scholarly journals Development of a Lateral Flow Immunoassay (LFIA) to Screen for the Release of the Endocrine Disruptor Bisphenol A from Polymer Materials and Products

Biosensors ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 231
Author(s):  
Anna Raysyan ◽  
Rudolf J. Schneider
Keyword(s):  
Bisphenol A ◽  
Limit Of Detection ◽  
Lateral Flow ◽  
Polymer Materials ◽  
Contact Printing ◽  
Open Questions ◽  
Thermal Paper ◽  
Rapid Tests ◽  
Cost Efficient ◽  
Set Up

One of the most important chemicals used in the production of polymer plastics and coatings is bisphenol A. However, despite the large number of studies on the toxicity and hormonal activity of BPA, there are still open questions and thus considerable media attention regarding BPA toxicity. Hence, it is necessary to develop a sensitive, simple, cost-efficient, specific, portable, and rapid method for monitoring bisphenol A and for high sample throughput and on-site screening analysis. Lateral flow immunoassays have potential as rapid tests for on-site screening. To meet sensitivity criteria, they must be carefully optimized. A latex microparticle-based LFIA for detection of BPA was developed. The sensitivity of the assay was improved by non-contact printing of spot grids as the control and test lines with careful parameter optimization. Results of the test could be visually evaluated within 10 min with a visual cut-off of 10 µg/L (vLOD). Alternatively, photographs were taken, and image analysis performed to set up a calibration, which allowed for a calculated limit of detection (cLOD) of 0.14 µg/L. The method was validated for thermal paper samples against ELISA and LC–MS/MS as reference methods, showing good agreement with both methods.

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.

scholarly journals Multi-Quantum Dots-Embedded Silica-Encapsulated Nanoparticle-Based Lateral Flow Assay for Highly Sensitive Exosome Detection

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 768
Author(s):  
Hyung-Mo Kim ◽  
Chiwoo Oh ◽  
Jaehyun An ◽  
Seungki Baek ◽  
Sungje Bock ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Limit Of Detection ◽  
Specific Binding ◽  
Calf Serum ◽  
Lateral Flow ◽  
Lateral Flow Immunoassay ◽  
Uniform Size ◽  
Highly Sensitive ◽  
Wide Range ◽  
New Biomarkers

Exosomes are attracting attention as new biomarkers for monitoring the diagnosis and prognosis of certain diseases. Colorimetric-based lateral-flow assays have been previously used to detect exosomes, but these have the disadvantage of a high limit of detection. Here, we introduce a new technique to improve exosome detection. In our approach, highly bright multi-quantum dots embedded in silica-encapsulated nanoparticles (M–QD–SNs), which have uniform size and are brighter than single quantum dots, were applied to the lateral flow immunoassay method to sensitively detect exosomes. Anti-CD63 antibodies were introduced on the surface of the M–QD–SNs, and a lateral flow immunoassay with the M–QD–SNs was conducted to detect human foreskin fibroblast (HFF) exosomes. Exosome samples included a wide range of concentrations from 100 to 1000 exosomes/µL, and the detection limit of our newly designed system was 117.94 exosome/μL, which was 11 times lower than the previously reported limits. Additionally, exosomes were selectively detected relative to the negative controls, liposomes, and newborn calf serum, confirming that this method prevented non-specific binding. Thus, our study demonstrates that highly sensitive and quantitative exosome detection can be conducted quickly and accurately by using lateral immunochromatographic analysis with M–QD–SNs.

scholarly journals Use of GnRH for Synchronization of the Follicular Wave in Assisted Reproductive Technologies in Sheep: A Preliminary Study

Animals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1208
Author(s):  
Aina Año-Perello ◽  
Zurisaday Santos-Jimenez ◽  
Teresa Encinas ◽  
Paula Martinez-Ros ◽  
Antonio Gonzalez-Bulnes
Keyword(s):  
Luteinizing Hormone ◽  
Assisted Reproductive Technologies ◽  
Ovarian Response ◽  
Reproductive Technologies ◽  
Estrus Synchronization ◽  
Short Term ◽  
Follicular Wave ◽  
Preliminary Study ◽  
Cost Efficient ◽  
Set Up

The present study aimed to set up a short-term protocol for synchronization of follicular wave emergence in sheep, concomitant with estrus synchronization, which would improve ovarian response in assisted reproductive technologies. Administration of a single GnRH dose, concomitant with the insertion of a progesterone-loaded CIDR device, caused regression of gonadotrophin-dependent follicles ≥4 mm in all the GnRH-treated sheep and in around 80% of the controls treated only with CIDR (p < 0.05). Similar percentages of ewes lost all follicles (around 70%) or only the largest one (around 30%) in both groups. Hence, 54.1% and 70% of the sheep lost all large follicles and initiated a new follicular wave in the control and GnRH groups, respectively (p < 0.05). The remaining sheep showed follicles that were still not dependent of luteinizing hormone (LH). So, in fact, all the sheep had non-dominant follicles after treatment. In conclusion, a treatment including GnRH at CIDR insertion would offer a time- and cost-efficient protocol for inducing follicular turnover and synchronizing a new follicular wave at any stage of the estrous cycle.

High Levels of Bisphenol A and Bisphenol S in Brazilian Thermal Paper Receipts and Estimation of Daily Exposure

2015 ◽  
Vol 78 (18) ◽  
pp. 1181-1188 ◽  
Author(s):  
Bruno Alves Rocha ◽  
Lara Ferreira Azevedo ◽  
Matheus Gallimberti ◽  
Andres Dobal Campiglia ◽  
Fernando Barbosa
Keyword(s):  
Bisphenol A ◽  
Bisphenol S ◽  
Daily Exposure ◽  
Thermal Paper

scholarly journals Laccase Electrochemical Biosensor Based on Graphene-Gold/Chitosan Nanocomposite Film for Bisphenol A Detection

2020 ◽  
Vol 16 (5) ◽  
pp. 570-579
Author(s):  
Fuzi M. Fartas ◽  
Jaafar Abdullah ◽  
Nor A. Yusof ◽  
Yusran Sulaiman ◽  
Mohd I. Saiman ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Electrochemical Biosensor ◽  
Limit Of Detection ◽  
Modified Electrodes ◽  
Electrochemical Performances ◽  
Carbon Electrode ◽  
Screen Printed Carbon Electrode ◽  
Laccase Enzyme ◽  
Bisphenol A Detection ◽  
Screen Printed

Background: Bisphenol A (BPA) is considered one of the most common chemicals that could cause environmental endocrine disrupting. Therefore, there is an increasing demand for simple, rapid and sensitive methods for BPA detection that result from BPA leaching into foods and beverages from storage containers. Herein, a simple laccase electrochemical biosensor was developed for the determination of BPA based on Screen-Printed Carbon Electrode (SPCE) modified graphenegold/ chitosan. The synergic effect of graphene-gold/chitosan nanocomposite as electrode modifier greatly facilitates electron-transfer processes between the electrolyte and laccase enzyme, thus leads to a remarkably improved sensitivity for bisphenol A detection. Methods: In this study, laccase enzyme is immobilized onto the Screen-Printed Carbon Electrode (SPCE) modified Graphene-Decorated Gold Nanoparticles (Gr-AuNPs) with Chitosan (Chit). The surface structure of nanocomposite was studied using different techniques including Field Emission Scanning Microscopy (FESEM), TRANSMISSION Electron Microscopy (TEM), Raman spectroscopy and Energy Dispersive X-ray (EDX). Meanwhile, the electrochemical performances of the modified electrodes were studied using Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV). Results: The developed laccase biosensor offered excellent analytical performance for the detection of BPA with a sensitivity of 0.271 μA/μM and Limit of Detection (LOD) of 0.023 μM, respectively. Moreover, the constructed biosensor showed good reproducibility, selectivity and stability towards BPA. The sensor has been used to detect BPA in a different type of commercial plastic products as a real sample and satisfactory result was obtained when compared with the HPLC method. Conclusion: The proposed electrochemical laccase biosensor exhibits good result which is considered as a promising candidate for a simple, rapid and sensitive method especially in the resource- limited condition.

scholarly journals Surface Epitope Coverage Affects Binding Characteristics of Bisphenol-A Functionalized Nanoparticles in a Competitive Inhibition Assay

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Yang Lu ◽  
Joshua Richard Peterson ◽  
Erwann Luais ◽  
John Justin Gooding ◽  
Nanju Alice Lee
Keyword(s):  
Bisphenol A ◽  
Binding Sites ◽  
Competitive Inhibition ◽  
Limit Of Detection ◽  
Molar Concentration ◽  
Inhibition Assay ◽  
Binding Characteristics ◽  
Sensor Performance ◽  
Reliable Detection ◽  
Minimum Number

The biomolecule interface is a key element in immunosensor fabrication, which can greatly influence the sensor performance. This paper explores the effects of surface epitope coverage of small molecule functionalized nanoparticle on the apparent affinity (avidity) of antibody in a competitive inhibition assay using bisphenol-A (BPA) as a model target. An unconventional two-antibody competitive inhibition ELISA (ci-ELISA) using thiolated BPA modified gold nanoparticles (cysBPAv-AuNP) as a competing reagent was devised for this study. It was shown that the antibody complexation with cysBPAv-AuNPs required a minimum number of surface epitopes on the nanoparticle to form a sufficiently strong interaction and reliable detection. The binding of cysBPAv-AuNP to anti-BPA antibodies, for limited antibody binding sites, was enhanced by a greater number of epitope-modified nanoparticles (cysBPAv-AuNP) as well as with higher epitope coverage. Increasing the molar concentration of epitope present in an assay enhanced the binding between anti-BPA antibodies and cysBPAv-AuNP. This implies that, to increase the limit of detection of a competitive inhibition assay, a reduced molar concentration of epitope should be applied. This could be achieved by either lowering the epitope coverage on each cysBPAv-AuNP or the assay molar concentration of cysBPAv-AuNP or both of these factors.

Gold nanoparticle-dotted, ionic liquid-functionalised, carbon hybrid material for ultra-sensitive detection of bisphenol A

2017 ◽  
Vol 14 (6) ◽  
pp. 385
Author(s):  
Yu Tian ◽  
Jianbo Li ◽  
Yanhui Wang ◽  
Chaofan Ding ◽  
Yuanling Sun ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Carboxylic Acid ◽  
Bisphenol A ◽  
Electrochemical Sensor ◽  
Water Solubility ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Hybrid Nanocomposites ◽  
Sensitive Detection ◽  
Endocrine Disorders

Environmental contextBisphenol A, an important industrial material widely used as a plasticiser, fire retardant and resin polymer material, can cause endocrine disorders and precocious puberty. We developed a portable and efficient method for determining bisphenol A, and apply it to the detection of bisphenol A in bottles for infants and young children. AbstractA highly effective electrochemical sensor was developed for the highly sensitive detection of bisphenol A (BPA). The sensor is based on a glassy carbon electrode modified with a composite comprising 1-butyl-3-methyl imidazole hydrobromide (an ionic liquid, IL)-functionalised grapheme oxide (GO) to which gold nanoparticles (AuNPs) and carboxylic acid-functionalised carbon nanotubes (CNT) were absorbed. The negatively charged carboxylic acid-functionalised CNTs and AuNPs are adsorbed on the positively charged GO-IL composite film by electrostatic adsorption. The as-prepared GO-IL-CNT-AuNP hybrid nanocomposites exhibit excellent water solubility owing to the high hydrophilicity of the GO-IL components. Moreover, the excellent conductivity is attributed to the good conductivity of the IL, CNT and AuNP components. The hydrid materials enhance the preconcentration efficiency of BPA and accelerate the electron transfer rate at the electrode–electrolyte interface, as such the resultant fabricated electrochemical sensor displays a fast, stable and sensitive detection performance for trace amounts of BPA. Differential pulse voltammetry was used as a sensitive analytical method for the determination of BPA, and a much wider linear dynamic range of BPA determination was found between 5 and 100nM. The limit of detection for BPA was found down to 1.5nM based on a signal to nose ratio of 3. The modified electrode was successfully employed to detect BPA extracted from a plastic water bottle and milk carton.

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