scholarly journals An Origami Paper-Based Analytical Device for Rapid and Sensitive Analysis of Acrylamide in Foods

Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 13
Author(s):  
Yu Yan ◽  
Dan Zhao ◽  
Weiming Li ◽  
Xiaoqian Li ◽  
Yangyang Chang ◽  
...  
Keyword(s):  
Food Safety ◽  
Limit Of Detection ◽  
Colorimetric Detection ◽  
Food Samples ◽  
Sensitive Detection ◽  
Optimal Conditions ◽  
Folding Paper ◽  
Assay Time ◽  
Analytical Device ◽  
Signal Readout

Rapid and sensitive detection of acrylamide in food samples is important for food safety and public health. Here, we describe a disposable origami paper-based analytical device (denoted doPAD) for colorimetric detection of acrylamide. This device uniquely exploits 3D origami folding paper for spatial control of the target recognition and signal readout, thus resulting in a positive correlation between the signals and the analytes. Under optimal conditions, the device achieved the quantitative analysis of acrylamide with a limit of detection of 1.13 μg/L within 120 min (including a derivatization time of 90 min and an assay time of 21 min). Furthermore, our method allowed the rapid and sensitive detection of acrylamide in complex food matrices. We envision that the platform described will find useful applications in the fields of food safety and environmental health.

scholarly journals Molecular Diagnostic of Ochratoxin A with Specific Aptamers in Corn and Groundnut via Fabrication of A Microfluidic Device

2021 ◽  
Author(s):  
Deepshikha Shahdeo ◽  
Azmat Ali Khan ◽  
Amer M Alanazi ◽  
Yun Suk Huh ◽  
Shruti Shukla ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Limit Of Detection ◽  
Colorimetric Assay ◽  
Animal Health ◽  
Colorimetric Detection ◽  
Molecular Diagnostic ◽  
Detection Range ◽  
Vis Spectroscopy ◽  
Wide Range ◽  
Analytical Device

Abstract Ochratoxin A (OTA) is one of the predominant mycotoxins that contaminate a wide range of food commodities. In the present study, a 36-mer aptamer was used as a molecular recognition element coupled with gold nanoparticles (AuNPs) for colorimetric detection of OTA in a microfluidic paper-based analytical device (µPADs). The µPADs consisted of three zones: control, detection, and sample, interconnected by channels. The biophysical characterizations of aptamer conjugated AuNPs were done by UV-vis spectroscopy (UV-vis), dynamic Light Scattering (DLS), and transmission electron microscopy (TEM). The developed colorimetric assay for OTA showed a limit of detection of 242, 545, and 95.69 ng/mL in water, corn, and groundnut, respectively. The HPLC detection method achieved acceptable coefficient in standard curves (r2 = 0.9995), better detection range, and recovery rates in spiked corn and groundnut samples as 43.61 ± 2.18% to 87.10 ± 1.82% and 42.01 ± 1.31% to 86.03 ± 2.64% after multiple sample extractions and cleanup steps. However, the developed µPADs analytical device had the potent ability to rapidly detect OTA without any extraction pre-requirement, derivatization, and cleanup steps, thus illustrating its feasibility in the animal health sector, agricultural, and food industries.

scholarly journals Highly Sensitive and Selective Colorimetric Detection of Methylmercury Based on DNA Functionalized Gold Nanoparticles

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2679 ◽  
Author(s):  
Zheng-Jun Xie ◽  
Xian-Yu Bao ◽  
Chi-Fang Peng
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Limit Of Detection ◽  
Low Cost ◽  
Colorimetric Detection ◽  
Colorimetric Method ◽  
Optimal Conditions ◽  
Surface Deposition ◽  
Highly Sensitive ◽  
Dna Strand

A new colorimetric detection of methylmercury (CH3Hg+) was developed, which was based on the surface deposition of Hg enhancing the catalytic activity of gold nanoparticles (AuNPs). The AuNPs were functionalized with a specific DNA strand (HT7) recognizing CH3Hg+, which was used to capture and separate CH3Hg+ by centrifugation. It was found that the CH3Hg+ reduction resulted in the deposition of Hg onto the surface of AuNPs. As a result, the catalytic activity of the AuNPs toward the chromogenic reaction of 3,3,5,5-tetramethylbenzidine (TMB)-H2O2 was remarkably enhanced. Under optimal conditions, a limit of detection of 5.0 nM was obtained for CH3Hg+ with a linear range of 10–200 nM. We demonstrated that the colorimetric method was fairly simple with a low cost and can be conveniently applied to CH3Hg+ detection in environmental samples.

Tropomyosin Analysis in Foods Using an Electrochemical Immunosensing Approach

2021 ◽  
Vol 5 (1) ◽  
pp. 62
Author(s):  
Ricarda Torre ◽  
Maria Freitas ◽  
Estefanía Costa-Rama ◽  
Henri P. A. Nouws ◽  
Cristina Delerue-Matos
Keyword(s):  
Limit Of Detection ◽  
Polyclonal Antibodies ◽  
Analytical Signal ◽  
Food Samples ◽  
Electrochemical Immunosensor ◽  
Screen Printed Carbon Electrode ◽  
Sandwich Type ◽  
Assay Time ◽  
Electrochemical Immunosensing

A screen-printed carbon electrode was used as the transducer for the development of an electrochemical immunosensor for the determination of tropomyosin (a major shrimp allergen) in food samples. Monoclonal and polyclonal antibodies were used in a sandwich-type immunoassay. The analytical signal was electrochemically obtained using an alkaline phosphatase-labelled secondary antibody and a 3-indoxyl phosphate/silver nitrate substrate. The total assay time was 2 h 50 min and allowed the quantification of tropomyosin between 2.5 and 20 ng mL−1, with a limit of detection of 1.7 ng mL−1 The immunosensor was successfully applied to the analysis of commercial food products.

scholarly journals Colorimetric detection of organophosphates with cysteamine capped gold nanoparticle sensors

2020 ◽  
Author(s):  
Muhammad Musaddiq Shah ◽  
Wen Ren ◽  
Bashir Ahmad ◽  
Joseph Irudayaraj
Keyword(s):  
Gold Nanoparticle ◽  
Limit Of Detection ◽  
Colorimetric Detection ◽  
High Sensitivity ◽  
Food Samples ◽  
Quantitative Detection ◽  
Enzyme Mimics ◽  
Nanoparticle Probes ◽  
Site Monitoring ◽  
20 Nm

Nanozyme biosensors have the potential to provide high sensitivity, multiple functionality, and tunable activity. A facile colorimetric biosensor for the detection of organophosphates (OPs) using cysteamine capped gold nanoparticle probes (C-AuNPs) as enzyme mimics is proposed. Parathion ethyl (PE) a class of OPs is a potent insecticide that functions by inhibiting the acetylcholinesterase (AChE) in the nervous system of insects. The inhibition kinetics of AChE using PE enables the development of a PE sensor. C-AuNPs possess the ability to catalyze the oxidization of 3, 3’, 5, 5’-tetramethylbenzidine (TMB) to a blue-colored product without peroxidase. The detection of PE was monitored by the inability of AChE to generate choline. Choline causes the aggregation of C-AuNPs and the aggregated C-AuNPs has decreased ability to catalyze the oxidization of TMB. A calibration was developed in the 40-320 nM range for the quantitative detection of PE. The limit of detection observed was 20 nM and the method had excellent specificity. The proposed sensor provides an excellent platform for on-site monitoring of PE in environmental and food samples with high sensitivity and greater selectivity.

scholarly journals Black phosphorus-Au nanocomposite-based fluorescence immunochromatographic sensor for high-sensitive detection of zearalenone in cereals

Nanophotonics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 2397-2406
Author(s):  
Shijie Li ◽  
Fuyuan Zhang ◽  
Junping Wang ◽  
Wenjun Wen ◽  
Shuo Wang
Keyword(s):  
Quantum Dots ◽  
Food Safety ◽  
Fluorescence Quenching ◽  
Density Functional ◽  
Limit Of Detection ◽  
Black Phosphorus ◽  
Sensitive Detection ◽  
The Density Functional Theory ◽  
Quenching Efficiency ◽  
Novel Method

AbstractRapid and high-sensitive detection of mycotoxins is believed to be of vital importance in assuring food safety. In this study, we developed a novel fluorescence immunochromatographic sensor (ICS) for the mycotoxin of zearalenone (ZEN) in cereals. This was done by using a black phosphorus-Au nanocomposite (BP-Au) as the 2D quenching platform. Herein, gold nanoparticles (AuNPs) were directly reduced on the surface of BP nanosheets (BPNSs) to form BP-Au nanocomposites, showing higher fluorescence (quantum dots, λEm = 525 nm) quenching efficiency compared to the BPNSs and AuNPs. The fluorescence quenching efficiency of the prepared BP-Au nanocomposite reached 73.8%, which was 1.73-fold and 1.44-fold higher than AuNPs and BPNSs, respectively. The density functional theory was also successfully used to explore the formation mechanism of the BP-Au nanocomposite. By introducing the quantum dots/BP-Au signal/quencher pair, a high-sensitive fluorescence quenching ICS (B-FICS) was developed for the detection and discrimination of ZEN with the limit of detection of 0.1 μg/l in pure working buffer. This was 2.5-fold more sensitive than AuNPs-based FICS (A-FICS). The B-FICS was successfully applied in real cereals detection with the sample limit of detection of 2 μg/kg. The successful construction of B-FICS offers a novel method for a rapid and high-sensitive detection of ZEN in cereals. It also provides a new practical application of 2D BPNSs in food safety sensing.

scholarly journals Fe3O4Nanoparticles Loaded on Lignin Nanoparticles Applied as a Peroxidase Mimic for the Sensitively Colorimetric Detection of H2O2

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 210 ◽  
Author(s):  
Qingtong Zhang ◽  
Mingfu Li ◽  
Chenyan Guo ◽  
Zhuan Jia ◽  
Guangcong Wan ◽  
...  
Keyword(s):  
Self Assembly ◽  
Limit Of Detection ◽  
Paper Industry ◽  
Colorimetric Detection ◽  
Renewable Resource ◽  
High Catalytic Activity ◽  
Blue Color ◽  
Optimal Conditions ◽  
Peroxidase Mimic ◽  
Assembly Method

Lignin is the second largest naturally renewable resource and is primarily a by-product of the pulp and paper industry; however, its inefficient use presents a challenge. In this work, Fe3O4 nanoparticles loaded on lignin nanoparticles (Fe3O4@LNPs) were prepared by the self-assembly method and it possessed an enhanced peroxidase-like activity. Fe3O4@LNPs catalyzed the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2 to generate a blue color, was observable by the naked eye. Under the optimal conditions, Fe3O4@LNPs showed the ability of sensitive colorimetric detection of H2O2within a range of 5–100 μM and the limit of detection was 2 μM. The high catalytic activity of Fe3O4@LNPs allows its prospective use in a wide variety of applications, including clinical diagnosis, food safety, and environmental monitoring.

A Point of Care Lateral Flow Assay for Rapid and Colorimetric Detection of Interleukin 6 and Perspectives in Bedside Diagnostics

2020 ◽  
Author(s):  
Carla Eiras
Keyword(s):  
Interleukin 6 ◽  
Limit Of Detection ◽  
Inflammatory Diseases ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Aggregation Assay ◽  
Before And After ◽  
Bedside Diagnosis

Interleukin-6 (IL-6) is a multifunctional cytokine and high bloodstream levels of which have been associated with severe inflammatory diseases, such as dengue fever, sepsis, various cancers, and visceral leishmaniasis (VL). Rapid tests for the quantification of IL-6 would be of great assistance for the bedside diagnosis and treatment of diseases such as VL. We have developed a lateral flow assay (LFA) for rapid and colorimetric IL-6 detection, consisting of anti-IL-6 antibodies conjugated to gold nanoparticles (AuNPs). The optimal concentration of anti-IL-6 used in the conjugate was determined to be 800.0 μg/mL, based on an aggregation assay using LFA. A linear relationship between IL-6 standard concentration and color intensity was observed after 20 min, with a linear range between 1.25 ng/mL and 9,000 ng/mL. The limit of detection for this method was estimated a t0.38 ng/mL. The concentration of IL-6 in five patients with severe VL was measured using LFA, and the results were consistent with those obtained using the cytometric bead array (CBA) method. A thorough analysis of the LFA membranes’ surface morphology, before and after sample contact, was performed using atomic force microscopy (AFM).The prototype described here is still being tested and improved, but this LFA will undoubtedly be of great help in the clinical quantification of IL-6.

A Point of Care Lateral Flow Assay for Rapid and Colorimetric Detection of Interleukin 6 and Perspectives in Bedside Diagnostics

2020 ◽  
Author(s):  
Carla Eiras
Keyword(s):  
Interleukin 6 ◽  
Limit Of Detection ◽  
Inflammatory Diseases ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Aggregation Assay ◽  
Before And After ◽  
Bedside Diagnosis

Interleukin-6 (IL-6) is a multifunctional cytokine and high bloodstream levels of which have been associated with severe inflammatory diseases, such as dengue fever, sepsis, various cancers, and visceral leishmaniasis (VL). Rapid tests for the quantification of IL-6 would be of great assistance for the bedside diagnosis and treatment of diseases such as VL. We have developed a lateral flow assay (LFA) for rapid and colorimetric IL-6 detection, consisting of anti-IL-6 antibodies conjugated to gold nanoparticles (AuNPs). The optimal concentration of anti-IL-6 used in the conjugate was determined to be 800.0 μg/mL, based on an aggregation assay using LFA. A linear relationship between IL-6 standard concentration and color intensity was observed after 20 min, with a linear range between 1.25 ng/mL and 9,000 ng/mL. The limit of detection for this method was estimated at a t0.38 ng/mL. The concentration of IL-6 in five patients with severe VL was measured using LFA, and the results were consistent with those obtained using the cytometric bead array (CBA) method. A thorough analysis of the LFA membranes’ surface morphology, before and after sample contact, was performed using atomic force microscopy (AFM). The prototype described here is still being tested and improved, but this LFA will undoubtedly be of great help in the clinical quantification of IL-6.

Naked-eye colorimetric detection of HCV RNA mediated by a 5′ UTR-targeted antisense oligonucleotide and plasmonic gold nanoparticles

The Analyst ◽  
2021 ◽  
Author(s):  
Almas Shamaila Mohammed ◽  
Aniket Balapure ◽  
Mahammad Nanne Khaja ◽  
Ramakrishnan Ganesan ◽  
Jayati Ray Dutta
Keyword(s):  
Gold Nanoparticles ◽  
Antisense Oligonucleotide ◽  
Early Stage ◽  
Colorimetric Detection ◽  
Sensitive Detection ◽  
Clinical Samples ◽  
Hcv Rna ◽  
Naked Eye

An Au NP based facile strategy for the rapid, early-stage, and sensitive detection of HCV RNA in clinical samples which avoids thiol tagging to the antisense oligonucleotide and expensive infrastructure is presented.

scholarly journals Highly sensitive and selective colorimetric detection of dual metal ions (Hg2+ and Sn2+) in water: an eco-friendly approach

RSC Advances ◽  
2021 ◽  
Vol 11 (24) ◽  
pp. 14700-14709
Author(s):  
Rintumoni Paw ◽  
Moushumi Hazarika ◽  
Purna K. Boruah ◽  
Amlan Jyoti Kalita ◽  
Ankur K. Guha ◽  
...  
Keyword(s):  
Metal Ions ◽  
Ag Nanoparticles ◽  
Limit Of Detection ◽  
Colorimetric Detection ◽  
Garlic Extract ◽  
Selective Detection ◽  
Highly Sensitive ◽  
Dual Metal

Synthesis of Ag nanoparticles using Allin based garlic extract for highly sensitive and selective detection of metal ions Hg2+ and Sn2+ in water. The limit of detection (LoD) for Hg2+ and Sn2+ ions were found as 15.7 nM and 11.25 nM respectively.

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