Smartphone dongle for simultaneous measurement of hemoglobin concentration and detection of HIV antibodies

Moving toward smart biomedical sensing

The development of novel biomedical sensors as highly promising devices/tools in early diagnosis and therapy monitoring of many diseases and disorders has recently witnessed unprecedented growth; more and faster than ever. Nonetheless, on the eve of Industry 5.0 and by learning from defects of current sensors in smart diagnostics of pandemics, there is still a long way to go to achieve the ideal biomedical sensors capable of meeting the growing needs and expectations for smart biomedical/diagnostic sensing through eHealth systems. Herein, an overview is provided to highlight the importance and necessity of an inevitable transition in the era of digital health/Healthcare 4.0 towards smart biomedical/diagnostic sensing and how to approach it via new digital technologies including Internet of Things (IoT), artificial intelligence, IoT gateways (smartphones, readers), etc. This review will bring together the different types of smartphone/reader-based biomedical sensors, which have been employing for a wide variety of optical/electrical/electrochemical biosensing applications and paving the way for future eHealth diagnostic devices by moving towards smart biomedical sensing. Here, alongside highlighting the characteristics/criteria that should be met by the developed sensors towards smart biomedical sensing, the challenging issues ahead are delineated along with a comprehensive outlook on this extremely necessary field.

Review of HIV Self Testing Technologies and Promising Approaches for the Next Generation

The ability to self-test for HIV is vital to preventing transmission, particularly when used in concert with HIV biomedical prevention modalities, such as pre-exposure prophylaxis (PrEP). In this paper, we review recent developments in HIV self-testing and self-sampling methods, and the potential future impact of novel materials and methods that emerged through efforts to develop more effective point-of-care (POC) SARS-CoV-2 diagnostics. We address the gaps in existing HIV self-testing technologies, where improvements in test sensitivity, sample-to-answer time, simplicity, and cost are needed to enhance diagnostic accuracy and widespread accessibility. We discuss potential paths toward the next generation of HIV self-testing through sample collection materials, biosensing assay techniques, and miniaturized instrumentation. We discuss the implications for other applications, such as self-monitoring of HIV viral load and other infectious diseases.

Portable general microfluidic device with complex electric field regulation functions for electrokinetic experiments

Electrokinetic sample manipulation is a key step for many kinds of microfluidic chips to achieve various functions, such as particle focusing and separation, fluid pumping and material synthesis. But these microfluidic experiments usually rely on large-scale signal generators for power supply, microscopes for imaging and other instruments for analysis, which hampers the portable process of microfluidic technology. Inspired by this situation, we herein designed a portable general microfluidic device (PGMD) with complex electric field regulation functions, which can accurately regulate static or continuous fluid samples. Through the graphical user interface (GUI) and modular design, the PGMD can generate multiple different electrical signals, and the micro-flow of fluid can be pumped through the built-in micropump, which can meet the requirements of most microfluidic experiments. Photos or videos of the microfluidic chip captured by the built-in microscope are received and displayed by a smartphone. We carried out a variety of microfluidic experiments such as induced-charge electroosmosis (ICEO), particle beam exit switching, thermal buoyancy flow and dielectrophoresis (DEP) on the PGMD. In addition, the PGMD can perform rapid microalgae concentration estimation in an outdoor environment, which can be used to guide microalgae cultivation, further demonstrating the development potential of this device in the field of microbial applications. Numerous results show that the PGMD has a high degree of integration and strong reliability, which expands the application of microfluidic electrokinetic experiments and provides technical support for the integration and portability of microfluidic experimental devices.

Virus Detection: From State-of-the-Art Laboratories to Smartphone-Based Point-of-Care Testing

Infectious virus outbreaks pose a significant challenge to public healthcare systems. Early and accurate virus diagnosis is critical to prevent the spread of the virus, especially when no specific vaccine or effective medicine is available. In clinics, the most commonly used viral detection methods are molecular techniques that involve the measurement of nucleic acids or proteins biomarkers. However, most clinic-based methods require complex infrastructure and expensive equipment, which are not suitable for low-resource settings. Over the past years, smartphone-based point-of-care testing (POCT) has rapidly emerged as a potential alternative to laboratory-based clinical diagnosis. This review summarizes the latest development of virus detection. First, laboratory-based and POCT-based viral diagnostic techniques are compared, both of which rely on immunosensing and nucleic acid detection. Then, various smartphone-based POCT diagnostic techniques, including optical biosensors, electrochemical biosensors, and other types of biosensors are discussed. Moreover, this review covers the development of smartphone-based POCT diagnostics for various viruses including COVID-19, Ebola, influenza, Zika, HIV, et al. Finally, the prospects and challenges of smartphone-based POCT diagnostics are discussed. It is believed that this review will aid researchers better understand the current challenges and prospects for achieving the ultimate goal of containing disease-causing viruses worldwide.

Smartphone-Based Biosensor Devices for Healthcare: Technologies, Trends, and Adoption by End-Users

Smart biosensors are becoming an important support for modern healthcare, even more so in the current context. Numerous smartphone-based biosensor developments were published in recent years, some highly effective and sensitive. However, when patents and patent applications related to smart biosensors for healthcare applications are analyzed, it is surprising to note that, after significant growth in the first half of the decade, the number of applications filed has decreased considerably in recent years. There can be many causes of this effect. In this review, we present the state of the art of different types of smartphone-based biosensors, considering their stages of development. In the second part, a critical analysis of the possible reasons why many technologies do not reach the market is presented. Both technical and end-user adoption limitations were addressed. It was observed that smart biosensors on the commercial stage are still scarce despite the great evolution that these technologies have experienced, which shows the need to strengthen the stages of transfer, application, and adoption of technologies by end-users.

Rapid quantitative assays for glucose-6-phosphate dehydrogenase (G6PD) and hemoglobin combined on a capillary-driven microfluidic chip

Rapid tests for glucose-6-phosphate dehydrogenase (G6PD) are extremely important for determining G6PD deficiency, a widespread metabolic disorder which triggers hemolytic anemia in response to primaquine and tafenoquine medication, the most effective drugs for the radical cure of malaria caused by Plasmodium parasites. Current point-of-care diagnostic devices for G6PD are either qualitative, do not normalize G6PD activity to the hemoglobin concentration, or are very expensive. In this work we developed a capillary-driven microfluidic chip to perform a quantitative G6PD test and a hemoglobin measurement within 2 minutes and using less than 2 μL of sample. We used a powerful microfluidic module to integrate and resuspend locally the reagents needed for the G6PD assay and controls. We also developed a theoretical model that successfully predicts the enzymatic reactions on-chip, guides on-chip reagent spotting and allows efficient integration of multiple assays in miniaturized formats with only a few nanograms of reagents.

Multidrug resistant tuberculosis - Diagnostic challenges and its conquering by nanotechnology approach - An overview

One of the leading killer diseases that target the parenchymal tissues of lungs is Tuberculosis. Although antimycobacterial drugs are available, there are increased incidences of drug resistance encountered in Mycobacterium sp. They have been categorized into MDR (Multidrug resistant) and XDR (Extensively drug-resistant) strains exhibiting resistance toward successive treatment regimen. This situation threatens the futuristic containment of TB with the dearth of anti-TB drugs. Nanotechnology, the emerging multidisciplinary science has presented an excellent opportunity for timely and accurate diagnosis and discrimination of Mycobacteria via its unique physio-chemical and optical characteristics. The delayed and misdiagnosis of TB and lack of sensitive diagnostic method(s) has seen a paradigm shift toward nanoparticulate system for improved diagnosis, drug delivery and reduced treatment frequency. This review article highlights the evolution of tuberculosis and its transformation to multidrug resistant strain. Further, the conventional methods for diagnosing TB and the challenges encountered in their analytical performance have been highlighted and the strategies to overcome those challenges have been briefly discussed. Smart approaches encompassing metal nanoparticles, Quantum Dots (QDs) and Field Effect Transistors (FET) based biosensor for accurate diagnosis have been critically reviewed. A decade long state-of-the-art knowledge on TB nanodiagnostics, fabrication concepts and performance characteristics has been reviewed.

Microfluidic immunoassay for detection of serological antibodies: A potential tool for rapid evaluation of immunity against SARS-CoV-2

In December 2019, coronavirus disease 2019 became a pandemic affecting more than 200 countries and territories. Millions of lives are still affected because of mandatory quarantines, which hamstring economies and induce panic. Immunology plays a major role in the modern field of medicine, especially against virulent infectious diseases. In this field, neutralizing antibodies are heavily studied because they reflect the level of infection and individuals' immune status, which are essential when considering resumption of work, flight travel, and border entry control. More importantly, it also allows evaluating the antiviral vaccine efficacy as vaccines are still known for being the ultimate intervention method to inhibit the rapid spread of virulent infectious diseases. In this Review, we first introduce the host immune response after the infection of SARS-CoV-2 and discuss the latest results using conventional immunoassays. Next, as an enabling platform for detection with sufficient sensitivity while saving analysis time and sample size, the progress of microfluidic-based immunoassays is discussed and compared based on surface modification, microfluidic kinetics, signal output, signal amplification, sample matrix, and the detection of anti-SARS-CoV-2 antibodies. Based on the overall comparison, this Review concludes by proposing the future integration of visual quantitative signals on microfluidic devices as a more suitable approach for general use and large-scale surveillance.

mHealth spectroscopy of blood hemoglobin with spectral super-resolution

Although blood hemoglobin (Hgb) testing is a routine procedure in a variety of clinical situations, noninvasive, continuous, and real-time blood Hgb measurements are still challenging. Optical spectroscopy can offer noninvasive blood Hgb quantification, but requires bulky optical components that intrinsically limit the development of mobile health (mHealth) technologies. Here, we report spectral super-resolution (SSR) spectroscopy that virtually transforms the built-in camera (RGB sensor) of a smartphone into a hyperspectral imager for accurate and precise blood Hgb analyses. Statistical learning of SSR enables us to reconstruct detailed spectra from three color RGB data. Peripheral tissue imaging with a mobile application is further combined to compute exact blood Hgb content without a priori personalized calibration. Measurements over a wide range of blood Hgb values show reliable performance of SSR blood Hgb quantification. Given that SSR does not require additional hardware accessories, the mobility, simplicity, and affordability of conventional smartphones support the idea that SSR blood Hgb measurements can be used as an mHealth method.

Accuracy improvement of electrochemical whole blood ketone sensor based on HCT compensation algorithm

In this manuscript, we demonstrated an electrochemical test strip with HCT (hematocrit) compensation algorithm to improve the accuracy of blood ketone sensor. In the conventional electrochemical sensor, the electrochemical current was directly resolved into the concentration value of the determinant without HCT compensation. For lower or higher HCT blood sample, the measured result was inaccurate. In the proposed design, the blood impedance can be measured to estimate the HCT, which was utilized to compensate the electrochemical current to resolve the more accurate concentration of determinant. The practical blood sample tests demonstrated the proposed design can provide more believable and reliable measured result in clinical point-of-care setting.

Automated screening of sickle cells using a smartphone-based microscope and deep learning

Sickle cell disease (SCD) is a major public health priority throughout much of the world, affecting millions of people. In many regions, particularly those in resource-limited settings, SCD is not consistently diagnosed. In Africa, where the majority of SCD patients reside, more than 50% of the 0.2-0.3 million children born with SCD each year will die from it; many of these deaths are in fact preventable with correct diagnosis and treatment. Here, we present a deep learning framework which can perform automatic screening of sickle cells in blood smears using a smartphone microscope. This framework uses two distinct, complementary deep neural networks. The first neural network enhances and standardizes the blood smear images captured by the smartphone microscope, spatially and spectrally matching the image quality of a laboratory-grade benchtop microscope. The second network acts on the output of the first image enhancement neural network and is used to perform the semantic segmentation between healthy and sickle cells within a blood smear. These segmented images are then used to rapidly determine the SCD diagnosis per patient. We blindly tested this mobile sickle cell detection method using blood smears from 96 unique patients (including 32 SCD patients) that were imaged by our smartphone microscope, and achieved ~98% accuracy, with an area-under-the-curve of 0.998. With its high accuracy, this mobile and cost-effective method has the potential to be used as a screening tool for SCD and other blood cell disorders in resource-limited settings.

A Cell-Phone-Based Acoustofluidic Platform for Quantitative Point-of-Care Testing

Acoustofluidic methods, with advantages including simplicity of device design, biocompatible manipulation, and low power consumption, have been touted as promising tools for point-of-care (POC) testing. Here, we report a cell-phone-based acoustofluidic platform that uses acoustic radiation forces to enrich nanoscale analytes and red and green fluorescence nanoparticles (SiO₂@R and G@SiO₂) as probes for POC visual testing. Thus, the color signals from the fluorescent probes are enhanced, and colorimetric sensitivity is significantly improved. As a POC demonstration, the acoustofluidic platform is used to detect hemoglobin (Hb) from human blood, resulting in a rapid and straightforward measurement of normal blood Hb levels. Combining an acoustofluidic-based nanoparticle-concentration platform with cell-phone-based colorimetry, our method introduces a potential pathway toward practical POC testing.

Flow Chemistry in Contemporary Chemical Sciences: A Real Variety of Its Applications

Flow chemistry is an area of contemporary chemistry exploiting the hydrodynamic conditions of flowing liquids to provide particular environments for chemical reactions. These particular conditions of enhanced and strictly regulated transport of reagents, improved interface contacts, intensification of heat transfer, and safe operation with hazardous chemicals can be utilized in chemical synthesis, both for mechanization and automation of analytical procedures, and for the investigation of the kinetics of ultrafast reactions. Such methods are developed for more than half a century. In the field of chemical synthesis, they are used mostly in pharmaceutical chemistry for efficient syntheses of small amounts of active substances. In analytical chemistry, flow measuring systems are designed for environmental applications and industrial monitoring, as well as medical and pharmaceutical analysis, providing essential enhancement of the yield of analyses and precision of analytical determinations. The main concept of this review is to show the overlapping of development trends in the design of instrumentation and various ways of the utilization of specificity of chemical operations under flow conditions, especially for synthetic and analytical purposes, with a simultaneous presentation of the still rather limited correspondence between these two main areas of flow chemistry.

Smartphone-Based Droplet Digital LAMP Device with Rapid Nucleic Acid Isolation for Highly Sensitive Point-of-Care Detection

While advances in microfluidics have enabled rapid and highly integrated detection of nucleic acid targets, the detection sensitivity is still unsatisfactory in the current POC (point-of-care) detection systems, especially for low abundance samples. In this study, a chip that integrates rapid nucleic acid extraction based on IFAST (immiscible phase filtration assisted by surface tension) and digital isothermal detection was developed to achieve highly sensitive POC detection within 60 min. Based on the interface theory, the factors influencing the interface stability of the IFAST process were studied, and the IFAST nucleic acid extraction conditions were optimized to increase the nucleic acid extraction recovery rate to 75%. Spiral mixing channel and flow-focusing droplet generation structure were designed to achieve the mixing and sample partitioning by applying negative pressure. A portable microdroplet fluorescence detection device was developed based on smartphone imaging. Validation tests were carried out for quantification of low-abundance cfDNA and detection of mutations.

Developing Gold Nanoparticles-Conjugated Aflatoxin B1 Antifungal Strips

Lateral flow immunochromatographic assays are a powerful diagnostic tool for point-of-care tests, based on their simplicity, specificity, and sensitivity. In this study, a rapid and sensitive gold nanoparticle (AuNP) immunochromatographic strip is produced for detecting aflatoxin B1 (AFB1) in suspicious fungi-contaminated food samples. The 10 nm AuNPs were encompassed by bovine serum albumin (BSA) and AFB1 antibody. Thin-layer chromatography, gel electrophoresis and nuclear magnetic resonance spectroscopy were employed for analysing the chemical complexes. Various concentrations of AFB1 antigen (0-16 ng/mL) were tested with AFB1 antibody-BSA-AuNPs (conjugated AuNPs) and then analysed by scanning electron microscopy, ultraviolet-visible spectroscopy, and Zetasizer. The results showed that the AFB1 antibody was coupled to BSA by the N-hydroxysuccinimide ester method. The AuNPs application has the potential to contribute to AFB1 detection by monitoring a visible colour change from red to purple-blue, with a detection limit of 2 ng/mL in a 96-well plate. The lateral flow immunochromatographic strip tests are rapid, taking less than 10 min., and they have a detection capacity of 10 ng/g. The smartphone analysis of strips provided the results in 3 s, with a detection limit of 0.3 ng/g for AFB1 when the concentration was below 10 ng/g. Excellent agreement was found with AFB1 determination by high-performance liquid chromatography in the determination of AFB1 among 20 samples of peanuts, corn, rice, and bread.

A Multiplexed Serologic Test for Diagnosis of Lyme Disease for Point-of-Care Use

Single multiplexed assays could replace the standard 2-tiered (STT) algorithm recommended for the laboratory diagnosis of Lyme disease if they perform with a specificity and a sensitivity superior or equal to those of the STT algorithm. We used human serum rigorously characterized to be sera from patients with acute- and convalescent-phase early Lyme disease, Lyme arthritis, and posttreatment Lyme disease syndrome, as well as the necessary controls (n = 241 samples), to select the best of 12 Borrelia burgdorferi proteins to improve our microfluidic assay (mChip-Ld). We then evaluated its serodiagnostic performance in comparison to that of a first-tier enzyme immunoassay and the STT algorithm. We observed that more antigens became positive as Lyme disease progressed from early to late stages. We selected three antigens (3Ag) to include in the mChip-Ld: VlsE and a proprietary synthetic 33-mer peptide (PepVF) to capture sensitivity in all disease stages and OspC for early Lyme disease. With the specificity set at 95%, the sensitivity of the mChip-Ld with 3Ag ranged from 80% (95% confidence interval [CI], 56% to 94%) and 85% (95% CI, 74% to 96%) for two panels of serum from patients with early Lyme disease and was 100% (95% CI, 83% to 100%) for serum from patients with Lyme arthritis; the STT algorithm detected early Lyme disease in the same two panels of serum from patients with early Lyme disease with a sensitivity of 48.5% and 75% and Lyme arthritis in serum from patients with Lyme arthritis with a sensitivity of 100%, and the specificity was 97.5% to 100%. The mChip-Ld platform outperformed the STT algorithm according to sensitivity. These results open the door for the development of a single, rapid, multiplexed diagnostic test for point-of-care use that can be designed to identify the Lyme disease stage.

Engineering Steps for Mobile Point-of-Care Diagnostic Devices

Mobile phone technology is a perfect companion for point-of-care diagnostics as they come equipped with advanced processors, high resolution cameras, and network connectivity. Despite several academic pursuits, only a few mobile phone diagnostics have been tested in the field, commercialized or achieved regulatory approval. This review will address the challenges associated with developing mobile diagnostics and suggest strategies to overcome them. We aim to provide a resource for researchers to accelerate the development of new diagnostics. Our Account includes an overview of published mobile phone diagnostics and highlights lessons learned from their approach to diagnostic development. Also, we have included recommendations from regulatory and public health agencies, such as the U.S. Food and Drug Administration and World Health Organization, to further guide researchers. We believe that the development of mobile phone point-of-care diagnostics takes place in four distinct steps: (1) Needs and Value Assessment, (2) Technology Development, (3) Preclinical Verification, and (4) Clinical Validation and Field Trials. During each step, we outline developmental strategies to help researchers avoid potential challenges. (1) Researchers commonly develop devices to maximize technical parameters such as sensitivity and time which do not necessarily translate to increased clinical impact. Researchers must focus on assessing specific diagnostic needs and the value which a potential device would offer. (2) Often, researchers claim they have developed devices for feasible implementation at the point-of-care, yet they rely on laboratory resources. Researchers must develop equipment-free devices which are agnostic to any mobile phone. (3) Another challenge researchers face is decreased performance during field evaluations relative to initial laboratory verification. Researchers must ensure that they simulate the field conditions during laboratory verification to achieve successful translation. (4) Finally, proper field testing of devices must be performed in conditions which match that of the final intended use. The future of mobile phone point-of-care diagnostic devices is bright and has the potential to radically change how patients are diagnosed. Before we reach this point, researchers must take a step backward and focus on the first-principles of basic research. The widespread adoption and rapid scaling of these devices can only be achieved once the fundamentals have been considered. The insights and strategies provided here will help researchers avoid pitfalls, streamline development and make better decisions during the development of new diagnostics. Further, we believe this Account can help push the field of mobile diagnostics toward increased productivity, leading to more approved devices and ultimately helping curb the burden of disease worldwide.

Early Detection and Treatment of Patients with Alzheimer's Disease: Future Perspectives

Alzheimer's disease affects approximately 6% of people over the age of 65 years. It is characterized as chronic degeneration of cortical neurons, with loss of memory, cognition and executive functions. As the disease progresses, it is accompanied by accumulation of amyloid plaques and neurofibrillary tangles in key areas of the brain, leading to a loss of neurogenesis and synaptic plasticity in the hippocampus, along with changes in the levels of essential neurotransmitters such as acetylcholine and glutamate. Individuals with concomitant diseases such as depression, diabetes and cardiovascular disorders have a higher risk of developing Alzheimer's disease, and those who have a healthier diet and partake in regular exercise and intellectual stimulation have a lower risk of developing the disorder. This chapter describes the advances made in early diagnosis of Alzheimer's disease as this could help to improve outcomes for the patients by facilitating earlier treatment.

Disposable Sensors in Diagnostics, Food, and Environmental Monitoring

Disposable sensors are low-cost and easy-to-use sensing devices intended for short-term or rapid single-point measurements. The growing demand for fast, accessible, and reliable information in a vastly connected world makes disposable sensors increasingly important. The areas of application for such devices are numerous, ranging from pharmaceutical, agricultural, environmental, forensic, and food sciences to wearables and clinical diagnostics, especially in resource-limited settings. The capabilities of disposable sensors can extend beyond measuring traditional physical quantities (for example, temperature or pressure); they can provide critical chemical and biological information (chemo- and biosensors) that can be digitized and made available to users and centralized/decentralized facilities for data storage, remotely. These features could pave the way for new classes of low-cost systems for health, food, and environmental monitoring that can democratize sensing across the globe. Here, a brief insight into the materials and basics of sensors (methods of transduction, molecular recognition, and amplification) is provided followed by a comprehensive and critical overview of the disposable sensors currently used for medical diagnostics, food, and environmental analysis. Finally, views on how the field of disposable sensing devices will continue its evolution are discussed, including the future trends, challenges, and opportunities.

Rapid immunodiagnostics of multiple viral infections in an acoustic microstreaming device with serum and saliva samples

There is a growing need to screen multiple infections simultaneously rather than diagnosis of one pathogen at a time in order to improve the quality of healthcare while saving initial screening time and reduce costs. This is the first demonstration of a five-step protein array assay for the multiplexed detection of HIV, HPV and HSV antibodies on an integrated microfluidic system. HIV, HPV and HSV reactive antibodies from both serum and saliva were rapidly detected by acoustic streaming-based mixing and pumping to enable an integrated, rapid and simple-to-use multiplexed assay device. We validated this device with 37 serum and saliva samples to verify reactivity of patient antibodies with HIV, HPV and HSV antigens. Our technology can be adapted with different protein microarrays to detect a variety of other infections, thus demonstrating a powerful platform to detect multiple putative protein biomarkers for rapid detection of infectious diseases. This integrated microfluidic protein array platform is the basis of a potent strategy to delay progression of primary infection, reduce the risk of co-infections and prevent onward transmission of infections by point-of-care detection of multiple pathogens in both serum and oral fluids.

Developments in Transduction, Connectivity and AI/Machine Learning for Point-of-Care Testing

We review some emerging trends in transduction, connectivity and data analytics for Point-of-Care Testing (POCT) of infectious and non-communicable diseases. The patient need for POCT is described along with developments in portable diagnostics, specifically in respect of Lab-on-chip and microfluidic systems. We describe some novel electrochemical and photonic systems and the use of mobile phones in terms of hardware components and device connectivity for POCT. Developments in data analytics that are applicable for POCT are described with an overview of data structures and recent AI/Machine learning trends. The most important methodologies of machine learning, including deep learning methods, are summarised. The potential value of trends within POCT systems for clinical diagnostics within Lower Middle Income Countries (LMICs) and the Least Developed Countries (LDCs) are highlighted.

Proteomic Studies of Psychiatric Disorders

Many diseases result from programming effects in utero. This chapter describes recent advances in proteomic studies which have improved our understanding of the underlying pathophysiological pathways in the major psychiatric disorders, resulting in the development of potential novel biomarker tests. Such tests should be based on measurement of blood-based proteins given the ease of accessibility of this medium and the known connections between the periphery and the central nervous system. Most importantly, emerging biomarker tests should be developed on lab-on-a-chip and other handheld devices to enable point-of-care use. This should help to identify individuals with psychiatric disorders much sooner than ever before, which will allow more rapid treatment options for the best possible patient outcomes.

From Point-of-Care Testing to eHealth Diagnostic Devices (eDiagnostics)

Point-of-care devices were originally designed to allow medical testing at or near the point of care by health-care professionals. Some point-of-care devices allow medical self-testing at home but cannot fully cover the growing diagnostic needs of eHealth systems that are under development in many countries. A number of easy-to-use, network-connected diagnostic devices for self-testing are needed to allow remote monitoring of patients' health. This Outlook highlights the essential characteristics of diagnostic devices for eHealth settings and indicates point-of-care technologies that may lead to the development of new devices. It also describes the most representative examples of simple-to-use, point-of-care devices that have been used for analysis of untreated biological samples.

"The Smartphone's Guide to the Galaxy": In Situ Analysis in Space

A human mission to Mars can be viewed as the apex of human technological achievement. However, to make this dream a reality several obstacles need to be overcome. One is devising practical ways to safeguard the crew health during the mission through the development of easy operable and compact sensors. Lately, several smartphone-based sensing devices (SBDs) with the purpose to enable the immediate sensitive detection of chemicals, proteins or pathogens in remote settings have emerged. In this critical review, the potential to piggyback these systems for in situ analysis in space has been investigated on application of a systematic keyword search whereby the most relevant articles were examined comprehensively and existing SBDs were divided into 4 relevant groups for the monitoring of crew health during space missions. Recently developed recognition elements (REs), which could offer the enhanced ability to tolerate those harsh conditions in space, have been reviewed with recommendations offered. In addition, the potential use of cell free synthetic biology to obtain long-term shelf-stable reagents was reviewed. Finally, a synopsis of the possibilities of combining novel SBD, RE and nanomaterials to create a compact sensor-platform ensuring adequate crew health monitoring has been provided.

3D-Printed Biosensor Arrays for Medical Diagnostics

While the technology is relatively new, low-cost 3D printing has impacted many aspects of human life. 3D printers are being used as manufacturing tools for a wide variety of devices in a spectrum of applications ranging from diagnosis to implants to external prostheses. The ease of use, availability of 3D-design software and low cost has made 3D printing an accessible manufacturing and fabrication tool in many bioanalytical research laboratories. 3D printers can print materials with varying density, optical character, strength and chemical properties that provide the user with a vast array of strategic options. In this review, we focus on applications in biomedical diagnostics and how this revolutionary technique is facilitating the development of low-cost, sensitive, and often geometrically complex tools. 3D printing in the fabrication of microfluidics, supporting equipment, and optical and electronic components of diagnostic devices is presented. Emerging diagnostics systems using 3D bioprinting as a tool to incorporate living cells or biomaterials into 3D printing is also reviewed.

Policy Considerations for Mobile Biosensors

Meeting policy requirements is essential for advancing molecular diagnostic devices from the laboratory to real-world applications and commercialization. Considering policy as a starting point in the design of new technology is a winning strategy. Rapid developments have put mobile biosensors at the frontier of molecular diagnostics, at times outpacing policymakers, and therefore offering new opportunities for breakthroughs in global health. In this Perspective we survey influential global health policies and recent developments in mobile biosensing in order to gain a new perspective for the future of the field. We summarize the main requirements for mobile diagnostics outlined by policy makers such as the World Health Organization (WHO), the World Bank, the European Union (EU), and the Food and Drug Administration (FDA). We then classify current mobile diagnostic technologies according to the manner in which the biosensor interfaces with a smartphone. We observe a trend in reducing hardware components and substituting instruments and laborious data processing steps for user-friendly apps. From this perspective we see software application developers as key collaborators for bridging the gap between policy and practice.

Infectious pathogens meet point-of-care diagnostics

The field of point-of-care (POC) diagnostics provides the rapid diagnosis of infectious diseases which is essential and critical for improving the general public health in resource-limited settings. POC platforms offer many advantages for detection of various pathogens including portability, automation, speed, cost, and efficiency. In this review, we provide an overview of the recent trends for POC diagnostics of infectious diseases with focus on portable platforms. We review here the present status of POC platforms, emphasizing in period of the past three years, then extrapolate their advance into the future applications for diagnosis of infectious pathogens.

Mobile diagnostics: next-generation technologies forin vitrodiagnostics

The emergence of a wide range of applications of smartphones along with advances in ‘liquid biopsy’ has significantly propelled medical research particularly in the field ofin vitrodiagnostics (IVD).

A smartphone-based double-channel fluorescence setup for immunoassay of a carcinoembryonic antigen using CuS nanoparticles for signal amplification

Sensitive detection of cancer biomarkers is valuable for clinical diagnosis and treatment assessment of cancers.

Point-of-Care Testing and Personalized Medicine for Metabolic Disorders

This chapter describes innovations in biomarker testing that can facilitate earlier and better treatment of patients who suffer from metabolic disorders. The use of new microfluidic devices along with miniaturized biosensors and transducers enables analysis of a single drop of a blood within the time frame of a typical visit to a doctor's office. Steps are underway so that these approaches will incorporate both biochemical and clinical data, resulting in unique bioprofiles for each patient. This will allow earlier, personalized, and more effective therapeutic options. In addition, smartphone apps for self-monitoring will be used increasingly for the best possible patient outcomes.

Smartphone-Based Dual-Modality Imaging System for Quantitative Detection of Color or Fluorescent Lateral Flow Immunochromatographic Strips

Nowadays, lateral flow immunochromatographic assays are increasingly popular as a diagnostic tool for point-of-care (POC) test based on their simplicity, specificity, and sensitivity. Hence, quantitative detection and pluralistic popular application are urgently needed in medical examination. In this study, a smartphone-based dual-modality imaging system was developed for quantitative detection of color or fluorescent lateral flow test strips, which can be operated anywhere at any time. In this system, the white and ultra-violet (UV) light of optical device was designed, which was tunable with different strips, and the Sobel operator algorithm was used in the software, which could enhance the identification ability to recognize the test area from the background boundary information. Moreover, this technology based on extraction of the components from RGB format (red, green, and blue) of color strips or only red format of the fluorescent strips can obviously improve the high-signal intensity and sensitivity. Fifty samples were used to evaluate the accuracy of this system, and the ideal detection limit was calculated separately from detection of human chorionic gonadotropin (HCG) and carcinoembryonic antigen (CEA). The results indicated that smartphone-controlled dual-modality imaging system could provide various POC diagnoses, which becomes a potential technology for developing the next-generation of portable system in the near future.

The future of viral hepatitis testing: innovations in testing technologies and approaches

A large burden of undiagnosed hepatitis virus cases remains globally. Despite the 257 million people living with chronic hepatitis B virus infection, and 71 million with chronic viraemic HCV infection, most people with hepatitis remain unaware of their infection. Advances in rapid detection technology have created new opportunities for enhancing access to testing and care, as well as monitoring of treatment. This article examines a range of other technological innovations that can be leveraged to provide more affordable and simplified approaches to testing for HBV and HCV infection and monitoring of treatment response. These include improved access to testing through alternative sampling methods (use of dried blood spots, oral fluids, self-testing) and combination rapid diagnostic tests for detection of HIV, HBV and HCV infection; more affordable options for confirmation of virological infection (HBV DNA and HCV RNA) such as point-of-care molecular assays, HCV core antigen and multi-disease polyvalent molecular platforms that make use of existing centralised laboratory based or decentralised TB and HIV instrumentation for viral hepatitis testing; and finally health system improvements such as integration of laboratory services for procurement and sample transportation and enhanced data connectivity to support quality assurance and supply chain management.

Syphilis

Treponema pallidum subspecies pallidum (T. pallidum) causes syphilis via sexual exposure or via vertical transmission during pregnancy. T. pallidum is renowned for its invasiveness and immune-evasiveness; its clinical manifestations result from local inflammatory responses to replicating spirochaetes and often imitate those of other diseases. The spirochaete has a long latent period during which individuals have no signs or symptoms but can remain infectious. Despite the availability of simple diagnostic tests and the effectiveness of treatment with a single dose of long-acting penicillin, syphilis is re-emerging as a global public health problem, particularly among men who have sex with men (MSM) in high-income and middle-income countries. Syphilis also causes several hundred thousand stillbirths and neonatal deaths every year in developing nations. Although several low-income countries have achieved WHO targets for the elimination of congenital syphilis, an alarming increase in the prevalence of syphilis in HIV-infected MSM serves as a strong reminder of the tenacity of T. pallidum as a pathogen. Strong advocacy and community involvement are needed to ensure that syphilis is given a high priority on the global health agenda. More investment is needed in research on the interaction between HIV and syphilis in MSM as well as into improved diagnostics, a better test of cure, intensified public health measures and, ultimately, a vaccine.

Point-of-care diagnostics to improve maternal and neonatal health in low-resource settings

Each day, approximately 830 women and 7400 newborns die from complications during pregnancy and childbirth. Improving maternal and neonatal health will require bringing rapid diagnosis and treatment to the point of care in low-resource settings. However, to date there are few diagnostic tools available that can be used at the point of care to detect the leading causes of maternal and neonatal mortality in low-resource settings. Here we review both commercially available diagnostics and technologies that are currently in development to detect the leading causes of maternal and neonatal mortality, highlighting key gaps in development where innovative design could increase access to technology and enable rapid diagnosis at the bedside.

Point-of-care testing: applications of 3D printing

Point-of-care testing (POCT) devices fulfil a critical need in the modern healthcare ecosystem, enabling the decentralized delivery of imperative clinical strategies in both developed and developing worlds. To achieve diagnostic utility and clinical impact, POCT technologies are immensely dependent on effective translation from academic laboratories out to real-world deployment. However, the current research and development pipeline is highly bottlenecked owing to multiple restraints in material, cost, and complexity of conventionally available fabrication techniques. Recently, 3D printing technology has emerged as a revolutionary, industry-compatible method enabling cost-effective, facile, and rapid manufacturing of objects. This has allowed iterative design-build-test cycles of various things, from microfluidic chips to smartphone interfaces, that are geared towards point-of-care applications. In this review, we focus on highlighting recent works that exploit 3D printing in developing POCT devices, underscoring its utility in all analytical steps. Moreover, we also discuss key advantages of adopting 3D printing in the device development pipeline and identify promising opportunities in 3D printing technology that can benefit global health applications.

3D printed microfluidic mixer for point-of-care diagnosis of anemia

3D printing has been an emerging fabrication tool in prototyping and manufacturing. We demonstrated a 3D microfluidic simulation guided computer design and 3D printer prototyping for quick turnaround development of microfluidic 3D mixers, which allows fast self-mixing of reagents with blood through capillary force. Combined with smartphone, the point-of-care diagnosis of anemia from finger-prick blood has been successfully implemented and showed consistent results with clinical measurements. Capable of 3D fabrication flexibility and smartphone compatibility, this work presents a novel diagnostic strategy for advancing personalized medicine and mobile healthcare.

Application of nanodiagnostics in point-of-care tests for infectious diseases

Although tremendous efforts have been put into the treatment of infectious diseases to prevent epidemics and mortality, it is still one of the major health care issues that have a profound impact on humankind. Therefore, the development of specific, sensitive, accurate, rapid, low-cost, and easy-to-use diagnostic tools is still in urgent demand. Nanodiagnostics, defined as the application of nanotechnology to medical diagnostics, can offer many unique opportunities for more successful and efficient diagnosis and treatment for infectious diseases. In this review, we provide an overview of the nanodiagnostics for infectious diseases from nanoparticle-based, nanodevice-based, and point-of-care test (POCT) platforms. Most importantly, emphasis focused on the recent trends in the nanotechnology-based POCT system. The current state-of-the-art and most promising point-of-care nanodiagnostic technologies, including miniaturized diagnostic magnetic resonance platform, magnetic barcode assay system, cell phone-based polarized light microscopy platform, cell phone-based dongle platform, and paper-based POCT platform, for infectious diseases were fully examined. The limitations, challenges, and future trends of the nanodiagnostics in POCTs for infectious diseases are also discussed.

An automated and portable microfluidic chemiluminescence immunoassay for quantitative detection of biomarkers

Microfluidic platforms capable of automated, rapid, sensitive, and quantitative detection of biomarkers from patient samples could make a major impact on clinical or point-of-care (POC) diagnosis. In this work, we realize an automated diagnostic platform composed of two main components: (1) a disposable, self-contained, and integrated microfluidic chip and (2) a portable instrument that carries out completely automated operations. To demonstrate its potential for real-world application, we use injection molding for mass fabrication of the main components of disposable microfluidic chips. The assembled three-layered chip with on-chip mechanical valves for fluid control consists of (1) a top silicone fluidic layer with embedded zigzag microchannels, reagent reservoirs and a negative pressure port, (2) a middle tinfoil layer with patterned antibody/antigen stripes, and (3) a bottom silicone substrate layer with waste reservoirs. The versatility of the microfluidics-based system is demonstrated by implementation of a chemiluminescence immunoassay for quantitative detection of C-reactive protein (CRP) and testosterone in real clinical samples. This lab-on-a-chip platform with features of quantitation, portability and automation provides a promising strategy for POC diagnosis.

Turning the Page: Advancing Paper-Based Microfluidics for Broad Diagnostic Application

Infectious diseases are a major global health issue. Diagnosis is a critical first step in effectively managing their spread. Paper-based microfluidic diagnostics first emerged in 2007 as a low-cost alternative to conventional laboratory testing, with the goal of improving accessibility to medical diagnostics in developing countries. In this review, we examine the advances in paper-based microfluidic diagnostics for medical diagnosis in the context of global health from 2007 to 2016. The theory of fluid transport in paper is first presented. The next section examines the strategies that have been employed to control fluid and analyte transport in paper-based assays. Tasks such as mixing, timing, and sequential fluid delivery have been achieved in paper and have enabled analytical capabilities comparable to those of conventional laboratory methods. The following section examines paper-based sample processing and analysis. The most impactful advancement here has been the translation of nucleic acid analysis to a paper-based format. Smartphone-based analysis is another exciting development with potential for wide dissemination. The last core section of the review highlights emerging health applications, such as male fertility testing and wearable diagnostics. We conclude the review with the future outlook, remaining challenges, and emerging opportunities.

Multiplex Biomarker Approaches to Enable Point-of-Care Testing and Personalized Medicine

This chapter describes how current and future innovations driven by application of multiplex biomarker techniques can help in earlier and more efficacious treatment of patients, suffering from the world's most devastating and costly diseases. The application of new miniaturized biosensors and transducers will enable point-of-care testing by facilitating analysis of a single drop of a blood within the time span of a visit to the doctor's office. It is anticipated that the scoring algorithms used with future tests will incorporate both biochemical and clinical data, resulting in specific profiles for each patient or tested subject to enable personalized medicine approaches.

An ultrasensitive chemiluminescence aptasensor for indirect hemin detection based on aptamer recognition materials

MGO@H-Atp@Co-PP polymers were successfully prepared and used to construct a MGO@H-Atp@Co-PP-CL aptasensor.

Microfluidics-based point-of-care test for serodiagnosis of Lyme Disease

Currently, diagnostic testing for Lyme disease is done by determination of the serologic responses to Borrelia burgdorferi antigens, with the exception of the early localized phase of disease where diagnosis must be done clinically. Here, we describe the use of microfluidics technology to develop a multiplexed rapid lab-on-a-chip point of care (POC) assay for the serologic diagnosis of human Lyme disease. Following ELISA screening of 12 candidate antigens, we tested 8 on a microfluidic diagnostic system, called mChip-Ld, using a set of 60 serological samples. The mChip-Ld test, which can be performed in 15 minutes at the point of care, showed promising performance for detection of antibodies to B. burgdorferi using the PPO triplex test (rP100 + PepVF + rOspC-K, AUC of 0.844) compared to a gold-standard reference of culture confirmed clinical samples. The performance is comparable to the commonly used C6 peptide by lab-based ELISA. In addition, the mChip-Ld test showed promising performance for early-stage diagnosis of the disease using the antigen OspC-K (sensitivity and specificity of 84% and 92%, respectively; AUC of 0.877). Overall, this study underscores the potential of using microfluidics to aid the diagnosis of Lyme disease at the point of care.