Label-free detection of fibrinogen based on the fibrinogen-enhanced peroxidase activity of a fibrinogen–hemin composite

The Analyst ◽  
2018 ◽  
Vol 143 (3) ◽  
pp. 725-730 ◽  
Author(s):  
Tingting Hou ◽  
Yuanfu Zhang ◽  
Tao Wu ◽  
Meifeng Wang ◽  
Yinghong Zhang ◽  
...  
Keyword(s):  
Peroxidase Activity ◽  
Colorimetric Method ◽  
Label Free ◽  
Label Free Detection

A simple, label-free colorimetric method for the determination of fibrinogen (Fib) in plasma is presented.

Label-free determination of adenosine and mercury ions according to force mapping-based force-to-color variety

The Analyst ◽  
2018 ◽  
Vol 143 (18) ◽  
pp. 4400-4407 ◽  
Author(s):  
Qing Li ◽  
Gang Wei
Keyword(s):  
Label Free ◽  
Mercury Ions ◽  
Label Free Detection ◽  
Force Mapping

Force mapping can be used as a novel force-to-color sensing technique for the label-free detection of adenosine and Hg2+.

scholarly journals Direct and Competitive Optical Grating Immunosensors for Determination of Fusarium Mycotoxin Zearalenone

Toxins ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 43
Author(s):  
Inna Székács ◽  
Nóra Adányi ◽  
István Szendrő ◽  
András Székács
Keyword(s):  
Environmental Safety ◽  
Detection Methods ◽  
Label Free ◽  
Detection Range ◽  
Fusarium Mycotoxin ◽  
Label Free Detection ◽  
Optical Grating ◽  
Covalent Immobilisation ◽  
Magnitude Improvement

Novel optical waveguide lightmode spectroscopy (OWLS)-based immunosensor formats were developed for label-free detection of Fusarium mycotoxin zearalenone (ZON). To achieve low limits of detection (LODs), both immobilised antibody-based (direct) and immobilised antigen-based (competitive) assay setups were applied. Immunoreagents were immobilised on epoxy-, amino-, and carboxyl-functionalised sensor surfaces, and by optimising the immobilisation methods, standard sigmoid curves were obtained in both sensor formats. An outstanding LOD of 0.002 pg/mL was obtained for ZON in the competitive immunosensor setup with a dynamic detection range between 0.01 and 1 pg/mL ZON concentrations, depending on the covalent immobilisation method applied. This corresponds to a five orders of magnitude improvement in detectability of ZON relative to the previously developed enzyme-linked immonosorbent assay (ELISA) method. The selectivity of the immunosensor for ZON was demonstrated with structural analogues (α-zearalenol, α-zearalanol, and β-zearalanol) and structurally unrelated mycotoxins. The method was found to be applicable in maize extract using acetonitrile as the organic solvent, upon a dilution rate of 1:10,000 in buffer. Thus, the OWLS immunosensor method developed appears to be suitable for the quantitative determination of ZON in aqueous medium. The new technique can widen the range of sensoric detection methods of ZON for surveys in food and environmental safety assessment.

scholarly journals Chiral Hybrid Nanosystems and Their Biosensing Applications

2020 ◽  
Author(s):  
Vladimir E. Bochenkov ◽  
Tatyana I. Shabatina
Keyword(s):  
Refractive Index ◽  
Electric Fields ◽  
Metal Nanostructures ◽  
Order Structure ◽  
Molecular Adsorption ◽  
Label Free ◽  
Label Free Detection ◽  
Hybrid Nanosystems ◽  
Local Refractive Index

The presented chapter is devoted to chiral biosensing using various metal nanostructures and their hybrid nanosystems with optically active bio- and organic molecules. Plasmonic nanosystems and nanostructures provide an excellent platform for label-free detection of molecular adsorption by detecting tiny changes in the local refractive index or amplification of light-induced processes in biomolecules. Based on recent theoretical and experimental developments in plasmon-enhanced local electric fields, we consider the main types of molecular-plasmonic hybrid systems capable of generating an amplified chiroptical signal for such applications as detecting the presence of certain biomolecules and (in some cases) determination of their orientation and higher-order structure.

Ultrasensitive and label-free detection of creatine based on CdO nanoparticles: a real sample approach

2017 ◽  
Vol 41 (14) ◽  
pp. 6667-6677 ◽  
Author(s):  
Mohammed M. Rahman ◽  
Mohammad Musarraf Hussain ◽  
Abdullah M. Asiri
Keyword(s):  
Dynamic Range ◽  
Limit Of Detection ◽  
Cadmium Oxide ◽  
Real Sample ◽  
Label Free ◽  
Long Term Stability ◽  
Label Free Detection ◽  
Cdo Nanoparticles ◽  
Low Dimensional

Low-dimensional cadmium oxide nanoparticles (CdO NPs) were prepared by a facile wet-chemical method, which later electrochemically investigated for the determination of selective creatine and measured the analytical sensor parameters such as sensitivity, limit of detection (LOD), linear dynamic range (LDR), long-term stability, and real-sample validation.

Label-free detection of cytochrome C by a conducting polymer-based impedimetric screen-printed aptasensor

2018 ◽  
Vol 42 (8) ◽  
pp. 6034-6039 ◽  
Author(s):  
Atefeh Shafaat ◽  
Farnoush Faridbod ◽  
Mohammad Reza Ganjali
Keyword(s):  
Cytochrome C ◽  
Conducting Polymer ◽  
Cell Apoptosis ◽  
Label Free ◽  
Label Free Detection ◽  
Screen Printed

In this study we have introduced a new sensitive and selective biosensor for the determination of cytochrome C (Cyt C) as a biomarker for cell apoptosis.

The Need for Using An Enzymatic Colorimetric Assay in Creatinine Determination of Peritoneal Dialysis Solutions

1990 ◽  
Vol 10 (1) ◽  
pp. 89-92 ◽  
Author(s):  
Liliane Larpent ◽  
Christian Verger
Keyword(s):  
Peritoneal Dialysis ◽  
Reliable Method ◽  
Colorimetric Assay ◽  
Colorimetric Method ◽  
Peritoneal Membrane ◽  
Creatinine Kinetics ◽  
Dialysis Solutions ◽  
Peritoneal Dialysis Solutions ◽  
Enzymatic Test

The fate of the peritoneal membrane on continuous ambulatory peritoneal dialysis (CAPD) is usually evaluated through the modification of its permeability to various solutes as glucose, creatinine, and urea. Therefore, the accuracy of the methods used for measurements of creatinine is of great importance. A particular problem does exist for creatinine determination as it may be influenced by the presence of glucose. We studied a new enzymatic colorimetric method for creatinine determination in peritoneal dialysis solutions which contain high dextrose concentrations. Creatinine was measured in plasma, urine, and dialysate from 18 patients on CAPD and in pure dextrose solutions, with an enzymatic test (Boehringer Mannheim) and with Jaffe's reaction on two different analyzers: Astra (Beckman) and Eris (Merck). Creatinine results were similar with both assays (Jaffe's reaction and enzymatic test) when measured in blood and urine. However the Jaffe's reaction gave higher creatinine results than the enzymatic test (p < 0.001), when assays were performed in peritoneal dialysis solutions and in pure glucose solutions. In addition, it appeared that other components of dialysis solutions, mainly calcium chloride, influenced unpredictably the results of creatinine with the Jaffe's reaction. We conclude that specific enzymatic test is a more accurate and reliable method to evaluate creatinine kinetics through the peritoneal membrane when determined in CAPD solutions.

scholarly journals The Role of Surface Chemistry in the Efficacy of Protein and DNA Microarrays for Label-Free Detection: An Overview

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1026
Author(s):  
Elisa Chiodi ◽  
Allison M. Marn ◽  
Matthew T. Geib ◽  
M. Selim Ünlü
Keyword(s):  
Surface Chemistry ◽  
Surface Functionalization ◽  
Dna Microarrays ◽  
Label Free ◽  
Polymeric Coatings ◽  
Label Free Detection ◽  
Particle Imaging ◽  
Single Particle Imaging ◽  
The Impact

The importance of microarrays in diagnostics and medicine has drastically increased in the last few years. Nevertheless, the efficiency of a microarray-based assay intrinsically depends on the density and functionality of the biorecognition elements immobilized onto each sensor spot. Recently, researchers have put effort into developing new functionalization strategies and technologies which provide efficient immobilization and stability of any sort of molecule. Here, we present an overview of the most widely used methods of surface functionalization of microarray substrates, as well as the most recent advances in the field, and compare their performance in terms of optimal immobilization of the bioreceptor molecules. We focus on label-free microarrays and, in particular, we aim to describe the impact of surface chemistry on two types of microarray-based sensors: microarrays for single particle imaging and for label-free measurements of binding kinetics. Both protein and DNA microarrays are taken into consideration, and the effect of different polymeric coatings on the molecules’ functionalities is critically analyzed.

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