scholarly journals Acoustofluidic Micromixing Enabled Hybrid Integrated Colorimetric Sensing, for Rapid Point-of-Care Measurement of Salivary Potassium

Biosensors ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 73 ◽  
Author(s):  
Vikram Surendran ◽  
Thomas Chiulli ◽  
Swetha Manoharan ◽  
Stephen Knisley ◽  
Muthukumaran Packirisamy ◽  
...  
Keyword(s):  
Color Change ◽  
Point Of Care ◽  
Sample Volume ◽  
Point Of Care Testing ◽  
Colorimetric Sensing ◽  
In Situ Tests ◽  
Detection Scheme ◽  
Chip Technology ◽  
Whole Saliva ◽  
Microfluidic Biosensor

The integration of microfluidics with advanced biosensor technologies offers tremendous advantages such as smaller sample volume requirement and precise handling of samples and reagents, for developing affordable point-of-care testing methodologies that could be used in hospitals for monitoring patients. However, the success and popularity of point-of-care diagnosis lies with the generation of instantaneous and reliable results through in situ tests conducted in a painless, non-invasive manner. This work presents the development of a simple, hybrid integrated optical microfluidic biosensor for rapid detection of analytes in test samples. The proposed biosensor works on the principle of colorimetric optical absorption, wherein samples mixed with suitable chromogenic substrates induce a color change dependent upon the analyte concentration that could then be detected by the absorbance of light in its path length. This optical detection scheme has been hybrid integrated with an acoustofluidic micromixing unit to enable uniform mixing of fluids within the device. As a proof-of-concept, we have demonstrated the real-time application of our biosensor format for the detection of potassium in whole saliva samples. The results show that our lab-on-a-chip technology could provide a useful strategy in biomedical diagnoses for rapid analyte detection towards clinical point-of-care testing applications.

Paper-based selective and quantitative detection of uric acid using citrate-capped Pt nanoparticles (PtNPs) as a colorimetric sensing probe through a simple and remote-based device

2019 ◽  
Vol 43 (20) ◽  
pp. 7636-7645 ◽  
Author(s):  
Muhsin Ali ◽  
Muhammad Asad Ullah Khalid ◽  
Imran Shah ◽  
Soo Wan Kim ◽  
Young Su Kim ◽  
...  
Keyword(s):  
Uric Acid ◽  
Point Of Care ◽  
Pt Nanoparticles ◽  
Quantitative Detection ◽  
Point Of Care Testing ◽  
Colorimetric Sensing

A colorimetric portable setup was developed for remote UA measurements using a smartphone-based application to demonstrate its use in point-of-care testing.

scholarly journals Microfluidic Paper-Based Analytical Devices for Colorimetric Detection of Lactoferrin

2019 ◽  
Vol 25 (1) ◽  
pp. 47-57 ◽  
Author(s):  
Hiroko Kudo ◽  
Kento Maejima ◽  
Yuki Hiruta ◽  
Daniel Citterio
Keyword(s):  
Color Change ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Color Intensity ◽  
Colorimetric Sensing ◽  
Detection Mechanism ◽  
Fiber Network ◽  
Water Dispersible ◽  
Physical Entrapment

Lactoferrin is an abundant glycoprotein in human body fluids and is known as a biomarker for various diseases. Therefore, point-of-care testing (POCT) for lactoferrin is of interest. Microfluidic paper-based analytical devices (µPADs) have gained a lot of attention as next-generation POCT device candidates, due to their inexpensiveness, operational simplicity, and being safely disposable. This work presents a colorimetric sensing approach for quantitative lactoferrin analysis. The detection mechanism takes advantage of the high affinity of lactoferrin to ferric ions (Fe3+). Lactoferrin is able to displace an indicator from a colorimetric 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP)-Fe3+ complex, resulting in a color change. A 5-Br-PADAP-Fe3+ complex was encapsulated into water-dispersible poly(styrene- block-vinylpyrrolidone) particles, whose physical entrapment in the cellulosic fiber network results in the immobilization of the complex to the paper matrix. The complex-encapsulating particles showed a color change response in accordance with lactoferrin concentration. Both color intensity-based paper well plates and distance readout-based µPADs are demonstrated. Color intensity-based devices allowed quantitative analysis of lactoferrin concentrations with a limit of detection of 110 µg/mL, using a smartphone and a color readout app. On the other hand, distance readout-based µPADs showed changes of the length of colored sections in accordance with lactoferrin concentration. In summary, we successfully developed both colorimetric intensity-based paper wells and distance-based µPADs for lactoferrin detection. This work demonstrates a user-friendly colorimetric analysis platform for lactoferrin without requiring lab equipment and expensive antibodies.

Pen-on-paper strategy for point-of-care testing: Rapid prototyping of fully written microfluidic biosensor

2017 ◽  
Vol 98 ◽  
pp. 478-485 ◽  
Author(s):  
Zedong Li ◽  
Fei Li ◽  
Yue Xing ◽  
Zhi Liu ◽  
Minli You ◽  
...  
Keyword(s):  
Rapid Prototyping ◽  
Point Of Care ◽  
Point Of Care Testing ◽  
Microfluidic Biosensor

Use of quality indicators to compare point-of-care testing errors in a neonatal unit and errors in a STAT central laboratory

2015 ◽  
Vol 53 (2) ◽  
Author(s):  
Miguel Cantero ◽  
Maximino Redondo ◽  
Eva Martín ◽  
Gonzalo Callejón ◽  
María Luisa Hortas
Keyword(s):  
Quality Indicators ◽  
Point Of Care ◽  
Sample Volume ◽  
Error Rates ◽  
Internal Quality ◽  
Central Laboratory ◽  
Point Of Care Testing ◽  
Patient Identification ◽  
Preanalytical Phase ◽  
Analytical Phase

AbstractPoint-of-care testing (POCT), like other laboratory tests, can be affected by errors throughout the total testing process. To evaluate quality error rates, the use of quality indicators (QIs) is recommended; however, little information is available on the quality error rate associated with POCT. The objective of this study was to investigate quality error rates related to POCT and compare them with central laboratory (CL) testing.We studied standardized QIs for POCT in comparison to CL testing. We compared error rates related to requests, collection, and handling of samples and results from external quality assessment program (EQAP) and internal quality control (IQC).The highest difference between POCT and CL testing was observed for QI related to patient identification, 45.3% vs. 0.02% (p<0.001). Regarding specimen collection and handling, the QI related to samples without results was also higher in POCT than in CL testing, 15.8% vs. 3.3% (p<0.001). For the QI related to insufficient sample volume, we obtained 2.9% vs. 0.9% (p=0.27). Unlike QIs for the preanalytical phase, QIs for the analytical phase had better results in POCT than CL testing. We obtained 8.3% vs. 16.6% (p=0.13) for QI related to unacceptable results in EQAP and 0.8% vs. 22.5% (p<0.001) for QI related to unacceptable results in IQC.Our results show that the preanalytical phase remains the main problem in POCT like in CL testing and that monitoring of quality indicators is a very valuable tool in reducing errors in POCT.

scholarly journals Nanoplasmonic Strip Test for Salivary Glucose Monitoring

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 105
Author(s):  
Helena Torné-Morató ◽  
Paolo Donati ◽  
Pier Paolo Pompa
Keyword(s):  
Recent Progress ◽  
Color Change ◽  
Point Of Care ◽  
Glucose Monitoring ◽  
Quantitative Detection ◽  
Self Monitoring ◽  
Fully Integrated ◽  
Red Color ◽  
Whole Saliva ◽  
Strip Test

Nowadays, there is an increasing interest in Point-of-care (POC) devices for the noninvasive glucose assessment. Despite the recent progress in glucose self-monitoring, commercially available devices still use invasive samples such as blood or interstitial fluids, and they are not equipment-free and affordable for the whole population. Here, we report a fully integrated strip test for the semi-quantitative detection of glucose in whole saliva. The colorimetric mechanism consists of an enzyme-mediated reshaping of multibranched gold nanoparticles (MGNPs) into nanospheres with an associated plasmonic shift and consequent blue-to-red color change, clearly detectable in less than 10 min.

Portable Simultaneous Multiple Analyte Whole-Blood Analyzer for Point-of-Care Testing

1992 ◽  
Vol 38 (9) ◽  
pp. 1665-1670 ◽  
Author(s):  
C T Schembri ◽  
V Ostoich ◽  
P J Lingane ◽  
T L Burd ◽  
S N Buhl
Keyword(s):  
Whole Blood ◽  
Clinical Chemistry ◽  
Point Of Care ◽  
Sample Volume ◽  
Calibration Data ◽  
Portable Instrument ◽  
Point Of Care Testing ◽  
Bar Code ◽  
Single Use ◽  
Multiple Analytes

Abstract We describe a portable clinical chemistry analyzer for point-of-care measurements of multiple analytes in less than 10 min from approximately 40 microL of whole blood (fingerstick or venous). Whole blood is applied directly to a 7.9-cm-diameter, single-use plastic rotor containing liquid diluent and greater than or equal to 4-12 tests in the form of 1- to 2-mm-diameter dry reagent beads. The reagent/rotor is immediately placed in a portable instrument along with a ticket/label results card. As the instrument spins the rotor, capillary and rotational forces process the blood into diluted plasma, distribute the patient's diluted sample to cuvettes containing the reagent beads, and mix the diluted sample with the reagents. The instrument monitors the chemical reactions optically at nine wavelengths; sample volume and temperature are also measured optically. The calibration data for each reagent are read from a bar code on the periphery of each rotor. The instrument processes all the measurements to calculate, store, print, and communicate the results. Each reagent/rotor contains an enzymatic control that must be within a defined range before the results from that analysis are reported.

Development of a Gold Nanoparticle-Based Colorimetric Sensor for Water for Injection At-Line Impurity Testing

2020 ◽  
pp. 247263032097818
Author(s):  
Saskia Reichelt ◽  
Elke Boschke ◽  
Olena Reinhardt ◽  
Thomas Walther ◽  
Felix Lenk
Keyword(s):  
Septic Shock ◽  
Point Of Care ◽  
Rapid Test ◽  
Sample Volume ◽  
Gram Negative Bacteria ◽  
Point Of Care Testing ◽  
Limulus Amebocyte Lysate ◽  
Regulatory Requirements ◽  
Gram Negative ◽  
Line Process

The best-known rapid test using gold nanoparticles (AuNPs) is the human chorionic gonadotropin pregnancy test. AuNPs are a powerful tool in point-of-care testing because of their flexibility, modifiability, and visibility. Here, we report a method to detect impurities for at-line process control in water-for-injection (WFI) manufacturing through the example of endotoxins. If a distinct concentration of these amphipathic molecules, originated from gram-negative bacteria, enters the human body, it will result in septic shock, followed by organ failure and possibly death. Every fluid given parenterally is subject to strict regulatory requirements and therefore endotoxin testing. Through use of traditional methods like the limulus amebocyte lysate (LAL) test, it takes more than 2 h to complete. With the presented method, one-fifth of the sample volume is sufficient compared with the LAL test. Once the assay components have been mixed, the result can be interpreted visually within 2 min without the use of further instruments.

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