scholarly journals Programmable Paper-Based Microfluidic Devices for Biomarker Detections

Micromachines ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 516 ◽  
Author(s):  
Veasna Soum ◽  
Sooyong Park ◽  
Albertus Ivan Brilian ◽  
Oh-Sun Kwon ◽  
Kwanwoo Shin
Keyword(s):  
Point Of Care ◽  
High Sensitivity ◽  
Microfluidic Devices ◽  
Portable Devices ◽  
Biomarker Detection ◽  
Fluid Delivery ◽  
Wide Range ◽  
Paper Based Microfluidics ◽  
Digital Microfluidic ◽  
Detection Of Biomarkers

Recent advanced paper-based microfluidic devices provide an alternative technology for the detection of biomarkers by using affordable and portable devices for point-of-care testing (POCT). Programmable paper-based microfluidic devices enable a wide range of biomarker detection with high sensitivity and automation for single- and multi-step assays because they provide better control for manipulating fluid samples. In this review, we examine the advances in programmable microfluidics, i.e., paper-based continuous-flow microfluidic (p-CMF) devices and paper-based digital microfluidic (p-DMF) devices, for biomarker detection. First, we discuss the methods used to fabricate these two types of paper-based microfluidic devices and the strategies for programming fluid delivery and for droplet manipulation. Next, we discuss the use of these programmable paper-based devices for the single- and multi-step detection of biomarkers. Finally, we present the current limitations of paper-based microfluidics for biomarker detection and the outlook for their development.

scholarly journals Immobilized Enzymes in Biosensor Applications

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 121 ◽  
Author(s):  
Hoang Hiep Nguyen ◽  
Sun Hyeok Lee ◽  
Ui Jin Lee ◽  
Cesar D. Fermin ◽  
Moonil Kim
Keyword(s):  
Point Of Care ◽  
Measurement Techniques ◽  
Diagnostic Testing ◽  
High Sensitivity ◽  
Immobilized Enzymes ◽  
Clinical Analysis ◽  
Safety Control ◽  
Wide Range ◽  
Piezoelectric Measurement ◽  
Innovative Techniques

Enzyme-based biosensing devices have been extensively developed over the last few decades, and have proven to be innovative techniques in the qualitative and quantitative analysis of a variety of target substrates over a wide range of applications. Distinct advantages that enzyme-based biosensors provide, such as high sensitivity and specificity, portability, cost-effectiveness, and the possibilities for miniaturization and point-of-care diagnostic testing make them more and more attractive for research focused on clinical analysis, food safety control, or disease monitoring purposes. Therefore, this review article investigates the operating principle of enzymatic biosensors utilizing electrochemical, optical, thermistor, and piezoelectric measurement techniques and their applications in the literature, as well as approaches in improving the use of enzymes for biosensors.

scholarly journals Colorimetric Sensing with Gold Nanoparticles on Electrowetting-Based Digital Microfluidics

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1423
Author(s):  
Zhen Gu ◽  
Jing-Jing Luo ◽  
Le-Wei Ding ◽  
Bing-Yong Yan ◽  
Jia-Le Zhou ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Low Cost ◽  
Digital Microfluidics ◽  
High Sensitivity ◽  
Bulk Solution ◽  
Label Free ◽  
Colorimetric Sensing ◽  
Wide Range ◽  
The Stability ◽  
Digital Microfluidic

Digital microfluidic (DMF) has been a unique tool for manipulating micro-droplets with high flexibility and accuracy. To extend the application of DMF for automatic and in-site detection, it is promising to introduce colorimetric sensing based on gold nanoparticles (AuNPs), which have advantages including high sensitivity, label-free, biocompatibility, and easy surface modification. However, there is still a lack of studies for investigating the movement and stability of AuNPs for in-site detection on the electrowetting-based digital microfluidics. Herein, to demonstrate the ability of DMF for colorimetric sensing with AuNPs, we investigated the electrowetting property of the AuNPs droplets on the hydrophobic interface of the DMF chip and examined the stability of the AuNPs on DMF as well as the influence of evaporation to the colorimetric sensing. As a result, we found that the electrowetting of AuNPs fits to a modified Young–Lippmann equation, which suggests that a higher voltage is required to actuate AuNPs droplets compared with actuating water droplets. Moreover, the stability of AuNPs was maintained during the processing of electrowetting. We also proved that the evaporation of droplets has a limited influence on the detections that last several minutes. Finally, a model experiment for the detection of Hg2+ was carried out with similar results to the detections in bulk solution. The proposed method can be further extended to a wide range of AuNPs-based detection for label-free, automatic, and low-cost detection of small molecules, biomarkers, and metal ions.

scholarly journals Advances in Mid-Infrared Spectroscopy-Based Sensing Techniques for Exhaled Breath Diagnostics

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2227 ◽  
Author(s):  
Ramya Selvaraj ◽  
Nilesh J. Vasa ◽  
S. M. Shiva Nagendra ◽  
Boris Mizaikoff
Keyword(s):  
Point Of Care ◽  
High Sensitivity ◽  
Special Focus ◽  
Exhaled Breath ◽  
Biomarker Detection ◽  
Mid Infrared ◽  
Optical Instruments ◽  
Single Breath ◽  
Volatile Organic ◽  
Recent Developments

Human exhaled breath consists of more than 3000 volatile organic compounds, many of which are relevant biomarkers for various diseases. Although gas chromatography has been the gold standard for volatile organic compound (VOC) detection in exhaled breath, recent developments in mid-infrared (MIR) laser spectroscopy have led to the promise of compact point-of-care (POC) optical instruments enabling even single breath diagnostics. In this review, we discuss the evolution of MIR sensing technologies with a special focus on photoacoustic spectroscopy, and its application in exhaled breath biomarker detection. While mid-infrared point-of-care instrumentation promises high sensitivity and inherent molecular selectivity, the lack of standardization of the various techniques has to be overcome for translating these techniques into more widespread real-time clinical use.

Reusable Surface Molecular Imprint Biosensors Aided by Naturally Occurring Surface Roughness Indices for Point-of-Care Diagnostics

MRS Advances ◽  
2019 ◽  
Vol 4 (22) ◽  
pp. 1299-1308 ◽  
Author(s):  
Yehoshua Auerbach ◽  
Rebecca Isseroff ◽  
Nicholas Clayton ◽  
Miguel Hulyalkar ◽  
Andrew Todt ◽  
...  
Keyword(s):  
Real Time ◽  
Molecular Imprinting ◽  
Point Of Care ◽  
High Sensitivity ◽  
Cost Effective ◽  
Stem Cell Differentiation ◽  
Diverse Range ◽  
Point Of Care Diagnostics ◽  
Molecular Imprint ◽  
Detection Of Biomarkers

ABSTRACTWe have shown that molecular imprinting (MI) technology can be used to produce sensitive, robust, cost-effective biosensing systems with a real-time electrochemical readout that can be utilized for point of care diagnostics. Real time detection of biomarkers is essential when rapid, critical decisions need to be made, such as in situations where public health is threatened. Our biosensor has high sensitivity compared to standard methods like ELISA, and results are obtained within minutes, using inexpensive, accessible potentiometric readout technology. These biosensors utilize surface molecular imprinting of a self-assembling monolayer of hydroxy-terminated alkanethiol chains which form a crystalline ‘lock-and-key’ structure around a target analyte, allowing the sensors to detect and differentiate between bio-macromolecules of similar size and shape with high selectivity and sensitivity. The sensors are extremely versatile and able to detect a diverse range of molecules of varied chemical composition and structure. To fully exploit the sensors’ advantages, especially in remote, economically disadvantaged areas, it is important to quantify their durability and reusability. Biosensor chips were created to test the viability of hemoglobin detection and to evaluate the potential for sensor reusability when washed after detection testing. The successful readsorption of hemoglobin even after washing, accompanied by cyclic voltammetry data indicating the preservation of the SAM, indicate that these biosensors are reusable, significantly augmenting the device’s value. Potential applications include the analysis of complex chemical and biological processes such as stem cell differentiation and on-the-spot detection of diseases such as Zika.

scholarly journals Modifying Wicking Speeds in Paper-Based Microfluidic Devices by Laser-Etching

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 773
Author(s):  
Brent Kalish ◽  
Mick Kyle Tan ◽  
Hideaki Tsutsui
Keyword(s):  
Flow Control ◽  
Point Of Care ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Diagnostic Tools ◽  
Laser Etching ◽  
Simple Process ◽  
Channel Geometry ◽  
Fluid Delivery ◽  
Reaction Zones

Paper-based microfluidic devices are an attractive platform for developing low-cost, point-of-care diagnostic tools. As paper-based devices’ detection chemistries become more complex, more complicated devices are required, often entailing the sequential delivery of different liquids or reagents to reaction zones. Most research into flow control has been focused on introducing delays. However, delaying the flow can be problematic due to increased evaporation leading to sample loss. We report the use of a CO2 laser to uniformly etch the surface of the paper to modify wicking speeds in paper-based microfluidic devices. This technique can produce both wicking speed increases of up to 1.1× faster and decreases of up to 0.9× slower. Wicking speeds can be further enhanced by etching both sides of the paper, resulting in wicking 1.3× faster than unetched channels. Channels with lengthwise laser-etched grooves were also compared to uniformly etched channels, with the most heavily grooved channels wicking 1.9× faster than the fastest double-sided etched channels. Furthermore, sealing both sides of the channel in packing tape results in the most heavily etched channels, single-sided, double-sided, and grooved, wicking over 13× faster than unetched channels. By selectively etching individual channels, different combinations of sequential fluid delivery can be obtained without altering any channel geometry. Laser etching is a simple process that can be integrated into the patterning of the device and requires no additional materials or chemicals, enabling greater flow control for paper-based microfluidic devices.

scholarly journals Fabrication, Flow Control, and Applications of Microfluidic Paper-Based Analytical Devices

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2869 ◽  
Author(s):  
Lim ◽  
Jafry ◽  
Lee
Keyword(s):  
Fluid Flow ◽  
High Performance ◽  
Point Of Care ◽  
High Sensitivity ◽  
Theoretical Background ◽  
Detection Techniques ◽  
Advantages And Disadvantages ◽  
Sensitivity And Selectivity ◽  
Paper Based Microfluidics ◽  
Flow Manipulation

Paper-based microfluidic devices have advanced significantly in recent years as they are affordable, automated with capillary action, portable, and biodegradable diagnostic platforms for a variety of health, environmental, and food quality applications. In terms of commercialization, however, paper-based microfluidics still have to overcome significant challenges to become an authentic point-of-care testing format with the advanced capabilities of analyte purification, multiplex analysis, quantification, and detection with high sensitivity and selectivity. Moreover, fluid flow manipulation for multistep integration, which involves valving and flow velocity control, is also a critical parameter to achieve high-performance devices. Considering these limitations, the aim of this review is to (i) comprehensively analyze the fabrication techniques of microfluidic paper-based analytical devices, (ii) provide a theoretical background and various methods for fluid flow manipulation, and iii) highlight the recent detection techniques developed for various applications, including their advantages and disadvantages.

scholarly journals Point-of-care ultrasound in primary care: a systematic review of generalist performed point-of-care ultrasound in unselected populations

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Bjarte Sorensen ◽  
Steinar Hunskaar
Keyword(s):  
Systematic Review ◽  
Emergency Medicine ◽  
General Practitioners ◽  
Clinical Studies ◽  
Point Of Care ◽  
High Sensitivity ◽  
High Specificity ◽  
Point Of Care Ultrasound ◽  
Organ Systems ◽  
Wide Range

Abstract Background Both the interest and actual extent of use of point-of-care ultrasound, PoCUS, among general practitioners or family physicians are increasing and training is also increasingly implemented in residency programs. However, the amount of research within the field is still rather limited compared to what is seen within other specialties in which it has become more established, such as in the specialty of emergency medicine. An assumption is made that what is relevant for emergency medicine physicians and their populations is also relevant to the general practitioner, as both groups are generalists working in unselected populations. This systematic review aims to examine the extent of use and to identify clinical studies on the use of PoCUS by either general practitioners or emergency physicians on indications that are relevant for the former, both in their daily practice and in out-of-hours services. Methods Systematic searches were done in PubMed/MEDLINE using terms related to general practice, emergency medicine, and ultrasound. Results On the extent of use, we identified 19 articles, as well as 26 meta-analyses and 168 primary studies on the clinical use of PoCUS. We found variable, but generally low, use among general practitioners, while it seems to be thoroughly established in emergency medicine in North America, and increasingly also in the rest of the world. In terms of clinical studies, most were on diagnostic accuracy, and most organ systems were studied; the heart, lungs/thorax, vessels, abdominal and pelvic organs, obstetric ultrasound, the eye, soft tissue, and the musculoskeletal system. The studies found in general either high sensitivity or high specificity for the particular test studied, and in some cases high total accuracy and superiority to other established diagnostic imaging modalities. PoCUS also showed faster time to diagnosis and change in management in some studies. Conclusion Our review shows that generalists can, given a certain level of pre-test probability, safely use PoCUS in a wide range of clinical settings to aid diagnosis and better the care of their patients.

scholarly journals Chronometric Quantitation of Analytes in Paper-Based Microfluidic Devices (MicroPADs) via Enzymatic Degradation of a Metastable Biomatrix

Inventions ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 48
Author(s):  
Aditya R. Jangid ◽  
E. Brandon Strong ◽  
Emiliano Escamilla ◽  
Brittany A. Lore ◽  
Nicholas J. Tod ◽  
...  
Keyword(s):  
Enzymatic Degradation ◽  
Point Of Care ◽  
Patent Application ◽  
Microfluidic Devices ◽  
World Health ◽  
The World ◽  
Lateral Flow Assays ◽  
Biomarker Quantitation ◽  
Health Organization ◽  
Detection Of Biomarkers

The following article summarizes United States Patent Application No. US20180052155A1, titled ‘Assay Devices and Methods’ (filed 16 August 2016, published 22 February 2018). While lateral flow assays (LFAs) have revolutionized point-of-care diagnostics by enabling accurate, inexpensive, and rapid detection of biomarkers, they typically do not provide quantitative results. Hence, there is a significant need for quantitative assays at the point of care. This patent summary describes a novel method of chronometric biomarker quantitation via enzymatic degradation of a metastable gelatin-based biomatrix, principally suited for use in paper-based microfluidic devices (microPADs). This new quantitation mechanism was designed to meet the ASSURED criteria for point-of-care diagnostic devices laid forth by the World Health Organization and may ultimately provide increased access to healthcare, at a significantly reduced cost, around the world.

scholarly journals Electrochemiluminescence Biosensors Using Screen-Printed Electrodes

Biosensors ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 118
Author(s):  
Emiliano Martínez-Periñán ◽  
Cristina Gutiérrez-Sánchez ◽  
Tania García-Mendiola ◽  
Encarnación Lorenzo
Keyword(s):  
Dna Analysis ◽  
Dynamic Range ◽  
Chemical Properties ◽  
High Sensitivity ◽  
Portable Devices ◽  
Research Fields ◽  
Sensing Applications ◽  
Screen Printed Electrodes ◽  
Wide Range ◽  
Screen Printed

Electrogenerated chemiluminescence (also called electrochemiluminescence (ECL)) has become a great focus of attention in different fields of analysis, mainly as a consequence of the potential remarkably high sensitivity and wide dynamic range. In the particular case of sensing applications, ECL biosensor unites the benefits of the high selectivity of biological recognition elements and the high sensitivity of ECL analysis methods. Hence, it is a powerful analytical device for sensitive detection of different analytes of interest in medical prognosis and diagnosis, food control and environment. These wide range of applications are increased by the introduction of screen-printed electrodes (SPEs). Disposable SPE-based biosensors cover the need to perform in-situ measurements with portable devices quickly and accurately. In this review, we sum up the latest biosensing applications and current progress on ECL bioanalysis combined with disposable SPEs in the field of bio affinity ECL sensors including immunosensors, DNA analysis and catalytic ECL sensors. Furthermore, the integration of nanomaterials with particular physical and chemical properties in the ECL biosensing systems has improved tremendously their sensitivity and overall performance, being one of the most appropriates research fields for the development of highly sensitive ECL biosensor devices.

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