scholarly journals A tandem giant magnetoresistance assay for one-shot quantification of clinically relevant concentrations of N-terminal pro-B-type natriuretic peptide in human blood

2021 ◽  
Author(s):  
Fanda Meng ◽  
Weisong Huo ◽  
Jie Lian ◽  
Lei Zhang ◽  
Xizeng Shi ◽  
...  
Keyword(s):  
Detection Limit ◽  
Giant Magnetoresistance ◽  
Dynamic Range ◽  
Point Of Care ◽  
Sample Volume ◽  
Small Sample ◽  
Broad Dynamic Range ◽  
Gmr Sensors ◽  
Gmr Sensor ◽  
Sample Volume Requirement

AbstractWe report a microfluidic sandwich immunoassay constructed around a dual-giant magnetoresistance (GMR) sensor array to quantify the heart failure biomarker NT-proBNP in human plasma at the clinically relevant concentration levels between 15 pg/mL and 40 ng/mL. The broad dynamic range was achieved by differential coating of two identical GMR sensors operated in tandem, and combining two standard curves. The detection limit was determined as 5 pg/mL. The assay, involving 53 plasma samples from patients with different cardiovascular diseases, was validated against the Roche Cobas e411 analyzer. The salient features of this system are its wide concentration range, low detection limit, small sample volume requirement (50 μL), and the need for a short measurement time of 15 min, making it a prospective candidate for practical use in point of care analysis.

scholarly journals Luciferase Immunoprecipitation Systems immunoassay is a sensitive, rapid method to detect allergen component-specific IgE

2020 ◽  
Author(s):  
Adora A. Lin ◽  
Natalia S. Perez ◽  
Pamela A. Frischmeyer-Guerrerio ◽  
Thomas B. Nutman
Keyword(s):  
Dynamic Range ◽  
Specific Ige ◽  
Turnaround Time ◽  
Sample Volume ◽  
Small Sample ◽  
Flexible Tool ◽  
Allergen Component ◽  
Fel D 1 ◽  
Broad Dynamic Range ◽  
Allergen Extracts

AbstractCurrent assays to detect allergen-specific IgE have constraints related to obtaining pure, conformationally active allergen, variability in allergen extracts, sample volume required, and turnaround time. The luciferase immunoprecipitation systems (LIPS) immunoassay is a fast, sensitive assay created using recombinant antigens that requires a low specimen volume. These assays can also be easily modified to detect multiple antigens and antibody isotypes. Here, we demonstrate the use of LIPS assays as an innovative method to quantitatively measure allergen component-specific IgE in small sample volumes. Sera from healthy volunteers, helminth-infected adults, and peanut-allergic children were screened for IgE to cat using ImmunoCAP. These samples were also measured for IgE against Fel d 1 using LIPS. LIPS signal correlated to cat IgE levels with rS = 0.6204, p < 0.001. The LIPS signal: noise ratio differed significantly between cat IgE-samples and cat IgE+ samples with values > 0.5 kU/L, with the ability to differentiate cat IgE – individuals from cat IgE+ individuals with 85% sensitivity and 76% specificity. Given their rapidity, efficiency, sensitivity, and quantitation over a broad dynamic range, LIPS immunoassays can be a robust and flexible tool with potential uses in allergy research, diagnostics, and treatment.

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 Multitarget, quantitative nanoplasmonic electrical field-enhanced resonating device (NE2RD) for diagnostics

2015 ◽  
Vol 112 (32) ◽  
pp. E4354-E4363 ◽  
Author(s):  
Fatih Inci ◽  
Chiara Filippini ◽  
Murat Baday ◽  
Mehmet Ozgun Ozen ◽  
Semih Calamak ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Point Of Care ◽  
Medical Diagnostics ◽  
Clinical Samples ◽  
Label Free ◽  
Protein Biomarkers ◽  
Electrical Field ◽  
Color Changes ◽  
Sensing Platform ◽  
Broad Dynamic Range

Recent advances in biosensing technologies present great potential for medical diagnostics, thus improving clinical decisions. However, creating a label-free general sensing platform capable of detecting multiple biotargets in various clinical specimens over a wide dynamic range, without lengthy sample-processing steps, remains a considerable challenge. In practice, these barriers prevent broad applications in clinics and at patients’ homes. Here, we demonstrate the nanoplasmonic electrical field-enhanced resonating device (NE2RD), which addresses all these impediments on a single platform. The NE2RD employs an immunodetection assay to capture biotargets, and precisely measures spectral color changes by their wavelength and extinction intensity shifts in nanoparticles without prior sample labeling or preprocessing. We present through multiple examples, a label-free, quantitative, portable, multitarget platform by rapidly detecting various protein biomarkers, drugs, protein allergens, bacteria, eukaryotic cells, and distinct viruses. The linear dynamic range of NE2RD is five orders of magnitude broader than ELISA, with a sensitivity down to 400 fg/mL This range and sensitivity are achieved by self-assembling gold nanoparticles to generate hot spots on a 3D-oriented substrate for ultrasensitive measurements. We demonstrate that this precise platform handles multiple clinical samples such as whole blood, serum, and saliva without sample preprocessing under diverse conditions of temperature, pH, and ionic strength. The NE2RD’s broad dynamic range, detection limit, and portability integrated with a disposable fluidic chip have broad applications, potentially enabling the transition toward precision medicine at the point-of-care or primary care settings and at patients’ homes.

scholarly journals Automated HPLC screening of newborns for sickle cell anemia and other hemoglobinopathies

1996 ◽  
Vol 42 (5) ◽  
pp. 704-710 ◽  
Author(s):  
J W Eastman ◽  
R Wong ◽  
C L Liao ◽  
D R Morales
Keyword(s):  
Quality Control ◽  
Detection Limit ◽  
Sickle Cell Anemia ◽  
Sample Volume ◽  
Small Sample ◽  
Peak Resolution ◽  
Automated Hplc ◽  
Hb S ◽  
Blood Spot ◽  
Small Sample Volume

Abstract Automated HPLC is used to test dried blood-spot specimens from newborns for hemoglobins (Hb) F, A, S, C, E, and D. We present the method and report on its performance determined during &gt;4 years of testing 2.5 x 10(6) newborns. The method features automated derivation of presumptive phenotypes; quantitative quality control and proficiency testing; throughput of one specimen per minute; small sample volume; hemoglobin concentrations quantified with an interlaboratory CV of 14-18%; retention times with interlaboratory CV of &lt;2% and matching, within +/- 0.03 min, of laboratories and reagent lots; control of peak resolution; 0.5% detection limit for Hb S and C, and 1.0% for Hb F, A, E, and D; few interferences; and negligible background and carryover. Shortcomings of the method are the absence of microplate barcode identification and the need for manually pipetting the sample eluate into the microplate.

scholarly journals Evaluation of In-Flow Magnetoresistive Chip Cell—Counter as a Diagnostic Tool

Biosensors ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 105 ◽  
Author(s):  
Manon Giraud ◽  
François-Damien Delapierre ◽  
Anne Wijkhuisen ◽  
Pierre Bonville ◽  
Mathieu Thévenin ◽  
...  
Keyword(s):  
Giant Magnetoresistance ◽  
Limit Of Detection ◽  
Malignant Cell ◽  
Elisa Test ◽  
Great Sensitivity ◽  
Actual System ◽  
Whole Cells ◽  
Gmr Sensors ◽  
Gmr Sensor ◽  
Sensor Detection

Inexpensive simple medical devices allowing fast and reliable counting of whole cells are of interest for diagnosis and treatment monitoring. Magnetic-based labs on a chip are one of the possibilities currently studied to address this issue. Giant magnetoresistance (GMR) sensors offer both great sensitivity and device integrability with microfluidics and electronics. When used on a dynamic system, GMR-based biochips are able to detect magnetically labeled individual cells. In this article, a rigorous evaluation of the main characteristics of this magnetic medical device (specificity, sensitivity, time of use and variability) are presented and compared to those of both an ELISA test and a conventional flow cytometer, using an eukaryotic malignant cell line model in physiological conditions (NS1 murine cells in phosphate buffer saline). We describe a proof of specificity of a GMR sensor detection of magnetically labeled cells. The limit of detection of the actual system was shown to be similar to the ELISA one and 10 times higher than the cytometer one.

Biosensor Based on Giant Magnetoresistance Material

2010 ◽  
Vol 1 (3) ◽  
pp. 1-15 ◽  
Author(s):  
Mitra Djamal
Keyword(s):  
Giant Magnetoresistance ◽  
Large Scale ◽  
Single Chip ◽  
Biomolecule Detection ◽  
Novel Approach ◽  
Large Scale Integration ◽  
Gmr Sensors ◽  
Gmr Sensor ◽  
Scale Integration ◽  
The Magnetic Field

In recent years, giant magnetoresistance (GMR) sensors have shown a great potential as sensing elements for biomolecule detection. The resistance of a GMR sensor changes with the magnetic field applied to the sensor, so that a magnetically labeled biomolecule can induce a signal. Compared with the traditional optical detection that is widely used in biomedicine, GMR sensors are more sensitive, portable, and give a fully electronic readout. In addition, GMR sensors are inexpensive and the fabrication is compatible with the current VLSI (Very Large Scale Integration) technology. In this regard, GMR sensors can be easily integrated with electronics and microfluidics to detect many different analytes on a single chip. In this article, the authors demonstrate a comprehensive review on a novel approach in biosensors based on GMR material.

Giant Magnetoresistance Imaging for NDE of Conductive Materials

1999 ◽  
Vol 591 ◽  
Author(s):  
E. S. Boltz ◽  
S. G. Albanna ◽  
A. R. Stallings ◽  
Y. H. Spooner ◽  
J. P. Abeyta
Keyword(s):  
Eddy Current ◽  
Giant Magnetoresistance ◽  
High Spatial Resolution ◽  
Low Frequency ◽  
High Sensitivity ◽  
Low Noise ◽  
Conductive Materials ◽  
Gmr Sensors ◽  
Current Sensors ◽  
Gmr Sensor

ABSTRACTTraditional coil-based eddy-current sensors are severely limited in their ability to detect small buried defects, defects under fasteners and deeply buried cracks and corrosion. TPL has developed eddy-current sensors and arrays based on the use of Giant Magnetoresistance (GMR) sensor elements. GMR offers high sensitivity, very wide bandwidth and low noise from DC to over 1 GHz. Coupled with the ability to fabricate GMR sensors with micron-level dimensions, these new eddy-current sensors offer an ideal technology for inspections requiring high spatial resolution and low-frequency, deeply-penetrating fields.

scholarly journals Label-Free Optical Resonator-Based Biosensors

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5901
Author(s):  
Donggee Rho ◽  
Caitlyn Breaux ◽  
Seunghyun Kim
Keyword(s):  
Point Of Care ◽  
Health And Safety ◽  
Disease Diagnosis ◽  
Medical Diagnostics ◽  
Sample Volume ◽  
Small Sample ◽  
Optical Resonator ◽  
Future Research ◽  
Label Free ◽  
Label Free Detection

The demand for biosensor technology has grown drastically over the last few decades, mainly in disease diagnosis, drug development, and environmental health and safety. Optical resonator-based biosensors have been widely exploited to achieve highly sensitive, rapid, and label-free detection of biological analytes. The advancements in microfluidic and micro/nanofabrication technologies allow them to be miniaturized and simultaneously detect various analytes in a small sample volume. By virtue of these advantages and advancements, the optical resonator-based biosensor is considered a promising platform not only for general medical diagnostics but also for point-of-care applications. This review aims to provide an overview of recent progresses in label-free optical resonator-based biosensors published mostly over the last 5 years. We categorized them into Fabry-Perot interferometer-based and whispering gallery mode-based biosensors. The principles behind each biosensor are concisely introduced, and recent progresses in configurations, materials, test setup, and light confinement methods are described. Finally, the current challenges and future research topics of the optical resonator-based biosensor are discussed.

scholarly journals Microfluidic Overhauser DNP Chip for Signal-enhanced Compact NMR

2020 ◽  
Author(s):  
Sebastian Kiss ◽  
Neil MacKinnon ◽  
Jan Korvink
Keyword(s):  
Point Of Care ◽  
Power Level ◽  
Sample Volume ◽  
Spectroscopic Technique ◽  
Small Sample ◽  
Biomarker Detection ◽  
Low Field ◽  
Equilibrium Level ◽  
Microwave Power Level

Abstract Nuclear magnetic resonance at low field strength is an insensitive spectroscopic technique, precluding portable applications with small sample volumes, such as needed for biomarker detection in body fluids. Here we report a compact double resonant chip stack system that implements in situ dynamic nuclear polarisation of a 130 nL sample volume, achieving a signal enhancement of 54 w.r.t. the thermal equilibrium level at a microwave power level of 0.5W. This work overcomes instrumental barriers to the use of NMR detection for point-of-care applications.

Protein biochip systems for the clinical laboratory

2005 ◽  
Vol 43 (12) ◽  
Author(s):  
Anne Marie Dupuy ◽  
Sylvain Lehmann ◽  
Jean Paul Cristol
Keyword(s):  
Clinical Laboratory ◽  
Point Of Care ◽  
Sample Volume ◽  
Small Sample ◽  
Throughput Capacity ◽  
Great Promise ◽  
Current Trends ◽  
Biomedical Diagnosis ◽  
Multiplexed Immunoassay ◽  
Spotted Array

AbstractClassical methods of protein analysis such as electrophoresis, ELISA and liquid chromatography are generally time-consuming, labor-intensive and lack high-throughput capacity. In addition, all existing methods used to measure proteins necessitate multiple division of the original sample and individual tests carried out for each substance, with an associated cost for each test. The chip system allows several tests to be performed simultaneously without dividing the original patient sample. This system facilitates the development of multiplexed assays that simultaneously measure many different analytes in a small sample volume. These emerging technologies fall into two categories: 1) spotted array-based tools, and 2) microfluidic-based tools. Miniaturized and multiplexed immunoassays allow a great deal of information to be obtained from a single sample. These analytical systems are referred to as “lab-on-a-chip” devices. This article presents current trends and advances in miniaturized multiplexed immunoassay technologies, reviewing different systems from research to point-of-care assays. We focus on a subset of chip-based assays that may be used in a clinical laboratory and are directly applicable for biomedical diagnosis. Recent advances in biochip assays combine the power of miniaturization, microfluidics, micro- to nanoparticles, and quantification. A number of applications are just beginning to be explored. The power of biochip assays offers great promise for point-of-care clinical testing and monitoring of many important analytes.

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