scholarly journals Microfluidic Overhauser DNP chip for signal-enhanced compact NMR

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sebastian Z. Kiss ◽  
Neil MacKinnon ◽  
Jan G. Korvink
Keyword(s):  
Point Of Care ◽  
Power Level ◽  
Sample Volume ◽  
Spectroscopic Technique ◽  
Small Sample ◽  
Biomarker Detection ◽  
Low Field ◽  
Equilibrium Level ◽  
Microwave Power Level

AbstractNuclear 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 signal enhancements of up to − 60 w.r.t. the thermal equilibrium level at a microwave power level of 0.5 W. This work overcomes instrumental barriers to the use of NMR detection for point-of-care applications.

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.

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 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 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.

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.

scholarly journals Clustering NMR: Machine learning assistive rapid (pseudo) two-dimensional relaxometry mapping

2020 ◽  
Author(s):  
Weng Kung Peng
Keyword(s):  
Machine Learning ◽  
Signal To Noise Ratio ◽  
Point Of Care ◽  
Object Classification ◽  
New Class ◽  
Low Field ◽  
Nmr Relaxometry ◽  
Repetition Time ◽  
Oil Gas

AbstractLow-field nuclear magnetic resonance (NMR) relaxometry is an attractive approach for point-of-care testing medical diagnosis, industrial food science, and in situ oil-gas exploration. One of the problem however is, the inherently long relaxation time of the (liquid) sample, (and hence low signal-to-noise ratio) causes unnecessarily long repetition time. In this work, we present a new class of methodology for rapid and accurate object classification using NMR relaxometry with the aid of machine learning. We demonstrate that the sensitivity and specificity of the classification is substantially improved with higher order of (pseudo)-dimensionality (e.g., 2D or multidimensional). This new methodology (termed as Clustering NMR) is extremely useful for rapid and accurate object classification (in less than a minute) using the low-field NMR.

scholarly journals Point-of-Care Compatibility of Ultra-Sensitive Detection Techniques for the Cardiac Biomarker Troponin I—Challenges and Potential Value

Biosensors ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 114 ◽  
Author(s):  
Brian Regan ◽  
Richard O’Kennedy ◽  
David Collins
Keyword(s):  
Troponin I ◽  
Point Of Care ◽  
Well Being ◽  
Small Sample ◽  
Cardiac Biomarkers ◽  
Sensitive Detection ◽  
Biomarker Detection ◽  
Cardiac Biomarker ◽  
Detection Techniques ◽  
Cardiac Symptoms

Cardiac biomarkers are frequently measured to provide guidance on the well-being of a patient in relation to cardiac health with many assays having been developed and widely utilised in clinical assessment. Effectively treating and managing cardiovascular disease (CVD) relies on swiftly responding to signs of cardiac symptoms, thus providing a basis for enhanced patient management and an overall better health outcome. Ultra-sensitive cardiac biomarker detection techniques play a pivotal role in improving the diagnostic capacity of an assay and thus enabling a better-informed decision. However, currently, the typical approach taken within healthcare depends on centralised laboratories performing analysis of cardiac biomarkers, thus restricting the roll-out of rapid diagnostics. Point-of-care testing (POCT) involves conducting the diagnostic test in the presence of the patient, with a short turnaround time, requiring small sample volumes without compromising the sensitivity of the assay. This technology is ideal for combatting CVD, thus the formulation of ultra-sensitive assays and the design of biosensors will be critically evaluated, focusing on the feasibility of these techniques for point-of-care (POC) integration. Moreover, there are several key factors, which in combination, contribute to the development of ultra-sensitive techniques, namely the incorporation of nanomaterials for sensitivity enhancement and manipulation of labelling methods. This review will explore the latest developments in cardiac biomarker detection, primarily focusing on the detection of cardiac troponin I (cTnI). Highly sensitive detection of cTnI is of paramount importance regarding the rapid rule-in/rule-out of acute myocardial infarction (AMI). Thus the challenges encountered during cTnI measurements are outlined in detail to assist in demonstrating the drawbacks of current commercial assays and the obstructions to standardisation. Furthermore, the added benefits of introducing multi-biomarker panels are reviewed, several key biomarkers are evaluated and the analytical benefits provided by multimarkers-based methods are highlighted.

scholarly journals Single Step In Situ Detection of Surface Protein and MicroRNA in Clustered Extracellular Vesicles Using Flow Cytometry

2021 ◽  
Vol 10 (2) ◽  
pp. 319
Author(s):  
Hee Cheol Yang ◽  
Won Jong Rhee
Keyword(s):  
Extracellular Vesicles ◽  
Liquid Biopsy ◽  
Molecular Beacon ◽  
Disease Diagnosis ◽  
Single Step ◽  
Flow Cytometer ◽  
Surface Proteins ◽  
Biomarker Detection ◽  
In Situ Detection

Because cancers are heterogeneous, it is evident that multiplexed detection is required to achieve disease diagnosis with high accuracy and specificity. Extracellular vesicles (EVs) have been a subject of great interest as sources of novel biomarkers for cancer liquid biopsy. However, EVs are nano-sized particles that are difficult to handle; thus, it is necessary to develop a method that enables efficient and straightforward EV biomarker detection. In the present study, we developed a method for single step in situ detection of EV surface proteins and inner miRNAs simultaneously using a flow cytometer. CD63 antibody and molecular beacon-21 were investigated for multiplexed biomarker detection in normal and cancer EVs. A phospholipid-polymer-phospholipid conjugate was introduced to induce clustering of the EVs analyzed using nanoparticle tracking analysis, which enhanced the detection signals. As a result, the method could detect and distinguish cancer cell-derived EVs using a flow cytometer. Thus, single step in situ detection of multiple EV biomarkers using a flow cytometer can be applied as a simple, labor- and time-saving, non-invasive liquid biopsy for the diagnosis of various diseases, including cancer.

Comparison of 2 glucose analytical methodologies in immature Kemp’s ridley sea turtles: dry chemistry of plasma versus point-of-care glucometer analysis of whole blood

2021 ◽  
pp. 104063872110018
Author(s):  
Justin R. Perrault ◽  
Michael D. Arendt ◽  
Jeffrey A. Schwenter ◽  
Julia L. Byrd ◽  
Kathryn A. Tuxbury ◽  
...  
Keyword(s):  
Whole Blood ◽  
Point Of Care ◽  
Sea Turtles ◽  
Sample Volume ◽  
Specific Reference ◽  
Volume Data ◽  
Analytical Methodology ◽  
Glucose Determination ◽  
Kemp's Ridley Sea Turtles ◽  
Kemp's Ridley

Blood glucose measurements provide important diagnostic information regarding stress, disease, and nutritional status. Glucose analytical methodologies include dry chemistry analysis (DCA) of plasma and point-of-care (POC) glucometer analysis of whole blood; however, these 2 methods differ in cost, required sample volume, and processing time. Because POC glucometers use built-in equations based on features of mammalian blood to convert whole blood measurements to plasma equivalent units, obtained glucose data must be compared and validated using gold-standard chemistry analytical methodology in reptiles. For in-water, trawl-captured, immature Kemp’s ridley sea turtles ( Lepidochelys kempii) from Georgia, USA, we observed significant, positive agreement between the 2 glucose determination methods; however, the glucometer overestimated glucose concentrations by 1.4 mmol/L on average in comparison to DCA and produced a wider range of results. The discordance of these results suggests that POC glucometer glucose data should be interpreted in the context of methodology- and brand-specific reference intervals along with concurrent packed cell volume data.

Sign in / Sign up

Export Citation Format

Share Document