◽  
Zhuo Li ◽  
Menglin Li ◽  
...  
Keyword(s):  
Detection System ◽  
Myeloproliferative Neoplasms ◽  
Cost Effective ◽  
Jak2 V617f ◽  
Jak2 V617f Mutation ◽  
Minimum Detectable Concentration ◽  
Lateral Flow Strip ◽  
Whole Process ◽  
Detectable Concentration ◽  
V617f Mutation

The JAK2 V617F mutation is a major diagnostic, therapeutic, and monitoring molecular target of Philadelphia-negative myeloproliferative neoplasms (MPNs). To date, numerous methods of detecting the JAK2 V617F mutation have been reported, but there is no gold-standard diagnostic method for clinical applications. Here, we developed and validated an efficient Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR associated protein 12a (Cas12a)-based assay to detect the JAK2 V617F mutation. Our results showed that the sensitivity of the JAK2 V617F/Cas12a fluorescence detection system was as high as 0.01%, and the JAK2 V617F/Cas12a lateral flow strip assay could unambiguously detect as low as 0.5% of the JAK2 V617F mutation, which was much higher than the sensitivity required for clinical application. The minimum detectable concentration of genomic DNA achieved was 0.01 ng/μL (~5 aM, ~3 copies/μL). In addition, the whole process only took about 1.5 h, and the cost of an individual test was much lower than that of the current assays. Thus, our methods can be applied to detect the JAK2 V617F mutation, and they are highly sensitive, rapid, cost-effective, and convenient.

Minimum Detectable Concentration as a Function of Gamma Walkover Survey Technique

2012 ◽  
Vol 102 (2) ◽  
pp. S22-S27
Author(s):  
David A. King ◽  
Nickolas Altic ◽  
Colt Greer
Keyword(s):  
Minimum Detectable Concentration ◽  
Survey Technique ◽  
Detectable Concentration

scholarly journals Isocratic High-Performance Liquid Chromatographic Method with Ultraviolet Detection for Simultaneous Determination of Levels of Voriconazole and Itraconazole and Its Hydroxy Metabolite in Human Serum

2005 ◽  
Vol 49 (8) ◽  
pp. 3569-3571 ◽  
Author(s):  
GholamAli Khoschsorur ◽  
Franz Fruehwirth ◽  
Sieglinde Zelzer
Keyword(s):  
Human Serum ◽  
Simultaneous Determination ◽  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Specific Method ◽  
Minimum Detectable Concentration ◽  
Detectable Concentration ◽  
One Step ◽  
Liquid Chromatographic

ABSTRACT A simple, specific method is presented for simultaneous determination of voriconazole and itraconazole and its metabolite, hydroxyitraconazole, in human serum using one-step liquid-liquid extraction and high-performance liquid chromatography. Linearity tests ranged from 0.1 to 8.0 μg/ml; the minimum detectable concentration was 0.03 μg/ml.

scholarly journals Core-Shell Nanofibers of Polyvinylidene Fluoride-based Nanocomposites as Piezoelectric Nanogenerators

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2344
Author(s):  
Deepalekshmi Ponnamma ◽  
Mariem Mohammed Chamakh ◽  
Abdulrhman Mohmmed Alahzm ◽  
Nisa Salim ◽  
Nishar Hameed ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Wearable Electronics ◽  
Hybrid Nanocomposite ◽  
Mechanical Vibrations ◽  
Electrospinning Technique ◽  
Fiber Mats ◽  
Semiconducting Metal Oxides ◽  
Soft Electronics ◽  
Human Motions ◽  
Piezoelectric Nanogenerators

Flexible piezoelectric nanogenerators (PENG) are widely applied to harvest sustainable energy from multiple energy sources. The rational and simple design of PENG have great potential in soft electronics. Here we design a highly flexible PENG using the polyvinylidene fluoride (PVDF) and its copolymer, polyvinylidene hexafluoropropylene (PVDF-HFP) with two nanoarchitectures of semiconducting metal oxides, TiO2 and ZnO. The nanotubes of TiO2 and nanoflowers of ZnO are embedded in these different polymeric media by solvent mixing, and new fiber mats are generated by coaxial electrospinning technique. This process aligns the dipoles of polymers and nanomaterials, which is normally a pre-requisite for higher piezo potential. With excellent mechanical strength and flexibility, the tailored lightweight fiber mats are capable of producing good output voltage (a maximum of 14 V) during different mechanical vibrations at various frequencies and in response to human motions. The hybrid nanocomposite PENG is durable and inexpensive and has possible applications in wearable electronics.

Noncompetitive enzyme-linked immunoassay for apolipoprotein B in serum.

1984 ◽  
Vol 30 (1) ◽  
pp. 98-100 ◽  
Author(s):  
C Fievet ◽  
M Koffigan ◽  
D Ouvry ◽  
S Marcovina ◽  
Y Moschetto ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Human Plasma ◽  
Apolipoprotein B ◽  
Solid Phase ◽  
Minimum Detectable Concentration ◽  
Low Density ◽  
Apo B ◽  
Detectable Concentration ◽  
Sensitivity Specificity ◽  
Assay Conditions

Abstract We used a noncompetitive enzyme-linked immunoassay to measure apolipoprotein B (apo-B) concentration in human plasma. Goat anti-lipoprotein B immunoglobulins were adsorbed to the surface of polystyrene balls. After washing, this solid-phase antibody was incubated with antigen (plasma from normal or hyperlipoproteinemic fasting subjects), washed, and then incubated with peroxidase-labeled goat anti-lipoprotein B IgG. After a last washing, we measured the bound label, which provided a direct measurement of the antigen. Under optimized assay conditions, the minimum detectable concentration was 50 ng per assay. The assay may be used to measure apo-B in different lipoprotein fractions (low- or very-low-density) and yields values that compared favorably with those obtained by electroimmunoassay (r = 0.86). The assay offers several advantages over existing techniques: sensitivity, specificity, simplicity, avoidance of radioisotopes, and potential for use with monoclonal antibodies.

Clinical and laboratory evaluation of a radioimmunoassay kit for measuring the mid-molecule fraction of parathyrin.

1986 ◽  
Vol 32 (11) ◽  
pp. 2056-2059 ◽  
Author(s):  
V M Haver ◽  
A D Rinker ◽  
B M Ko ◽  
N W Tietz
Keyword(s):  
Amino Acid ◽  
Clinical Evaluation ◽  
Turnaround Time ◽  
Medical Laboratory ◽  
Laboratory Evaluation ◽  
Minimum Detectable Concentration ◽  
Amino Acid Residues ◽  
Parathyroid Function ◽  
Detectable Concentration ◽  
Commercial Kit

Abstract We report the results of a laboratory and clinical evaluation of a commercial kit procedure (Immuno Nuclear Corp.) for measuring the mid-region of the parathyrin molecule. The estimated dose at 50% binding averaged 130 pmol/L, and the minimum detectable concentration was 14 pmol/L. The within-assay CV was less than or equal to 6.6%, the between-assay CV less than or equal to 12.5%. Relative analytical recoveries of various parathyrin fragments averaged 93% (intact, amino acid residues 1-84), 100% (midregion, 44-68), less than 0.01% (N-terminal, 1-34), and less than 0.01% (C-terminal, 69-84). Correlation of results obtained for 59 patients' samples with a radioimmunoassay for midregion/C-terminal parathyrin performed by the Mayo Medical Laboratory yielded the equation INC = 1.16 (Mayo)-1.94 pmol/L (r = 0.971). Clinical evaluation indicates that the INC results for parathyrin correlate with the diagnoses of patients at least as well as the results obtained with the Mayo assay; in some cases, the INC procedure better distinguishes hyperfunction from normal parathyroid function. The INC procedure can be easily performed in hospital laboratories, with a 4-h turnaround time for results.

scholarly journals Multicenter Clinical and Analytical Evaluation of the AxSYM Troponin-I Immunoassay to Assist in the Diagnosis of Myocardial Infarction

1999 ◽  
Vol 45 (2) ◽  
pp. 206-212 ◽  
Author(s):  
Fred S Apple ◽  
Andrew J Maturen ◽  
Richard E Mullins ◽  
Pennell C Painter ◽  
Melissa S Pessin-Minsley ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Muscle Injury ◽  
Troponin I ◽  
Dynamic Range ◽  
Chronic Renal Disease ◽  
Noncardiac Surgery ◽  
Minimum Detectable Concentration ◽  
Healthy Individuals ◽  
Detectable Concentration ◽  
Serial Samples

Abstract We evaluated the AxSYM troponin I (cTnI) immunoassay for assisting in the detection of acute myocardial infarction (AMI). At four sites, the total imprecision (CV) over 20 days was 6.3–10.2%. The minimum detectable concentration was 0.14 ± 0.05 μg/L. Comparison of cTnI measurements between the AxSYM and Stratus (n = 406) over the dynamic range of the AxSYM assay demonstrated good correlation, r = 0.881, with a proportional bias: AxSYM cTnI = 3.50(Stratus cTnI) − 1.10. The confidence intervals (95%) for the slope and intercept were 3.39–3.64 and −1.32 to −0.95, respectively. The expected cTnI concentration in healthy individuals was ≤0.5 μg/L, whereas the ROC curve-determined cutoff for AMI was 2.0 μg/L. This gave a diagnostic sensitivity of 91.8% and specificity of 92.4% when tested in serial samples collected within 24 h of admission in 633 patients presenting with chest pain, of which 122 had an AMI. The concordances of the AxSYM cTnI with the Stratus cTnI, OPUS cTnI, and Access cTnI were 95.3%, 95.1%, and 94.3%, respectively, from patients with suspected AMI. The AxSYM cTnI demonstrated excellent clinical specificity, ≥96%, in skeletal muscle injury, chronic renal disease, and same-day noncardiac surgery patients.

Determination of Citrinin in Corn and Barley on Thin Layer Chromatographic Plates Impregnated with Glycolic Acid

1984 ◽  
Vol 67 (1) ◽  
pp. 194-196
Author(s):  
Alberto Gimeno
Keyword(s):  
Thin Layer ◽  
Glycolic Acid ◽  
Detection Method ◽  
Minimum Detectable Concentration ◽  
Extraction Solvent ◽  
Detectable Concentration ◽  
Tlc Plates ◽  
Limit Detection ◽  
Layer Chromatography

Abstract A method is described for the determination of citrinin in corn and barley. The mycotoxin is extracted with a mixture of acetonitrile-10% glycolic acid in water, defatted with isooctane, and transferred to chloroform according to published methods. The mycotoxin is separated by thin layer chromatography (TLC) on plates previously impregnated with 10% glycolic acid solution in ethanol; identity is confirmed by chemical tests. Citrinin is then quantitated by the limit detection method. Recoveries of citrinin from corn and barley samples spiked at levels of 50, 80, 150, 300, 500, and 1000 μg/kg were in the range 91-98%. The minimum detectable concentration is 15-20 μg/ kg. Recoveries obtained with and without glycolic acid in the extraction solvent were compared. Sensitivities on TLC plates (limits of detection, μg/spot) impregnated with glycolic acid were compared with those on plates impregnated with oxalic acid.

Colorimetry of hemoglobin in plasma with 2,2'-azino-di(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS).

1984 ◽  
Vol 30 (3) ◽  
pp. 357-359 ◽  
Author(s):  
M Takayanagi ◽  
T Yashiro
Keyword(s):  
Hydrogen Peroxide ◽  
Calibration Curve ◽  
Plasma Proteins ◽  
Sulfonic Acid ◽  
Minimum Detectable Concentration ◽  
Colored Form ◽  
Analytical Recovery ◽  
Detectable Concentration ◽  
Precision And Accuracy

Abstract Hemoglobin in plasma can be determined by the color-developing action of 2,2'-azino-di(3-ethylbenzthiazoline-6-sulfonic acid), which is oxidized to a colored form by a peroxidase-like effect of hemoglobin in the presence of hydrogen peroxide. Sensitivity, precision, and accuracy are discussed. The calibration curve is linear for hemoglobin concentrations up to 1 g/L; the minimum detectable concentration is 20 mg/L. The within-run precision (CV) was 2.39%, analytical recovery 101.8%. Interference from plasma proteins and lipids was eliminated by centrifuging the reaction mixture before measuring its absorbance at 410 nm.

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