scholarly journals Gold Nanoparticle Sensor for the Visual Detection of Pork Adulteration in Meatball Formulation

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
M. E. Ali ◽  
U. Hashim ◽  
S. Mustafa ◽  
Y. B. Che Man ◽  
Kh. N. Islam
Keyword(s):  
Annealing Temperature ◽  
Visual Detection ◽  
Low Cost ◽  
Absorption Peak ◽  
Label Free ◽  
Food Standards ◽  
Kosher Food ◽  
20 Nm ◽  
Induced Aggregation ◽  
Critical Annealing

We visually identify pork adulteration in beef and chicken meatball preparations using 20 nm gold nanoparticles (GNPs) as colorimetric sensors. Meatball is a popular food in certain Asian and European countries. Verification of pork adulteration in meatball is necessary to meet the Halal and Kosher food standards. Twenty nm GNPs change color from pinkish-red to gray-purple, and their absorption peak at 525 nm is red-shifted by 30–50 nm in 3 mM phosphate buffer saline (PBS). Adsorption of single-stranded DNA protects the particles against salt-induced aggregation. Mixing and annealing of a 25-nucleotide (nt) single-stranded (ss) DNA probe with denatured DNA of different meatballs differentiated well between perfectly matched and mismatch hybridization at a critical annealing temperature. The probes become available in nonpork DNA containing vials due to mismatches and interact with GNPs to protect them from salt-induced aggregation. Whereas, all the pork containing vials, either in pure and mixed forms, consumed the probes totally by perfect hybridization and turned into grey, indicating aggregation. This is clearly reflected by a well-defined red-shift of the absorption peak and significantly increased absorbance in 550–800 nm regimes. This label-free low-cost assay should find applications in food analysis, genetic screening, and homology studies.

scholarly journals Demonstration of a Label-Free and Low-Cost Optical Cavity-Based Biosensor Using Streptavidin and C-Reactive Protein

Biosensors ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 4
Author(s):  
Donggee Rho ◽  
Seunghyun Kim
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Optical Cavity ◽  
Sample Volume ◽  
Small Sample ◽  
Label Free ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Cavity Structure

An optical cavity-based biosensor (OCB) has been developed for point-of-care (POC) applications. This label-free biosensor employs low-cost components and simple fabrication processes to lower the overall cost while achieving high sensitivity using a differential detection method. To experimentally demonstrate its limit of detection (LOD), we conducted biosensing experiments with streptavidin and C-reactive protein (CRP). The optical cavity structure was optimized further for better sensitivity and easier fluid control. We utilized the polymer swelling property to fine-tune the optical cavity width, which significantly improved the success rate to produce measurable samples. Four different concentrations of streptavidin were tested in triplicate, and the LOD of the OCB was determined to be 1.35 nM. The OCB also successfully detected three different concentrations of human CRP using biotinylated CRP antibody. The LOD for CRP detection was 377 pM. All measurements were done using a small sample volume of 15 µL within 30 min. By reducing the sensing area, improving the functionalization and passivation processes, and increasing the sample volume, the LOD of the OCB are estimated to be reduced further to the femto-molar range. Overall, the demonstrated capability of the OCB in the present work shows great potential to be used as a promising POC biosensor.

scholarly journals Integrating high-performing electrochemical transducers in lateral flow assay

2021 ◽  
Author(s):  
Antonia Perju ◽  
Nongnoot Wongkaew
Keyword(s):  
High Performance ◽  
Point Of Care ◽  
Low Cost ◽  
High Sensitivity ◽  
Lateral Flow ◽  
Analytical Performance ◽  
Label Free ◽  
High Performing ◽  
Lateral Flow Assays ◽  
Electrochemical Transducers

AbstractLateral flow assays (LFAs) are the best-performing and best-known point-of-care tests worldwide. Over the last decade, they have experienced an increasing interest by researchers towards improving their analytical performance while maintaining their robust assay platform. Commercially, visual and optical detection strategies dominate, but it is especially the research on integrating electrochemical (EC) approaches that may have a chance to significantly improve an LFA’s performance that is needed in order to detect analytes reliably at lower concentrations than currently possible. In fact, EC-LFAs offer advantages in terms of quantitative determination, low-cost, high sensitivity, and even simple, label-free strategies. Here, the various configurations of EC-LFAs published are summarized and critically evaluated. In short, most of them rely on applying conventional transducers, e.g., screen-printed electrode, to ensure reliability of the assay, and additional advances are afforded by the beneficial features of nanomaterials. It is predicted that these will be further implemented in EC-LFAs as high-performance transducers. Considering the low cost of point-of-care devices, it becomes even more important to also identify strategies that efficiently integrate nanomaterials into EC-LFAs in a high-throughput manner while maintaining their favorable analytical performance.

Low-cost flexible plasmonic nanobump metasurfaces for label-free sensing of serum tumor marker

2020 ◽  
Vol 150 ◽  
pp. 111905 ◽  
Author(s):  
Jinfeng Zhu ◽  
Zhengying Wang ◽  
Shaowei Lin ◽  
Shan Jiang ◽  
Xueying Liu ◽  
...  
Keyword(s):  
Tumor Marker ◽  
Low Cost ◽  
Label Free ◽  
Serum Tumor Marker

Development of Bioimpedance Sensors and Measurement System for Biomedical In-Vitro Applications

2021 ◽  
Vol 7 (2) ◽  
pp. 496-499
Author(s):  
Stadler B. Eng. Sebastian ◽  
Herbert Plischke ◽  
Christian Hanshans
Keyword(s):  
Measurement System ◽  
Low Cost ◽  
Measurement Data ◽  
Impedance Measurement ◽  
Microtiter Plate ◽  
Label Free ◽  
Single Chip ◽  
Do It Yourself ◽  
Store And Forward

Abstract Bioimpedance analysis is a label-free and easy approach to obtain information on cellular barrier integrity and cell viability more broadly. In this work, we introduce a small, low-cost, portable in vitro impedance measurement system for studies where a shadow-free exposure of the cells is a requirement. It can be controlled by a user-friendly web interface and can perform measurements automated and autonomously at short intervals. The system can be integrated into an existing IoT network for remote monitoring and indepth analyses. A single-board computer (SBC) serves as the central unit, to control, analyze, store and forward the measurement data from the single-chip impedance analyzer. Various materials and manufacturing methods were used to produce a purpose-built lid on top of a modified 24-well microtiter plate in a “do it yourself” fashion. Furthermore, three different sensor designs were developed utilizing anodic aluminum oxide (AAO) membranes and gold-plated electrodes. Preliminary tests with potassium chloride (KCl) showed first promising results.

Selection of an aptamer against Muscovy duck parvovirus for highly sensitive rapid visual detection by label-free aptasensor

Talanta ◽  
2018 ◽  
Vol 176 ◽  
pp. 214-220 ◽  
Author(s):  
Taofeng Lu ◽  
Qin Ma ◽  
Wenzhuo Yan ◽  
Yuanzhi Wang ◽  
Yuanyuan Zhang ◽  
...  
Keyword(s):  
Visual Detection ◽  
Muscovy Duck ◽  
Label Free ◽  
Highly Sensitive ◽  
Muscovy Duck Parvovirus ◽  
Selection Of

scholarly journals Catalytic Hydrogenation, Hydrodeoxygenation, and Hydrocracking Processes of a Lignin Monomer Model Compound Eugenol over Magnetic Ru/C–Fe2O3 and Mechanistic Reaction Microkinetics

Catalysts ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 425 ◽  
Author(s):  
Ana Bjelić ◽  
Miha Grilc ◽  
Sašo Gyergyek ◽  
Andraž Kocjan ◽  
Darko Makovec ◽  
...  
Keyword(s):  
Model Compound ◽  
Annealing Temperature ◽  
Low Cost ◽  
Value Added ◽  
Product Distribution ◽  
Surface Chemical ◽  
Annealing Temperatures ◽  
Microkinetic Model ◽  
Highly Active ◽  
Commercial Carbon

Conversion of waste lignocellulosic (LC) biomass, a widely-available low-cost feedstock, into value-added biobased chemicals (and biofuels) has been gaining much attention recently. Therefore, the present lignin valorisation study was aimed at developing magnetically-separable highly-active catalysts for hydrodeoxygenation (HDO), also proposing surface chemical kinetics. Five carbonaceous substrate-deposited Ru were synthesised and tested for the HDO of monomer moiety eugenol. Their annealing temperatures differed, specifically between 300 and 750 °C, while one was not subjected to calcination. Experiments revealed the substantial influence of annealing temperature on the product distribution. Namely, fresh nonannealed nanocomposites were not active for hydrogenolysis. By further pretreatment increase, hydrogenation and, exclusively, the deoxygenation of saturated cyclic species, were enhanced, these being more promoted considering rates and yields than commercial carbon-supported ruthenium. Over 80 mol% of 4-propyl-cylohexanol and propyl-cyclohexane could be formed over the samples, treated at 500 and 600 °C, for 100 and 125 min, respectively, under 275 °C and 5 MPa of reactor hydrogen pressure. Interestingly, a notable 4-propyl-phenol amount was produced upon 750 °C pretreating. The intrinsic microkinetic model, developed previously, was applied to determine relevant turnover parameters. Calculated modelling results indicated a 47- and 10-fold greater demethoxylation and dehydroxylation mechanism ability upon the reheatingpreheating at 600 °C in comparison to industrial (heterogeneous) Ru/C.

Selection of a DNA Aptamer against Zearalenone and Docking Analysis for Highly Sensitive Rapid Visual Detection with Label-Free Aptasensor

2018 ◽  
Vol 66 (45) ◽  
pp. 12102-12110 ◽  
Author(s):  
Yuanyuan Zhang ◽  
Taofeng Lu ◽  
Yue Wang ◽  
Chenxi Diao ◽  
Yan Zhou ◽  
...  
Keyword(s):  
Visual Detection ◽  
Dna Aptamer ◽  
Label Free ◽  
Docking Analysis ◽  
Highly Sensitive ◽  
Selection Of

scholarly journals Rapid Antibody Selection Using Surface Plasmon Resonance for High-Speed and Sensitive Hazelnut Lateral Flow Prototypes

Biosensors ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 130 ◽  
Author(s):  
Georgina Ross ◽  
Maria Bremer ◽  
Jan Wichers ◽  
Aart van Amerongen ◽  
Michel Nielen
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
High Speed ◽  
Selection Process ◽  
Low Cost ◽  
Real Life ◽  
Cross Reactivity ◽  
Lateral Flow ◽  
Label Free

Lateral Flow Immunoassays (LFIAs) allow for rapid, low-cost, screening of many biomolecules such as food allergens. Despite being classified as rapid tests, many LFIAs take 10–20 min to complete. For a really high-speed LFIA, it is necessary to assess antibody association kinetics. By using a label-free optical technique such as Surface Plasmon Resonance (SPR), it is possible to screen crude monoclonal antibody (mAb) preparations for their association rates against a target. Herein, we describe an SPR-based method for screening and selecting crude anti-hazelnut antibodies based on their relative association rates, cross reactivity and sandwich pairing capabilities, for subsequent application in a rapid ligand binding assay. Thanks to the SPR selection process, only the fast mAb (F-50-6B12) and the slow (S-50-5H9) mAb needed purification for labelling with carbon nanoparticles to exploit high-speed LFIA prototypes. The kinetics observed in SPR were reflected in LFIA, with the test line appearing within 30 s, almost two times faster when F-50-6B12 was used, compared with S-50-5H9. Additionally, the LFIAs have demonstrated their future applicability to real life samples by detecting hazelnut in the sub-ppm range in a cookie matrix. Finally, these LFIAs not only provide a qualitative result when read visually, but also generate semi-quantitative data when exploiting freely downloadable smartphone apps.

scholarly journals Synchronous fluorescence as a green and selective tool for simultaneous determination of bambuterol and its main degradation product, terbutaline

2018 ◽  
Vol 5 (10) ◽  
pp. 181359 ◽  
Author(s):  
Samah Abo El Abass ◽  
Heba Elmansi
Keyword(s):  
Degradation Product ◽  
Low Cost ◽  
Reference Method ◽  
Cost Effective ◽  
Zero Crossing ◽  
Cost Effective Method ◽  
Validation Parameters ◽  
Main Degradation Product ◽  
20 Nm

A green, sensitive and cost-effective method is introduced in this research for the determination of bambuterol and its main degradation product, terbutaline, simultaneously, relying on the synchronous spectrofluorimetric technique. First derivative synchronous spectrofluorimetric amplitude is measured at Δ λ = 20 nm, so bambuterol can be quantitated at 260 nm, and terbutaline can be measured at 290 nm, each at the zero crossing point of the other. The amplitude–concentration plots were linear over the concentration ranges of 0.2–6.0 µg ml −1 and 0.2–4.0 µg ml −1 for both bambuterol and terbutaline, respectively. Official guidelines were followed to calculate the validation parameters of the proposed method. The low values of limits of detection of 0.023, 0.056 µg ml −1 and limits of quantitation of 0.071, 0.169 µg ml −1 for bambuterol and terbutaline, respectively, point to the sensitivity of the method. Bambuterol is a prodrug for terbutaline, and the latter is considered its degradation product so the established method could be regarded as a stability-indicating one. Moreover, the proposed method was used for the analysis of bambuterol and terbutaline in their single ingredient preparations and the results revealed statistical agreement with the reference method. The suggested method, being a simple and low-cost procedure, is superior to the previously published methods which need more sophisticated techniques, longer analysis time and highly toxic solvents and reagents. It could be considered as an eco-friendly analytical procedure.

Sign in / Sign up

Export Citation Format

Share Document