scholarly journals A Simple, Low Cost, Sensitive, and Portable Electrochemical Immunochromatography Sensing Device to Measure Estrone-3-Sulfate

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4781
Author(s):  
Wataru Iwasaki ◽  
Chiwa Kataoka ◽  
Kazuyuki Sawadaishi ◽  
Keitaro Suyama ◽  
Nobutomo Morita ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Electrochemical Techniques ◽  
Low Molecular Weight ◽  
Nitrocellulose Membrane ◽  
Electrochemical Detector ◽  
Simple Method ◽  
Endogenous Steroids

In livestock production, point-of-care testing (POCT) technology that enables easy on-site analysis of sex hormones is desired to improve reproductive efficiency. In this context, low-molecular-weight endogenous steroids are particularly important for perinatal management. Therefore, we attempted to use a simple method that combines electrochemical techniques with immunochromatography to measure estrone-3-sulfate (E1S), one of the low-molecular-weight endogenous steroids that is an estrogen ester. The limit of detection (LOD) for E1S achieved by electrochemical immunochromatography was 570.5 ng/mL, which was one to two orders of magnitude lower than that of small molecule compounds analyzed by other POCT techniques (Primpray et al., Anal. Chim. Acta, 2019). In addition, it was indicated by a colorimetric analysis that the sensitivity of the electrochemical immunochromatographic technique could be enhanced by improving the method of application of the antibodies on the nitrocellulose membrane and the contact between the electrochemical detector and the nitrocellulose membrane.

scholarly journals Rapid and Sensitive Detection of miRNA Based on AC Electrokinetic Capacitive Sensing for Point-of-Care Applications

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3985
Author(s):  
Nan Wan ◽  
Yu Jiang ◽  
Jiamei Huang ◽  
Rania Oueslati ◽  
Shigetoshi Eda ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Clinical Diagnostics ◽  
Detection Methods ◽  
Capacitive Sensing ◽  
Application Potential ◽  
Mirna Detection ◽  
Mirna 25 ◽  
Low Sensitivity

A sensitive and efficient method for microRNAs (miRNAs) detection is strongly desired by clinicians and, in recent years, the search for such a method has drawn much attention. There has been significant interest in using miRNA as biomarkers for multiple diseases and conditions in clinical diagnostics. Presently, most miRNA detection methods suffer from drawbacks, e.g., low sensitivity, long assay time, expensive equipment, trained personnel, or unsuitability for point-of-care. New methodologies are needed to overcome these limitations to allow rapid, sensitive, low-cost, easy-to-use, and portable methods for miRNA detection at the point of care. In this work, to overcome these shortcomings, we integrated capacitive sensing and alternating current electrokinetic effects to detect specific miRNA-16b molecules, as a model, with the limit of detection reaching 1.0 femto molar (fM) levels. The specificity of the sensor was verified by testing miRNA-25, which has the same length as miRNA-16b. The sensor we developed demonstrated significant improvements in sensitivity, response time and cost over other miRNA detection methods, and has application potential at point-of-care.

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 Whole Blood Immunoassay Based on Centrifugal Bead Sedimentation

2011 ◽  
Vol 57 (5) ◽  
pp. 753-761 ◽  
Author(s):  
Ulrich Y Schaff ◽  
Greg J Sommer
Keyword(s):  
Whole Blood ◽  
Single Channel ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Microfluidic System ◽  
Blood Samples ◽  
Reactive Protein ◽  
Immunoassay Technique ◽  
Microfluidic Immunoassay

BACKGROUND Centrifugal “lab on a disk” microfluidics is a promising avenue for developing portable, low-cost, automated immunoassays. However, the necessity of incorporating multiple wash steps results in complicated designs that increase the time and sample/reagent volumes needed to run assays and raises the probability of errors. We present proof of principle for a disk-based microfluidic immunoassay technique that processes blood samples without conventional wash steps. METHODS Microfluidic disks were fabricated from layers of patterned, double-sided tape and polymer sheets. Sample was mixed on-disk with assay capture beads and labeling antibodies. Following incubation, the assay beads were physically separated from the blood cells, plasma, and unbound label by centrifugation through a density medium. A signal-laden pellet formed at the periphery of the disk was analyzed to quantify concentration of the target analyte. RESULTS To demonstrate this technique, the inflammation biomarkers C-reactive protein and interleukin-6 were measured from spiked mouse plasma and human whole blood samples. On-disk processing (mixing, labeling, and separation) facilitated direct assays on 1-μL samples with a 15-min sample-to-answer time, <100 pmol/L limit of detection, and 10% CV. We also used a unique single-channel multiplexing technique based on the sedimentation rate of different size or density bead populations. CONCLUSIONS This portable microfluidic system is a promising method for rapid, inexpensive, and automated detection of multiple analytes directly from a drop of blood in a point-of-care setting.

scholarly journals Validation and Application of a Derivatization-Free RP-HPLC-DAD Method for the Determination of Low Molecular Weight Salivary Metabolites

2020 ◽  
Vol 17 (17) ◽  
pp. 6158
Author(s):  
Beatrice Campanella ◽  
Tommaso Lomonaco ◽  
Edoardo Benedetti ◽  
Massimo Onor ◽  
Riccardo Nieri ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Cost ◽  
Reversed Phase ◽  
Low Molecular Weight ◽  
Single Individual ◽  
Sampling Device ◽  
Non Invasive ◽  
Minimal Sample ◽  
Whole Saliva

Saliva is an interesting, non-conventional, valuable diagnostic fluid. It can be collected using standardized sampling device; thus, its sampling is easy and non-invasive, it contains a variety of organic metabolites that reflect blood composition. The aim of this study was to validate a user-friendly method for the simultaneous determination of low molecular weight metabolites in saliva. We have optimized and validated a high throughput, direct, low-cost reversed phase liquid chromatographic method with diode array detection method without any pre- or post-column derivatization. We indexed salivary biomolecules in 35 whole non-stimulated saliva samples collected in 8 individuals in different days, including organic acids and amino acids and other carbonyl compounds. Among these, 16 whole saliva samples were collected by a single individual over three weeks before, during and after treatment with antibiotic in order to investigate the dynamics of metabolites. The concentrations of the metabolites were compared with the literature data. The multianalyte method here proposed requires a minimal sample handling and it is cost-effectiveness as it makes possible to analyze a high number of samples with basic instrumentation. The identification and quantitation of salivary metabolites may allow the definition of potential biomarkers for non-invasive “personal monitoring” during drug treatments, work out, or life habits over time.

scholarly journals SIMPLE METHOD FOR OPTIMIZATION OF HEPARIN AND ENOXAPARIN DETECTION USING AGAROSE GEL ELECTROPHORESIS

2019 ◽  
pp. 12-15
Author(s):  
Ahmad Abdulrahman Almeman
Keyword(s):  
Molecular Weight ◽  
Toluidine Blue ◽  
Gel Electrophoresis ◽  
Optimization Procedure ◽  
Solvent Mixture ◽  
Acid Mixture ◽  
Low Molecular Weight ◽  
Simple Method ◽  
Electrophoresis Method ◽  
Tools And Techniques

Objective: A simple gel electrophoresis method for low-molecular-weight heparins (LMWH) is required for use in a variety of laboratories to allow further identification and purification. This study aimed to optimize the detection of heparin and enoxaparin (low-molecular-weight heparin by gel electrophoresis. Methods: Several gel electrophoresis conditions were tested to optimize the detection of enoxaparin by using a simple method with a modified Volpi’s approach. Multiple gel thicknesses, voltage settings, and enoxaparin concentrations were tested in the optimization procedure. Enoxaparin was purchased from a local supplier as pre-filled pharmaceutical injections. Highly purified 0.5% and 1.0% agarose gels were prepared and a series of enoxaparin concentrations was added to both gels for comparison and optimization. The 0.2% toluidine blue stain was prepared by the addition of 1 ml in an ethanol-water-acetic acid mixture (50:49:1; v/v/w). The staining process comprised two steps: first, toluidine blue was added for 30 min and destained overnight in the solvent mixture. Subsequently, the following morning, the second step was conducted, in which the gel was restained for 30 min with the same concentration of toluidine blue. We continued to stain the gel until the bands were visible. Results: The gel electrophoresis results showed that clearest and sharpest bands were obtained using 65–75 mAh and 85 V settings. At 95 mAh, the bands were slightly washed out. Conclusion: This study successfully facilitated the detection of enoxaparin, a LMWH, and heparin in the laboratory by using simple tools and techniques available in most laboratories.

scholarly journals A simple method for the production of low molecular weight hyaluronan by in situ degradation in fermentation broth

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 477-481
Author(s):  
Jianfeng Mei ◽  
Zhihong Dong ◽  
Yu Yi ◽  
Yanlu Zhang ◽  
Guoqing Ying
Keyword(s):  
Molecular Weight ◽  
Enzymatic Degradation ◽  
Fermentation Broth ◽  
Low Molecular Weight ◽  
Streptococcus Zooepidemicus ◽  
Medium Ph ◽  
Simple Method ◽  
Suitable Temperature ◽  
In Situ Degradation

AbstractFermentation of hyaluronan (HA) by Streptococcus zooepidemicus was carried out in a 10-L fermentor. When the medium pH was controlled at 7.0 and the temperature was maintained at 38°C for 12 h followed by 35°C for 8 h, the yield of HA was 4.83 g/L with a molecular weight of 1,890 kDa. After the cells were removed by centrifugation from the fermentation broth, HA was slowly degraded to low molecular weight HA by hyaluronidase at a suitable temperature without a decrease in HA concentration. If the time and temperature for enzymatic degradation were controlled, the desired low molecular weight HA could be obtained by in situ degradation in the fermentation broth. The method does not require the addition of exogenous hyaluronidase, and is a simple way to produce low molecular weight HA.

scholarly journals Application of Flexible Display Technology to Low Cost Multiplexed Point-of-Care Medical Diagnostic Testing

2016 ◽  
Vol 2 (3_suppl) ◽  
pp. 14s-14s
Author(s):  
Benjamin A. Katchman ◽  
Joseph T. Smith ◽  
Jennifer Blain Christen ◽  
Karen S. Anderson
Keyword(s):  
Intellectual Property ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Manufacturing Technology ◽  
Analytical Sensitivity ◽  
State University ◽  
Arizona State University ◽  
New Approach ◽  
Display Technology

Abstract 62 One of the key roadblocks limiting the transition of high-sensitivity and high-specificity point-of-care technologies from the research laboratory to wide spread use is the availability of a low-cost-high-volume manufacturing technology. This work presents a new interdisciplinary approach combining low cost commercial display manufacturing technology with programmable high density protein microarray printing technology to fabricate disposable point-of-care immunosensors with clinical level sensitivity. Our approach is designed to leverage advances in commercial display technology to reduce pre-functionalized biosensor substrate costs to pennies per cm2, as well as to leverage the display industry’s ability to manufacture an immense number of low cost consumer electronic products annually. For this work, we demonstrate that our new approach can offer diagnostic sensitivity at or below 10 pg/mL, which approaches the lower limit of detection of typical clinical laboratory instrumentation. Our new approach is also designed to overcome the limited analytical sensitivity of existing POC devices (>100x improved sensitivity). It also contains new capability for multiplexed biomarker detection (>10 antigens) in a single low cost POC device through an innovative disposable and scalable architecture, based on flat panel display technology. Here, we demonstrate multiplexed detection of antibodies to the HPV16 proteins E2, E6, and E7, which are circulating biomarkers for cervical as well as head and neck cancers. This detection technology has 100 percent correlation to our current laboratory-based measurement instrumentation. AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST: Benjamin A. Katchman Patents, Royalties, Other Intellectual Property: Arizona State University Joseph T. Smith Patents, Royalties, Other Intellectual Property: Arizona State University Jennifer Blain Christen Patents, Royalties, Other Intellectual Property: Arizona State University Karen S. Anderson Stock or Other Ownership: Provista Diagnostics Consulting or Advisory Role: Provista Diagnostics Patents, Royalties, Other Intellectual Property: Arizona State University

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