scholarly journals A Multifunctional N-Doped Cu–MOFs (N–Cu–MOF) Nanomaterial-Driven Electrochemical Aptasensor for Sensitive Detection of Deoxynivalenol

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2243
Author(s):  
Xiaoyan Wen ◽  
Qingwen Huang ◽  
Dongxia Nie ◽  
Xiuying Zhao ◽  
Haojie Cao ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Food Samples ◽  
Electrical Signal ◽  
Hazardous Substances ◽  
Electrochemical Aptasensor ◽  
Signal Probe ◽  
Sensitive Determination ◽  
Linear Concentration Range ◽  
Linear Concentration

Deoxynivalenol (DON) is one of the most common mycotoxins in grains, causing gastrointestinal inflammation, neurotoxicity, hepatotoxicity and embryotoxicity, even at a low quantity. In this study, a facile electrochemical aptasensor was established for the rapid and sensitive determination of DON based on a multifunctional N-doped Cu-metallic organic framework (N–Cu–MOF) nanomaterial. The N–Cu–MOF, with a large specific surface area and good electrical conductivity, served not only as an optimal electrical signal probe but also as an effective supporting substrate for stabilizing aptamers through the interactions of amino (-NH2) and copper. Under the optimal conditions, the proposed sensor provided a wide linear concentration range of 0.02–20 ng mL−1 (R2 = 0.994), showing high sensitivity, with a lower detection limit of 0.008 ng mL−1, and good selectivity. The sensor’s effectiveness was also verified in real spiked wheat samples with satisfactory recoveries of 95.6–105.9%. The current work provides a flexible approach for the rapid and sensitive analysis of highly toxic DON in food samples and may also be easily extended to detect other hazardous substances with alternative target-recognition aptamers.

scholarly journals Quantitative Determination of Azithromycin in Human Plasma by Liquid Chromatography–Mass Spectrometry and its Application in Pharmackokinetic Study

2012 ◽  
Vol 11 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Maizbha Uddin Ahmed ◽  
Mohammad Safiqul Islam ◽  
Tasmin Ara Sultana ◽  
AGM Mostofa ◽  
Muhammad Shahdaat Bin Sayeed ◽  
...  
Keyword(s):  
Mobile Phase ◽  
Solid Phase ◽  
Internal Standard ◽  
Extraction Process ◽  
Serum Samples ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Linear Concentration Range ◽  
Linear Concentration

Azithromycin is an effective and well-known antimicrobial agent. In the present study, a simple, sensitive and specific LC/MS/MS method has been developed and validated for the quantification of Azithromycin in  human serum samples using Clarithromycin as internal standard. Azithromycin was extracted from biological matrix  by using solid phase extraction process. The chromatographic separation was performed on Luna C18 (3 ?, 2x150   mm) column with a mobile phase consisting of 35 mM ammonium acetate buffer (mobile phase-A) and acetonitrile  and methanol in ratio of 90:10 ( as mobile phase-B) at a flow rate of 0.25 mL/min. The method was validated over a  linear concentration range of 0.5?50.0 ng/mL and limit of quantification (LOQ) was 0.5 ng/mL with a coefficient of  correlation (r2) = 0.9998. The intra-day and inter-day precision expressed as relative standard deviation were 1.64% – 8.43% and 2.32% – 9.92%, respectively. The average recovery of azithromycin from serum was 98.11%. The method  was successfully applied to a pharmacokinetic study after oral administration of Azithromycin 200 mg/5 ml suspension in healthy Bangladeshi volunteers. DOI: http://dx.doi.org/10.3329/dujps.v11i1.12488 Dhaka Univ. J. Pharm. Sci. 11(1): 55-63, 2012 (June)

scholarly journals Fabrication of a Food Nano-Platform Sensor for Determination of Vanillin in Food Samples

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2817 ◽  
Author(s):  
Vinod Gupta ◽  
Hassan Karimi-Maleh ◽  
Shilpi Agarwal ◽  
Fatemeh Karimi ◽  
Majede Bijad ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Food Samples ◽  
Precipitation Method ◽  
Single Wall Carbon Nanotubes ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Paste Electrode

Herein, we describe the fabrication of NiO decorated single wall carbon nanotubes (NiO-SWCNTs) nanocomposites using the precipitation method. The synthesized NiO-SWCNTs nanocomposites were characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Remarkably, NiO-SWCNTs and 1-butylpyridinium hexafluorophosphate modified carbon paste electrode (CPE/NiO-SWCNTs/BPrPF6) were employed for the electrochemical detection of vanillin. The vanillin sensor showed an ultra-high sensitivity of 0.3594 μA/μM and a low detection limit of 0.007 μM. In the final step, the NiO-SWCNTs/BPrPF6 was used as the suitable tool for food analysis.

Simple and Cost Effective Polymer Modified Gold Nanoparticles Based on Colorimetric Determination of L-Cysteine in Food Samples

2021 ◽  
Vol 34 (1) ◽  
pp. 41-57
Author(s):  
Beeta Rani Khalkho ◽  
Anushree Saha ◽  
Bhuneshwari Sahu ◽  
Manas Kanti Deb
Keyword(s):  
Gold Nanoparticles ◽  
High Sensitivity ◽  
Cost Effective ◽  
Food Samples ◽  
Colorimetric Determination ◽  
Plasmon Resonance Band ◽  
Transmission Electron ◽  
Resonance Band ◽  
Absorbance Band

Abstract. The purpose of the present research was to design a method for the colorimetric determination of L-cysteine. We have employed PVA capped gold nanoparticles (GNPs) as a probe. The as-synthesized GNPs were further characterized by UV-vis absorption spectroscopy, transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and Zeta potential analyser. The results show that the presence of L-cysteine caused the quenching of the surface plasmon resonance band of the GNPs at 524 nm. It was accompanied by the appearance of a new absorbance of a new absorbance band at 670 nm. The color of the colloidal GNPs changed from wine red to blue. The change in color of the GNPs was due to their aggregation induced by the presence of L-cysteine. Based on these observations, the as-synthesized GNPs were utilized to develop a novel colorimetric sensor for L-cysteine detection in food samples. Significantly, other biomolecules such as alanine, proline, phenylalanine, tryptophane, valine, arginine, glutamic acid, lysine and histidine did not cause any change in the color of the GNPs solutions. This colorimetric probe showed excellent selectivity and high sensitivity for L-cysteine with a detection limit of 2.0 μg mL-1.

scholarly journals Use of a Ruthenium(III), Iron(II), and Nickel(II) Hexacyanometallate-Modified Graphite Electrode with Immobilized Oxalate Oxidase for the Determination of Urinary Oxalate

2001 ◽  
Vol 84 (6) ◽  
pp. 1927-1933 ◽  
Author(s):  
Stjepan Milardović ◽  
Zorana Grabarić ◽  
Vlatko Rumenjak ◽  
Nenad Blau ◽  
Dražen Milošević
Keyword(s):  
Ethylenediaminetetraacetic Acid ◽  
Graphite Electrode ◽  
Oxalate Oxidase ◽  
Urine Samples ◽  
Daily Routine ◽  
Urinary Oxalate ◽  
Catalyzed Oxidation ◽  
Linear Concentration Range ◽  
Linear Concentration

Abstract This paper describes the performance of a biosensor with an Ru(III), Ni(II), and Fe(II) hexacyanometallate-modified graphite electrode and immobilized oxalate oxidase for the determination of urinary oxalate. The addition of ruthenium enhances the electrochemical reversibility and chemical stability of the electrocrystallized layer and improves the sensitivity of the biosensor. Hydrogen peroxide, produced by the enzyme-catalyzed oxidation of oxalate, was measured at −50 mV vs an Hg|Hg2Cl2|3M KCl electrode in a solution of pH 3.6 succinic buffer, 0.1M KCl, and 5.4mM ethylenediaminetetraacetic acid. The linear concentration range for the determination of oxalate was 0.18–280 μM. The recoveries of added oxalate (10–35 μM) from aqueous solution ranged from 99.5 to 101.7%, whereas from urine samples without oxalate (or with a concentration of oxalate below the detection limit) the recoveries of added oxalate ranged from 91.4 to 106.6%. The oxalate in 24 h urine samples, taken during their daily routine from 35 infants and children, was measured and found to range from 0.6 to 121.7 mg/L. There were no interferences from uric acid, acetylsalicylic acid, and urea in the concentration range investigated, but paracetamol and ascorbic acid did interfere. A good correlation (R2 = 0.9242) was found between values obtained for oxalate in real urine samples by 2 laboratories, with the proposed biosensor and ion chromatography, respectively.

scholarly journals Technical advances in flow cytometry-based diagnosis and monitoring of paroxysmal nocturnal hemoglobinuria

2016 ◽  
Vol 14 (3) ◽  
pp. 366-373 ◽  
Author(s):  
Rodolfo Patussi Correia ◽  
Laiz Cameirão Bento ◽  
Ana Carolina Apelle Bortolucci ◽  
Anderson Marega Alexandre ◽  
Andressa da Costa Vaz ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Retrospective Study ◽  
Paroxysmal Nocturnal Hemoglobinuria ◽  
Laboratory Data ◽  
High Sensitivity ◽  
Laboratory Diagnosis ◽  
Clone Detection ◽  
Technical Advances ◽  
Sensitive Determination

ABSTRACT Objective: To discuss the implementation of technical advances in laboratory diagnosis and monitoring of paroxysmal nocturnal hemoglobinuria for validation of high-sensitivity flow cytometry protocols. Methods: A retrospective study based on analysis of laboratory data from 745 patient samples submitted to flow cytometry for diagnosis and/or monitoring of paroxysmal nocturnal hemoglobinuria. Results: Implementation of technical advances reduced test costs and improved flow cytometry resolution for paroxysmal nocturnal hemoglobinuria clone detection. Conclusion: High-sensitivity flow cytometry allowed more sensitive determination of paroxysmal nocturnal hemoglobinuria clone type and size, particularly in samples with small clones.

scholarly journals Label-Free and Sensitive Determination of Cadmium Ions Using a Ti-Modified Co3O4-Based Electrochemical Aptasensor

Biosensors ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 195
Author(s):  
Yang Liu ◽  
Dongwei Zhang ◽  
Jina Ding ◽  
Kashif Hayat ◽  
Xijia Yang ◽  
...  
Keyword(s):  
Environmental Protection Agency ◽  
Concentration Limit ◽  
Co3o4 Nanoparticles ◽  
Label Free ◽  
Current Signal ◽  
Electrochemical Aptasensor ◽  
Screen Printed Carbon Electrode ◽  
Sensitive Determination

The current work demonstrates an electrochemical aptasensor for sensitive determination of Cd2+ based on the Ti-modified Co3O4 nanoparticles. In this unlabeled system, Ti-modified Co3O4 nanoparticles act as current signal amplifiers modified on the screen-printed carbon electrode (SPCE) surface, while the derivative aptamer of Cd2+ works as a target recognizer. In addition, the sensing is based on the increase in electrochemical probe thionine current signal due to the binding of aptamer to Cd2+ via specific recognition. In the current study, key parameters, including aptamer concentration, pH, and incubation time were optimized, respectively, to ensure sensing performance. Cyclic voltammetry was used not only to characterize each preparation and optimization step, but also to profile the bindings of aptamer to Cd2+. Under optimal conditions, Cd2+ can be determined in a linear range of 0.20 to 15 ng/mL, with a detection limit of 0.49 ng/mL, significantly below the maximum concentration limit set by the U.S. Environmental Protection Agency. Based on comparative analysis and the results of recovery test with real samples, this simple, label-free but highly selective method has considerable potential and thus can be used as an in-situ environmental monitoring platform for Cd2+ testing.

Electrocatalysis and Sensitive Determination of Sudan I at Fe3O4/Graphene Modified Glassy Carbon Electrodes

2013 ◽  
Vol 401-403 ◽  
pp. 775-778
Author(s):  
Su Xing Luo ◽  
Yuan Hui Wu ◽  
Hua Gou
Keyword(s):  
Iron Oxide ◽  
Detection Limit ◽  
Electrochemical Method ◽  
Food Samples ◽  
Carbon Electrodes ◽  
Glassy Carbon Electrodes ◽  
Sudan I ◽  
Anodic Peak Current ◽  
Sensitive Determination

The iron oxide/graphene (Fe3O4/rGO) nanocomposite modified electrode and the electrochemical properties of Sudan I were investigated. It was found the anodic peak current of Sudan I was linear with the concentration of Sudan I from 0.008 μM to 6 μM with a detection limit of 0.0005 μM (S/N=3). The regression equation was: Ipa (μA)=-0.8151-0.9651c (μM), R=0.9934. It was convenient and excellent sensitive electrochemical method for Sudan I determination. This electrochemical method was successfully applied to determine Sudan I in food samples.

Highly Sensitive Determination of Dopamine Using Osmium/Nafion Modified Disposable Integrated Biosensor

2009 ◽  
Vol 60-61 ◽  
pp. 311-314 ◽  
Author(s):  
Chun Xiu Liu ◽  
Hong Min Liu ◽  
Qing De Yang ◽  
Nan Sen Lin ◽  
Yi Lin Song ◽  
...  
Keyword(s):  
Detection Limit ◽  
Correlation Coefficient ◽  
Gold Electrode ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Redox Polymer ◽  
Highly Sensitive ◽  
Sensitive Determination ◽  
Excellent Reproducibility

A biosensor based on gold electrode modified by Pt nanaoparticles/Osmium redox polymer/Nafion trilayer film was fabricated and used for selective and sensitive determination of dopamine. The biosensor is explored for DA sensing using the cyclic voltammetry (CV), amperometric and differential pulse voltammetric (DPV) methods. The CV anodic peak currents showed a linear range with a correlation coefficient of 0.996, localized in the concentration range 0~192 μM. The differential pulse voltammetric (DPV) peak currents were linear with DA concentration during 2~425 μM with correlation coefficient of 0.99. The biosensor showed high sensitivity of 0.5 nA /nM cm2 and excellent reproducibility with the detection limit of ~10 nM (S/N=3) for the determination of DA. The easy fabrication, low detection limit and high sensitivity of the integrated biosensor making it particularly suitable for the analytical purposes.

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