scholarly journals Portable device for the detection of colorimetric assays

2017 ◽  
Vol 4 (11) ◽  
pp. 171025 ◽  
Author(s):  
G. S. Luka ◽  
E. Nowak ◽  
J. Kawchuk ◽  
M. Hoorfar ◽  
H. Najjaran
Keyword(s):  
Standard Deviation ◽  
Point Of Care ◽  
Low Cost ◽  
Digital Camera ◽  
Portable Device ◽  
Ambient Light ◽  
Colorimetric Analysis ◽  
Ph Values ◽  
Resource Limited ◽  
Colorimetric Assays

In this work, a low-cost, portable device is developed to detect colorimetric assays for in-field and point-of-care (POC) analysis. The device can rapidly detect both pH values and nitrite concentrations of five different samples, simultaneously. After mixing samples with specific reagents, a high-resolution digital camera collects a picture of the sample, and a single-board computer processes the image in real time to identify the hue–saturation–value coordinates of the image. An internal light source reduces the effect of any ambient light so the device can accurately determine the corresponding pH values or nitrite concentrations. The device was purposefully designed to be low-cost, yet versatile, and the accuracy of the results have been compared to those from a conventional method. The results obtained for pH values have a mean standard deviation of 0.03 and a correlation coefficient R 2 of 0.998. The detection of nitrites is between concentrations of 0.4–1.6 mg l −1 , with a low detection limit of 0.2 mg l −1 , and has a mean standard deviation of 0.073 and an R 2 value of 0.999. The results represent great potential of the proposed portable device as an excellent analytical tool for POC colorimetric analysis and offer broad accessibility in resource-limited settings.

scholarly journals Validation of a point-of-care rapid diagnostic test for hepatitis C for use in resource-limited settings

2019 ◽  
Vol 11 (4) ◽  
pp. 314-315
Author(s):  
James S Leathers ◽  
Maria Belen Pisano ◽  
Viviana Re ◽  
Gertine van Oord ◽  
Amir Sultan ◽  
...  
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Rapid Diagnosis ◽  
Direct Acting Antivirals ◽  
Resource Limited Settings ◽  
Rapid Diagnosis Test ◽  
Resource Limited ◽  
Specificity And Sensitivity ◽  
Hcv Screening ◽  
Direct Acting

Abstract Background Treatment of HCV with direct-acting antivirals has enabled the discussion of HCV eradication worldwide. Envisioning this aim requires implementation of mass screening in resource-limited areas, usually constrained by testing costs. Methods We validated a low-cost, rapid diagnosis test (RDT) for HCV in three different continents in 141 individuals. Results The HCV RDT showed 100% specificity and sensitivity across different samples regardless of genotype or viral load (in samples with such information, 90%). Conclusions The HCV test validated in this study can allow for HCV screening in areas of need when properly used.

scholarly journals RAPPID: a platform of ratiometric bioluminescent sensors for homogeneous immunoassays

2020 ◽  
Author(s):  
Yan Ni ◽  
Bas J.H.M. Rosier ◽  
Eva A. van Aalen ◽  
Eva T.L. Hanckmann ◽  
Lieuwe Biewenga ◽  
...  
Keyword(s):  
Target Recognition ◽  
Point Of Care ◽  
Low Cost ◽  
Digital Camera ◽  
Spike Protein ◽  
Therapeutic Antibodies ◽  
Protein Biomarkers ◽  
External Calibration ◽  
Quantitative Measurements ◽  
Clinical Laboratories

AbstractHeterogeneous immunoassays such as ELISA have become indispensable in modern bioanalysis, yet translation into easy-to-use point-of-care assays is hindered by their dependence on external calibration and multiple washing and incubation steps. Here, we introduce RAPPID (Ratiometric Plug-and-Play Immunodiagnostics), a “mix-and-measure” homogeneous immunoassay platform that combines highly specific antibody-based detection with a ratiometric bioluminescent readout that can be detected using a basic digital camera. The concept entails analyte-induced complementation of split NanoLuc luciferase fragments, photoconjugated to an antibody sandwich pair via protein G adapters. We also introduce the use of a calibrator luciferase that provides a robust ratiometric signal, allowing direct in-sample calibration and quantitative measurements in complex media such as blood plasma. We developed RAPPID sensors that allow low-picomolar detection of several protein biomarkers, anti-drug antibodies, therapeutic antibodies, and both SARS-CoV-2 spike protein and anti-SARS-CoV-2 antibodies. RAPPID combines ratiometric bioluminescent detection with antibody-based target recognition into an easy-to-implement standardized workflow, and therefore represents an attractive, fast, and low-cost alternative to traditional immunoassays, both in an academic setting and in clinical laboratories for point-of-care applications.

scholarly journals Inkjet printing of paraffin on paper allows low-cost point-of-care diagnostics for pathogenic fungi

Cellulose ◽  
2020 ◽  
Vol 27 (13) ◽  
pp. 7691-7701 ◽  
Author(s):  
Anusha Prabhu ◽  
M. S. Giri Nandagopal ◽  
Prakash Peralam Yegneswaran ◽  
Hardik Ramesh Singhal ◽  
Naresh Kumar Mani
Keyword(s):  
Filter Paper ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Pathogenic Fungi ◽  
Sem Analysis ◽  
Qualitative Assessment ◽  
Resource Limited ◽  
Hydrophobic Barrier ◽  
Pore Blockage

Abstract We present a high resolution, ultra-frugal printing of paper microfluidic devices using in-house paraffin formulation on a simple filter paper. The patterns printed using an office inkjet printer formed a selective hydrophobic barrier of 4 ± 1 µm thickness with a hydrophilic channel width of 275 µm. These printed patterns effectively confine common aqueous solutions and solvents, which was verified by solvent compatibility studies. SEM analysis reveals that the solvent confinement is due to pore blockage in the filter paper. The fabricated paper-based device was validated for qualitative assessment of Candida albicans (pathogenic fungi) by using a combination of L-proline β-naphthylamide as the substrate and cinnamaldehyde as an indicator. Our studies reveal that the pathogenic fungi can be detected within 10 min with the limit of detection (LOD) of 0.86 × 106 cfu/mL. Owing to its simplicity, this facile method shows high potential and can be scaled up for developing robust paper-based devices for biomarker detection in resource-limited settings. Graphic abstract

3D Printing of Microfluidics for Point of Care Diagnosis

2017 ◽  
Author(s):  
John P. Sibbitt ◽  
Mei He
Keyword(s):  
3D Printing ◽  
Low Income ◽  
Point Of Care ◽  
Low Cost ◽  
High Sensitivity ◽  
Disease Diagnosis ◽  
Low Income Countries ◽  
3D Design ◽  
Resource Limited ◽  
Production Techniques

Microfluidic lab-on-a-chip (MLOC) technology is a promising approach for point-of-care (POC) diagnosis; low reagent consumption, high sensitivity and quick analysis time are the most prominent benefits. However, microfabrication of MLOCs utilizes specialized techniques and infrastructure, making conventional fabrication time consuming and difficult. While relatively inexpensive production techniques exist for POC diagnoses, such as replication of polymer-based (e.g., PDMS) microfluidic POC devices on lithographic molds, this approach has limitations including: further hydrophilic surface modifications of PDMS, inability to change lithographic mold Z dimensions, and slow prototyping. In contrast, stereo-lithographical (SLA) printing can integrate all of the necessary fabrication resources in one instrument, allowing highly versatile microfluidic devices to be made at low cost. In this paper, we report two microfabrication approaches of microfluidics utilizing (SLA) 3D printing technology: I) Direct SLA printing of channels and structures of a monolithic microfluidic POC device; II) Indirect fabrication, utilizing SLA 3D printed molds for PDMS based microfluidic device replication. Additionally, we discuss previous work providing a proof of concept of applications in POC diagnosis, using direct 3D printing fabrication (approach I). The robustness and simplicity of these protocols allow integrating 3D design and microfabrication with smartphone-based disease diagnosis as a stand-alone system, offering strong adaptability for establishing diagnostic capacity in resource-limited areas and low-income countries.

Low-Cost Optical Assays for Point-of-Care Diagnosis in Resource-Limited Settings

ACS Sensors ◽  
2021 ◽  
Author(s):  
Nan Jiang ◽  
Natha Dean Tansukawat ◽  
Laura Gonzalez-Macia ◽  
H. Ceren Ates ◽  
Can Dincer ◽  
...  
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Resource Limited Settings ◽  
Resource Limited

scholarly journals Smartphone-Based NFC Potentiostat for Wireless Electrochemical Sensing

2021 ◽  
Vol 11 (1) ◽  
pp. 392
Author(s):  
Karnpimon Krorakai ◽  
Supannika Klangphukhiew ◽  
Sirinan Kulchat ◽  
Rina Patramanon
Keyword(s):  
Cyclic Voltammetry ◽  
Point Of Care ◽  
Low Cost ◽  
Near Field ◽  
Electrochemical Techniques ◽  
Electrochemical Sensing ◽  
Voltage Range ◽  
Resource Limited ◽  
Electrochemical Devices ◽  
User Friendly

Most electrochemical sensing requires affordable, portable and easy-to-use electrochemical devices for use in point-of-care testing and resource-limited settings. This work presents the design and evaluates the analytical performance of a near-field communication (NFC) potentiostat, a flat card-sized electrochemical device containing a microchip for electrical analysis and an NFC antenna for smartphone connection. The NFC interface is a wireless connection between the microchip and smartphone to simplify measuring units and make the potentiostat into a passive operated device, running without a battery. The proposed potentiostat can perform the common electrochemical techniques including cyclic voltammetry and chronoamperometry with a current range and voltage range of ±20 µA and ±0.8 V. The performance of the NFC potentiostat is compared to a commercial benchtop potentiostat using ferricyanide as a standard solution. The results show that the NFC potentiostat is comparable to a commercial benchtop potentiostat for both cyclic voltammetry and chronoamperometry measurements. The application of the proposed potentiostat is demonstrated by measuring ascorbic acid concentration. As described, the NFC potentiostat, which is compatible with a smartphone, is low-cost, small in size and user-friendly. Thus, the device can be developed for on-site measurement to apply in various fields.

scholarly journals Microfluidic system for screening disease based on physical properties of blood

Bioimpacts ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 141-150
Author(s):  
Siddharth Singh Yadav ◽  
Basant Singh Sikarwar ◽  
Priya Ranjan ◽  
Rajiv Janardhanan
Keyword(s):  
Physical Properties ◽  
Large Scale ◽  
One Health ◽  
Point Of Care ◽  
Low Cost ◽  
Microfluidic System ◽  
Middle Income ◽  
Blood Samples ◽  
Resource Limited ◽  
Automated Classifier

Introduction: A key feature of the 'One Health' concept pertains to the design of novel point of care systems for largescale screening of health of the population residing in resource-limited areas of low- and middle-income countries with a view to obtaining data at a community level as a rationale to achieve better public health outcomes. The physical properties of blood are different for different samples. Our study involved the development of an innovative system architecture based upon the physical properties of blood using automated classifiers to enable large-scale screening of the health of the population living in resource-limited settings. Methods: The proposed system consisted of a simple, robust and low-cost sensor with capabilities to sense and measure even the minute changes in the physical properties of blood samples. In this system, the viscosity of blood was derived from a power-law model coupled with the Rabinowitsch-Mooney correction for non-Newtonian shear rates developed in a steady laminar Poiseuille flow. Surface tension was measured by solving the Young-Laplace equation for pendant drop shape hanging on a vertical needle. An anticipated outcome of this study would be the development of a novel automated classifier based upon the rheological attributes of blood. This automated classifier would have potential application in evaluating the health status of a population at regional and global levels. Results: The proposed system was used to measure the physical properties of various samples like normal, tuberculous and anemic blood samples. The results showed that the physical properties of these samples were different as compared to normal blood samples. The major advantage of this system was low-cost, as well as its simplicity and portability. Conclusion: In this work, we proposed making a case for the validation of a low-cost version of a microfluidic system capable of scanning large populations for a variety of diseases as per the WHO mandate of "One Health".

scholarly journals Nucleic acid amplification by a transparent graphene Visual-PCR chip and a disposable thermocycler

2019 ◽  
Author(s):  
Guozhi Zhu ◽  
Miao Qiao
Keyword(s):  
Nucleic Acids ◽  
Color Change ◽  
Point Of Care ◽  
Low Cost ◽  
Nucleic Acid Amplification ◽  
Driving Voltage ◽  
Conductive Films ◽  
Cooling Fan ◽  
Resource Limited ◽  
Polymerase Chain

ABSTRACTPolymerase chain reaction (PCR) is a method widely used to amplify trace amount of nucleic acids. It needs a process of thermocycling (repeated alternation of temperature). Traditional thermocycler relies on bulk size of metal block to achieve thermocycling, which results in high cost and the lack of portability. Here, a PCR chip made of graphene Transparent Conductive Films (TCFs) was employed. The thermocycling of the chip was fulfilled by a temperature programed microcontroller and a cooling fan under a low driving voltage (12V). A 35 cycles PCR was accomplished within 13 minutes using the chip and the thermocycler. The transparency of the graphene PCR chip enables the PCR reaction to be visually monitored by naked eye for a color change. The PCR chip and the thermocycler have a low cost at $2.5 and $6 respectively, and thus are feasible for Point-of-care testing (POCT) of nucleic acids in a disposable manner. The whole platform makes it possible to perform a low-cost testing of nucleic acids for varieties of purposes outside of laboratories or at resource limited locations.

scholarly journals Design of a Novel Low Cost Point of Care Tampon (POCkeT) Colposcope for Use in Resource Limited Settings

PLoS ONE ◽  
2015 ◽  
Vol 10 (9) ◽  
pp. e0135869 ◽  
Author(s):  
Christopher T. Lam ◽  
Marlee S. Krieger ◽  
Jennifer E. Gallagher ◽  
Betsy Asma ◽  
Lisa C. Muasher ◽  
...  
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Resource Limited Settings ◽  
Resource Limited
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