scholarly journals Deep Learning-Enabled Point-of-Care Sensing Using Multiplexed Paper-Based Sensors

2019 ◽  
Author(s):  
Zachary Ballard ◽  
Hyou-Arm Joung ◽  
Artem Goncharov ◽  
Jesse Liang ◽  
Karina Nugroho ◽  
...  

ABSTRACTWe present a deep learning-based framework to design and quantify point-of-care sensors. As its proof-of-concept and use-case, we demonstrated a low-cost and rapid paper-based vertical flow assay (VFA) for high sensitivity C-Reactive Protein (hsCRP) testing, a common medical test used for quantifying the degree of inflammation in patients at risk of cardio-vascular disease (CVD). A machine learning-based sensor design framework was developed for two key tasks: (1) to determine an optimal configuration of immunoreaction spots and conditions, spatially-multiplexed on a paper-based sensing membrane, and (2) to accurately infer the target analyte concentration based on the signals of the optimal VFA configuration. Using a custom-designed mobile-phone based VFA reader, a clinical study was performed with 85 human serum samples to characterize the quantification accuracy around the clinically defined cutoffs for CVD risk stratification. Results from blindly-tested VFAs indicate a competitive coefficient of variation of 11.2% with a linearity of R2 = 0.95; in addition to the success in the high-sensitivity CRP range (i.e., 0-10 mg/L), our results further demonstrate a mitigation of the hook-effect at higher CRP concentrations due to the incorporation of antigen capture spots within the multiplexed sensing membrane of the VFA. This paper-based computational VFA that is powered by deep learning could expand access to CVD health screening, and the presented machine learning-enabled sensing framework can be broadly used to design cost-effective and mobile sensors for various point-of-care diagnostics applications.

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1192
Author(s):  
Hisham S. M. Abd-Rabboh ◽  
Abd El-Galil E. Amr ◽  
Abdulrahman A. Almehizia ◽  
Ayman H. Kamel

In recent times, the application of the use of ion-selective electrodes has expanded in the field of pharmaceutical analyses due to their distinction from other sensors in their high selectivity and low cost of measurement, in addition to their high measurement sensitivity. Cost-effective, reliable, and robust all-solid-state potentiometric selective electrodes were designed, characterized, and successfully used for pholcodine determination. The design of the sensor device was based on the use of a screen-printed electrode modified with multiwalled carbon nanotubes (MWCNTs) as a solid-contact transducer. Tailored pholcodine (PHO) molecularly imprinted polymers (MIPs) were prepared, characterized, and used as sensory receptors in the presented potentiometric sensing devices. The sensors exhibited a sensitivity of 31.6 ± 0.5 mV/decade (n = 5, R2 = 0.9980) over the linear range of 5.5 × 10−6 M with a detection limit of 2.5 × 10−7 M. Real serum samples in addition to pharmaceutical formulations containing PHO were analyzed, and the results were compared with those obtained by the conventional standard liquid chromatographic approach. The presented analytical device showed an outstanding efficiency for fast, direct, and low-cost assessment of pholcodine levels in different matrices.


Author(s):  
Antonia Perju ◽  
Nongnoot Wongkaew

AbstractLateral flow assays (LFAs) are the best-performing and best-known point-of-care tests worldwide. Over the last decade, they have experienced an increasing interest by researchers towards improving their analytical performance while maintaining their robust assay platform. Commercially, visual and optical detection strategies dominate, but it is especially the research on integrating electrochemical (EC) approaches that may have a chance to significantly improve an LFA’s performance that is needed in order to detect analytes reliably at lower concentrations than currently possible. In fact, EC-LFAs offer advantages in terms of quantitative determination, low-cost, high sensitivity, and even simple, label-free strategies. Here, the various configurations of EC-LFAs published are summarized and critically evaluated. In short, most of them rely on applying conventional transducers, e.g., screen-printed electrode, to ensure reliability of the assay, and additional advances are afforded by the beneficial features of nanomaterials. It is predicted that these will be further implemented in EC-LFAs as high-performance transducers. Considering the low cost of point-of-care devices, it becomes even more important to also identify strategies that efficiently integrate nanomaterials into EC-LFAs in a high-throughput manner while maintaining their favorable analytical performance.


Author(s):  
Pratyush Kaware

In this paper a cost-effective sensor has been implemented to read finger bend signals, by attaching the sensor to a finger, so as to classify them based on the degree of bent as well as the joint about which the finger was being bent. This was done by testing with various machine learning algorithms to get the most accurate and consistent classifier. Finally, we found that Support Vector Machine was the best algorithm suited to classify our data, using we were able predict live state of a finger, i.e., the degree of bent and the joints involved. The live voltage values from the sensor were transmitted using a NodeMCU micro-controller which were converted to digital and uploaded on a database for analysis.


Author(s):  
Zhijia Peng ◽  
Xiaogang Lin ◽  
Weiqi Nian ◽  
Xiaodong Zheng ◽  
Jayne Wu

Early diagnosis and treatment have always been highly desired in the fight against cancer, and detection of circulating tumor DNA (ctDNA) has recently been touted as highly promising for early cancer screening. Consequently, the detection of ctDNA in liquid biopsy gains much attention in the field of tumor diagnosis and treatment, which has also attracted research interest from the industry. However, traditional gene detection technology is difficult to achieve low cost, real-time and portable measurement of ctDNA. Electroanalytical biosensors have many unique advantages such as high sensitivity, high specificity, low cost and good portability. Therefore, this review aims to discuss the latest development of biosensors for minimal-invasive, rapid, and real-time ctDNA detection. Various ctDNA sensors are reviewed with respect to their choices of receptor probes, detection strategies and figures of merit. Aiming at the portable, real-time and non-destructive characteristics of biosensors, we analyze their development in the Internet of Things, point-of-care testing, big data and big health.


2021 ◽  
Vol 5 ◽  
pp. 239920262110550
Author(s):  
Joško Osredkar ◽  
Katja Krivic ◽  
Teja Fabjan ◽  
Kristina Kumer ◽  
Jure Tršan ◽  
...  

Aim: Although the levels of cardiac troponin I (cTnI) have proved to be a useful diagnostic biomarker of acute myocardial infarction, there are a wide variety of point-of-care (POC) analysers, which provide measurements of cTnI. The aim of this study was to compare the results obtained by the ADVIA Centaur ultra-assay cTnI assay (us-cTnI), ADVIA Centaur high-sensitive cTnI assay (hs-cTnI) and a POC high-sensitivity assay using PATHFAST. We also aimed to explore total turnaround time (TAT) for laboratory results using the POC PATHFAST analyser. Methods: Samples from 161 patients were taken. Of these samples, 129 were tested with all three assays (us-cTnI, hs-cTnI and PATHFAST), and 32 samples were tested on PATHFAST for the comparison of whole blood, serum and plasma. Results: Comparison of the POC testing methods in this study demonstrated that there are strong linear relationships between all three cTnI assays (us-cTnI, hs-cTnI and POC on PATHFAST). Furthermore, we also show there are strong linear relationships between the two high-sensitive cTnI assays (hs-cTnI and PATHFAST) for blood serum samples, as determined by Passing–Bablok regression analyses. In our comparison of our new data with our older study, the TAT went down. Conclusion: The timeliness of laboratory results is, in addition to accuracy and precision, one of the key indicators of laboratory performance, and at the same time has a significant impact on the course of the patient’s condition. It is therefore important that the laboratory strives to meet the expectations of clinicians regarding the time from the order to the result of the analysis.


Cataract is a degenerative condition that, according to estimations, will rise globally. Even though there are various proposals about its diagnosis, there are remaining problems to be solved. This paper aims to identify the current situation of the recent investigations on cataract diagnosis using a framework to conduct the literature review with the intention of answering the following research questions: RQ1) Which are the existing methods for cataract diagnosis? RQ2) Which are the features considered for the diagnosis of cataracts? RQ3) Which is the existing classification when diagnosing cataracts? RQ4) And Which obstacles arise when diagnosing cataracts? Additionally, a cross-analysis of the results was made. The results showed that new research is required in: (1) the classification of “congenital cataract” and, (2) portable solutions, which are necessary to make cataract diagnoses easily and at a low cost.


Biosensors ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 88 ◽  
Author(s):  
Nan Li ◽  
Ari M. Chow ◽  
Hashwin V. S. Ganesh ◽  
Melanie Ratnam ◽  
Ian R. Brown ◽  
...  

Altered growth hormone (GH) levels represent a major global health challenge that would benefit from advances in screening methods that are rapid and low cost. Here, we present a miniaturized immunosensor using disposable screen-printed carbon electrodes (SPCEs) for the detection of GH with high sensitivity. The diazonium-based linker layer was electrochemically deposited onto SPCE surfaces, and subsequently activated using covalent agents to immobilize monoclonal anti-GH antibodies as the sensing layer. The surface modifications were monitored using contact angle measurements and X-ray photoelectron spectroscopy (XPS). The dissociation constant, Kd, of the anti-GH antibodies was also determined as 1.44 (±0.15) using surface plasmon resonance (SPR). The immunosensor was able to detect GH in the picomolar range using a 20 µL sample volume in connection with electrochemical impedance spectroscopy (EIS). The selectivity of the SPCE-based immunosensors was also challenged with whole blood and serum samples collected at various development stages of rats, demonstrating the potential applicability for detection in biological samples. Our results demonstrated that SPCEs provided the development of low-cost and single-use electrochemical immunosensors in comparison with glassy carbon electrode (GCE)-based ones.


The Analyst ◽  
2016 ◽  
Vol 141 (12) ◽  
pp. 3898-3903 ◽  
Author(s):  
Maowei Dou ◽  
Juan Lopez ◽  
Misael Rios ◽  
Oscar Garcia ◽  
Chuan Xiao ◽  
...  

A low-cost b̲a̲ttery-powered s̲pectrophotometric s̲ystem (BASS) was developed for high-sensitivity point-of-care analysis in low-resource settings on a microfluidic chip without relying on external power supplies.


2011 ◽  
Vol 89 (1) ◽  
pp. 77-82 ◽  
Author(s):  
Stacey D. Haskins ◽  
Christina M. Harrison ◽  
David G. Kelly ◽  
Ron D. Weir

The present study considers simple and cost-effective modifications to commercial pressurised solvent extraction cells to extract polychlorinated biphenyls (PCBs) from avian blood and serum. Blood and serum samples of mass 0.2 g were examined. Such masses are consistent with those which may be obtained from many avian species without sacrificing individuals or compromising breeding and (or) migratory success. Extraction vessels are modified by the use of Teflon inserts, which are readily fabricated at low cost. These inserts reduce internal cell volume and surface area. Thus, background contamination is reduced whilst extraction and rinse solvent is used more effectively to afford a small extract volume. Packing of the cell void with sodium sulfate and florisil achieves in situ sample dehydration and lipid removal. When combined with extraction concentration and large volume injection gas chromatography – ion-trap mass spectrometry (LVI-GC–ITMS), the extraction method is capable of polychlorinated biphenyl analysis without post-extraction clean-up. Validation was accomplished using commercial chicken whole blood and serum, and PCB congeners 28, 77, 105, 126, 153, 167, 170, 180, 183, and 194. Surrogate corrected recoveries in the range of 75% to120% for whole blood and 80% to115% for serum were obtained. Detection limits were in the range of 0.01 to 0.22 ng g–1 for whole blood and 0.03 to 0.45 ng g–1 for serum. The relative standard deviations for all congeners investigated were better than 15%.


2021 ◽  
Author(s):  
Pattamaporn Kittayapong ◽  
Parinda Thayanukul ◽  
Benchaporn Lertanantawong ◽  
Worachart Sirawaraporn ◽  
Surat Charasmongkolcharoen ◽  
...  

Background Wolbachia is an endosymbiont bacterium generally found in about 40% of insects, including mosquitoes, but it is absent in Aedes aegypti which is an important vector of several arboviral diseasesdengue, chikungunya, Zika, and yellow fever. The evidence that Wolbachia trans-infected Ae. aegypti mosquitoes lost their vectorial competence and became less capable of transmitting arboviruses to human hosts highlights the potential of using Wolbachia - based approaches for prevention and control of arboviral diseases. Recently, release of Wolbachia trans-infected Ae. aegypti has been deployed widely in many countries for the control of mosquito-borne viral diseases. Field surveillance and monitoring of Wolbachia presence in released mosquitoes is important for the success of these control programs. So far, a number of studies have reported the development of loop mediated isothermal amplification (LAMP) assays to detect Wolbachia in mosquitoes, but the methods still have some specificity issues. Methodology/Principal Findings We describe here the development of a LAMP combined with the DNA strand displacement-based electrochemical sensor (BIOSENSOR) method to detect wAlbB Wolbachia in trans-infected Ae . aegypti . Our developed LAMP primers were more specific to wAlbB detection than those of the previous published ones if  the assays were conducted with low-cost and non-specific detecting dyes. The detection capacity of our LAMP technique was 3.8 nM and the detection limit reduced to 2.16 fM when combined with the BIOSENSOR. Our study demonstrates that the BIOSENSOR can also be applied as a stand-alone method for detecting Wolbachia ; and it showed high sensitivity when used with the crude DNA extracts of macerated mosquito samples without DNA purification. Conclusions/Significance Our results suggest that both LAMP and BIOSENSOR, either used in combination or stand-alone, are robust and sensitive. The methods have good potential for routine detection of Wolbachia in mosquitoes during field surveillance and monitoring of Wolbachia -based release programs, especially in countries with limited resources.


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