Smartphone-Powered Electrochemical Dongle for Point-of-Care Monitoring of Blood β-Ketone

Advancements in Biosensors for Point-of-Care Testing of Nucleic Acid

Rapid, low-cost and high-specific diagnosis based on nucleic acid detection is pivotal in both detecting and controlling various infectious diseases, effectively curbing their spread. Moreover, the analysis of circulating DNA in whole blood has emerged as a promising noninvasive strategy for cancer diagnosis and monitoring. Although traditional nucleic acid detection methods are reliable, their time-consuming and intricate processes restrict their application in rapid field assays. Consequently, an urgent emphasis on point-of-care testing (POCT) of nucleic acids has arisen. POCT enables timely and efficient detection of specific sequences, acting as a deterrent against infection sources and potential tumor threats. To address this imperative need, it is essential to consolidate key aspects and chart future directions in POCT biosensors development. This review aims to provide an exhaustive and meticulous analysis of recent advancements in POCT devices for nucleic acid diagnosis. It will comprehensively compare these devices across crucial dimensions, encompassing their integrated structures, the synthesized nanomaterials harnessed, and the sophisticated detection principles employed. By conducting a rigorous evaluation of the current research landscape, this review will not only spotlight achievements but also identify limitations, offering valuable insights into the future trajectory of nucleic acid POCT biosensors. Through this comprehensive analysis, the review aspires to serve as an indispensable guide for fostering the development of more potent biosensors, consequently fostering precise and efficient POCT applications for nucleic acids.

Pursuing precision in medicine and nutrition: the rise of electrochemical biosensing at the molecular level

In the era that we seek personalization in material things, it is becoming increasingly clear that the individualized management of medicine and nutrition plays a key role in life expectancy and quality of life, allowing participation to some extent in our welfare and the use of societal resources in a rationale and equitable way. The implementation of precision medicine and nutrition are highly complex challenges which depend on the development of new technologies able to meet important requirements in terms of cost, simplicity, and versatility, and to determine both individually and simultaneously, almost in real time and with the required sensitivity and reliability, molecular markers of different omics levels in biofluids extracted, secreted (either naturally or stimulated), or circulating in the body. Relying on representative and pioneering examples, this review article critically discusses recent advances driving the position of electrochemical bioplatforms as one of the winning horses for the implementation of suitable tools for advanced diagnostics, therapy, and precision nutrition. In addition to a critical overview of the state of the art, including groundbreaking applications and challenges ahead, the article concludes with a personal vision of the imminent roadmap.

Construction of a Novel Semiautomated Electrochemical Sensor Array Platform and Its Application in Multiplexed Monitoring of Antibiotic Therapy

At present, traditional analytical methods suffer from issues such as complex operation, expensive equipment, and a lengthy testing time. Electrochemical sensors have shown great advantages and application potential as an alternative solution. In this study, we proposed a novel semiautomated electrochemical sensor array (SAESA) platform. The sensor array was fabricated using screen-printed technology with a tubular design where all electrodes were printed on the inner wall. The integration of the tubular sensor array with a pipet allows for a semiautomated process including sampling and rinsing, which simplifies operation and reduces overall time. Each working electrode in the tubular sensor array underwent distinct decoration to get specific sensing responses toward the target analytes in a mixture environment (e.g., blood samples). To demonstrate the applicability of the developed sensing platform for simultaneous multianalyte detection, we chose antibiotic treatment for inflammatory infection as a model scenario and continuously measured three biomarkers, namely, tigecycline (TGC), procalcitonin (PCT), and alanine aminotransferase (ALT). The detection limits were 0.3 μM, 0.3 ng/L, and 2.76 U/L, respectively. The developed semiautomated electrochemical sensor array exhibits characteristics such as rapid and simple operation, portability, good selectivity, and excellent stability.

Emerging trends in nanomaterial design for the development of point-of-care platforms and practical applications

Nanomaterials and nanotechnology offer promising opportunities in point-of-care (POC) diagnostics and therapeutics due to their unique physical and chemical properties. POC platforms aim to provide rapid and portable diagnostic and therapeutic capabilities at the site of patient care, offering cost-effective solutions. Incorporating nanomaterials with distinct optical, electrical, and magnetic properties can revolutionize the POC industry, significantly enhancing the effectiveness and efficiency of diagnostic and theragnostic devices. By leveraging nanoparticles and nanofibers in POC devices, nanomaterials have the potential to improve the accuracy and speed of diagnostic tests, making them more practical for POC settings. Technological advancements, such as smartphone integration, imagery instruments, and attachments, complement and expand the application scope of POCs, reducing invasiveness by enabling analysis of various matrices like saliva and breath. These integrated testing platforms facilitate procedures without compromising diagnosis quality. This review provides a summary of recent trends in POC technologies utilizing nanomaterials and nanotechnologies for analyzing disease biomarkers. It highlights advances in device development, nanomaterial design, and their applications in POC. Additionally, complementary tools used in POC and nanomaterials are discussed, followed by critical analysis of challenges and future directions for these technologies.

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.

Advances in the Measurement of Polymeric Colorimetric Sensors Using Portable Instrumentation: Testing the Light Influence

Sustainable and green sensors based on polydimethyl siloxane (PDMS) or cellulose polymers, as a case of study of the use of portable instrumentation joined to a smartphone, have been tested. A smartphone camera was used to obtain images and was also coupled to a minispectrometer, without and with an optical fiber probe to register spectra. To study light influence on the analytical signal, light-emitting diode (LED), halogen light and daylight have been assayed. A corrective palette of 24 colors and a set with 45 colors from different color ranges were used as the validation set. The results indicated that halogen light was the best option to obtain the spectra. However, for digital image analysis, it was the LED light that gave a greater approximation of the RGB values of the real colors. Based on these results, the spectra and the RGB components of PDMS solid sensors doped with 1,2-naphtoquinone-4-sulfonate (NQS) for the determination of ammonium in water or urea in urine, PDMS doped with Griess reagent for developing the assay of nitrite in waters and cellulose sensors for the determination of hydrogen sulfide in the atmospheres have been obtained. The results achieved were good in terms of sensitivity and linearity and were comparable to those obtained using a laboratory benchtop instrument. Several rules for selecting the most suitable light source to obtain the spectra and/or images have been established and an image correction method has been introduced.

In Vivo Detection of Glutamate in Tomatoes by an Enzyme-Based Electrochemical Biosensor

The in vivo and on-site detection of key physiology parameters in plants will be of great relevance for precision agriculture and food technology. In this work, a sensitive enzymatic glutamate sensor was successfully developed. To enhance the conductivity and catalytic ability and to fix the glutamate oxidase, Au-Pt nanoparticles were first deposited on screen-printed electrodes, and then carboxylated graphene oxide and carboxylated multiwalled carbon nanotubes were fabricated for the synthesis of the electrode. The detection range of the glutamate sensor is widest (2 μM to 16 mM) up to date, and its detection limit is relatively low (0.14 μM). A number of standard curves were built in the pH range of 3.5-7.5, which can be applied in various plants and fruits. Using this sensor, the glutamate level in tomatoes was determined in vivo. This glutamate sensor has important practical value in precision agriculture. Our strategy also provides a way to establish the detection modes for other biomolecules in plants.

Nanochannel Array on Electrochemically Polarized Screen Printed Carbon Electrode for Rapid and Sensitive Electrochemical Determination of Clozapine in Human Whole Blood

Rapid and highly sensitive determination of clozapine (CLZ), a psychotropic drug for the treatment of refractory schizophrenia, in patients is of great significance to reduce the risk of disease recurrence. However, direct electroanalysis of CLZ in human whole blood remains a great challenge owing to the remarkable fouling that occurs in a complex matrix. In this work, a miniaturized, integrated, disposable electrochemical sensing platform based on the integration of nanochannel arrays on the surface of screen-printed carbon electrodes (SPCE) is demonstrated. The device achieves high determination sensitivity while also offering the electrode anti-fouling and anti-interference capabilities. To enhance the electrochemical performance of SPCE, simple electrochemical polarization including anodic oxidation and cathodic reduction is applied to pretreat SPCE. The electrochemically polarized SPCE (p-SPCE) exhibits an enhanced electrochemical peak signal toward CLZ compared with bare SPCE. An electrochemically assisted self-assembly method (EASA) is utilized to conveniently electrodeposit a vertically ordered mesoporous silica nanomembrane film (VMSF) on the p-SPCE, which could further enrich CLZ through electrostatic interactions. Owing to the dual signal amplification based on the p-SPCE and VMSF nanochannels, the developed VMSF/SPCE sensor enables determination of CLZ in the range from 50 nM to 20 μM with a low limit of detection (LOD) of 28 nM (S/N = 3). Combined with the excellent anti-fouling and anti-interference abilities of VMSF, direct and sensitive determination of CLZ in human blood is also achieved.

Smartphone-based mobile biosensors for the point-of-care testing of human metabolites

Rapid, accurate, portable and quantitative profiling of metabolic biomarkers is of great importance for disease diagnosis and prognosis. The recent development in the optical and electric biosensors based on the smartphone is promising for profiling of metabolites with advantages of rapid, reliability, accuracy, low-cost and multi-analytes analysis capability. In this review, we introduced the optical biosensing platforms including colorimetric, fluorescent and chemiluminescent sensing, and electrochemical biosensing platforms including wired and wireless communication. Challenges and future perspectives desired for reliable, accurate, cost-effective, and multi-functions smartphone-based biosensing systems were also discussed. We envision that such smartphone-based biosensing platforms will allow daily and comprehensive metabolites monitoring in the future, thus unlocking the potential to transform clinical diagnostics into non-clinical self-testing. We also believed that this progress report will encourage future research to develop advanced, integrated and multi-functional smartphone-based Point-of-Care testing (POCT) biosensors for the monitoring and diagnosis as well as personalized treatments of a spectrum of metabolic-disorder related diseases.

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.

A Dual-Channel Intelligent Point-of-Care Testing System for Soluble Programmed Death-1 and Programmed Death-Ligand 1 Detection Based on Folding Paper-Based Immunosensors

Both programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) are important proteins in cancer immunotherapy. Soluble forms (sPD-1 and sPD-L1) have potential for determining treatment and prognosis monitoring. However, there is a lack of detection methods for point-of-care testing (POCT) of these two proteins, so a low-cost rapid detection platform is urgently needed. To solve this problem, a dual-channel electrochemical platform, including a folding paper-based immunosensor and a POCT system for rapid simultaneous detection of these two proteins was designed and fabricated. The immunosensor consists of a three-electrode system and a reaction cell. The surface of the working electrode was modified with nanocomposites synthesized from amine-functionalized single-walled carbon nanotubes, new methylene blue, and gold nanoparticles. Antibodies to sPD-1 and sPD-L1 were also immobilized on the working electrode surface. A differential pulse voltammetry electrochemical method was adopted. The immunosensor was able to detect sPD-1 and sPD-L1 in the ranges of 50 pg/mL to 50 ng/mL and 5 pg/mL to 5 ng/mL, respectively. The limits of detection were 10 and 5 pg/mL. Using this detection platform, sPD-1 and sPD-L1 in plasma were detected by both enzyme-linked immunosorbent assay and the immunosensor, which has good application potential.

Smartphone-Based Electrochemical System for Biosensors and Biodetection

With the advantages of high popularity, convenient operation, open-source operation systems, high resolution imaging, and excellent computing capabilities, smartphones have been widely used as the core of detection system for calculation, control, and real-time display. Hence, smartphones play an important role in electrochemical detection and optical detection. Smartphone-based electrochemical systems were combined with screen-printed electrode and interdigital electrodes for in situ detection. The electrodes were modified with biomaterials, chemical materials, and nanomaterials for biosensors and biodetection, such as 3-amino phenylboronic acid nanocomposites, graphene, gold nanoparticles, zinc oxide nanoparticles, carbon nanotubes, proteins, peptides, and antibodies. With the modified electrodes, the smartphone-based impedance system was used to detect acetone, bovine serum albumin, human serum albumin, and trinitrotoluene, while smartphone-based amperometric system was employed to monitor glucose, ascorbic acid, dopamine, uric acid, and levodopa. The smartphone-based electrochemical system for biosensors and biodetection has provided miniaturized and portable alternative for diagnosis, which is promising to find application in point-of-care testing (POCT).

Smartphone-based photochemical sensor for multiplex determination of glucose, uric acid, and total cholesterol in fingertip blood

The physical picture of the proposed system, which consists of a photochemical dongle, a cloud-enabled smartphone, and disposable test strips.

Testing and diagnosis of SARS-CoV-2 infection

The recent outbreak of the coronavirus disease 2019 (COVID-19) has rapidly spread around the world since its discovery in China, in December 2019. The current standard method for determining whether a patient is infected with the SARS-CoV-2 virus involves taking a nasal or throat swab sample, which is then sent to laboratories for testing. The laboratories then use polymerase chain reaction (PCR)-based technology on respiratory specimens remain the gold standard to determine if the genetic material of the virus is present in the sample and use this information to diagnose the patient. However, serologic immunoassays and point-of-care technologies are rapidly emerging with high specificity and sensitivity as well. Even if there are excellent techniques for diagnosing symptomatic patients with COVID-19 in equipped laboratories, critical gaps still exist in the screening of asymptomatic individuals who are in the incubation phase of the virus, as well as in the accurate determination of live virus shedding during convalescence to inform decisions for ending isolation.

Integrated Wearable Sensors for Sensing Physiological Pressure Signals and β-Hydroxybutyrate in Physiological Fluids

Flexible and wearable sensors have attracted much attention for their applications in health monitoring and the human-machine interaction. The most studied wearable sensors have been demonstrated for sensing a limited range of metabolites such as ions, glucose, uric acid, lactate, etc. Both sweat and urine contain numerous other physiologically relevant metabolites indicative of health and wellness. This work demonstrates the use of the wearable sensor for the detection of β-hydroxybutyrate (HB) in sweat. HB is an important biomarker for diabetic ketoacidosis, a condition caused by the accumulation of ketone bodies in hyperglycemia or metabolic acidosis patients. Herein, we fabricated an integrated sensing system coupling an HB detection chamber with a serpentine electrode for sensing physiological signals such as pulse beat, vocal cord vibration, etc. The real-time HB detection was based on a β-hydroxybutyrate dehydrogenase enzymatic reaction. The stability of the enzyme and the cofactor couple was achieved by cross-linking networks and a redox mediator, thereby achieving high selectivity and low detection limits to HB in urine and sweat. The dual-functional sensor was integrated with a signal processing circuitry for signal transduction, conditioning, processing, wireless transmission, and real-time convenient health monitoring display to a smartphone via home-developed software.

5G-Enabled intelligent construction of a chest pain center with up-conversion lateral flow immunoassay

Acute myocardial infarction (AMI) has become a worldwide health problem because of its rapid onset and high mortality. Cardiac troponin I (cTnI) is the gold standard for diagnosis of AMI, and its rapid and accurate detection is critical for early diagnosis and management of AMI. Using a lateral flow immunoassay with upconverting nanoparticles as fluorescent probes, we developed an up-conversion fluorescence reader capable of rapidly quantifying the cTnI concentration in serum based upon the fluorescence intensity of the test and control lines on the test strip. Reliable detection of cTnI in the range 0.1-50 ng mL^-1 could be achieved in 15 min, with a lower detection limit of 0.1 ng mL^-1. The reader was also adapted for use on a 5th generation (5G) mobile network enabled intelligent chest pain center. Through Bluetooth wireless communication, the results achieved using the reader on an ambulance heading to a central hospital could be transmitted to a 5G smartphone and uploaded for real-time edge computing and cloud storage. An application in the 5G smartphone allows users to upload their medical information to establish dedicated electronic health records and doctors to monitor patients' health status and provide remote medical services. Combined with mobile internet and big data, the 5G-enabled intelligent chest pain center with up-conversion lateral flow immunoassay may predict the onset of AMI and save valuable time for patients suffering an AMI.

Integrated hand-held electrochemical sensor for multicomponent detection in urine

Electrochemical sensors have shown great advantage and application potential in point-of-care testing (POCT) related scenarios. However, some fatal problems plague its widespread utilization, which include the susceptibility of sensors to interference in real samples (e.g. pH), the contradiction between the limited objects detectable for most sensors and the requirement of multi-target analysis in most cases, and the complicated procedures in sensor preparation as well as in routine use. This paper contributed a tip-like electrochemical sensor prototype. By integrated with a commercial pipettor, it fulfilled semi-automatic assay procedure of sampling, detection and rinsing, thus saving operational time and manual work. The tip sensor owns the property of simple fabrication and is free from any modification of extra bio/chem materials. Moreover, built on multiple electrochemical signal outputs including open circuit potential, peak current and potential of specific electrochemical reaction, this work established a novel multi-component sensing strategy, wherein detection of uric acid (UA), urea and pH in urine samples was realized by using one single working electrode. The detection range for the above targets is 5.0~600 μM for UA, 4.0~8.0 for pH and 0.5~7.0 mM for urea with the detection limits (S/N = 3) of 0.05 μM for UA and 5.4 μM for urea, and the sensitivity of pH assay is 73 mV/pH. Notably, as variation of sample pH has impact on electrochemical analysis, the pH-related parameter was introduced for calibration to diminish such interference. The developed tip sensor and the novel sensing strategy may open a new window for electrochemical technology and broaden its application in POCT.

Highly Sensitive Electrochemical Sensor for Diagnosis of Diabetic Ketoacidosis (DKA) by Measuring Ketone Bodies in Urine

In this report, we present an enzyme deposited Au electrode for an electrochemical measurement of acetylacetic acid (AcAc) in urine. The electrode has an immobilized layer of a mixture of D-β-hydroxybutyrate dehydrogenase (HBDH) and nicotinamide adenine dinucleotide (NADH) as sensing material to investigate its electroanalytical properties by means of cyclic voltammetry (CV). The modified electrodes are used for the detection of AcAc and present a linear current increase when the AcAc concentration increases. The electrode presents a limit of detection (LOD) of 6.25 mg/dL in the range of 6.25-100 mg/dL for investigation of clinical relevance. Finally, the electrode was evaluated using 20 patient samples. The measured results of urine ketone by the developed electrode were compared with the clinical results from a commercial kit, and the analysis showed good agreement. The proposed electrode was demonstrated to be a very promising platform as a miniaturized electrochemical analyzer for point-of-care monitoring of the critical biochemical parameters such as urine ketone.

A Portable Smartphone-Based Laryngoscope System for High-Speed Vocal Cord Imaging of Patients With Throat Disorders: Instrument Validation Study

Background

Currently, high-speed digital imaging (HSDI), especially endoscopic HSDI, is routinely used for the diagnosis of vocal cord disorders. However, endoscopic HSDI devices are usually large and costly, which limits access to patients in underdeveloped countries and in regions with inadequate medical infrastructure. Modern smartphones have sufficient functionality to process the complex calculations that are required for processing high-resolution images and videos with a high frame rate. Recently, several attempts have been made to integrate medical endoscopes with smartphones to make them more accessible to people in underdeveloped countries.

Objective

This study aims to develop a smartphone adaptor for endoscopes, which enables smartphone-based vocal cord imaging, to demonstrate the feasibility of performing high-speed vocal cord imaging via the high-speed imaging functions of a high-performance smartphone camera, and to determine the acceptability of the smartphone-based high-speed vocal cord imaging system for clinical applications in developing countries.

Methods

A customized smartphone adaptor optical relay was designed for clinical endoscopy using selective laser melting–based 3D printing. A standard laryngoscope was attached to the smartphone adaptor to acquire high-speed vocal cord endoscopic images. Only existing basic functions of the smartphone camera were used for HSDI of the vocal cords. Extracted still frames were observed for qualitative glottal volume and shape. For image processing, segmented glottal and vocal cord areas were calculated from whole HSDI frames to characterize the amplitude of the vibrations on each side of the glottis, including the frequency, edge length, glottal areas, base cord, and lateral phase differences over the acquisition time. The device was incorporated into a preclinical videokymography diagnosis routine to compare functionality.

Results

Smartphone-based HSDI with the smartphone-endoscope adaptor could achieve 940 frames per second and a resolution of 1280 by 720 frames, which corresponds to the detection of 3 to 8 frames per vocal cycle at double the spatial resolution of existing devices. The device was used to image the vocal cords of 4 volunteers: 1 healthy individual and 3 patients with vocal cord paralysis, chronic laryngitis, or vocal cord polyps. The resultant image stacks were sufficient for most diagnostic purposes. The cost of the device including the smartphone was lower than that of existing HSDI devices. The image processing and analytics demonstrated the successful calculation of relevant diagnostic variables from the acquired images. Patients with vocal pathologies were easily differentiable in the quantitative data.

Conclusions

A smartphone-based HSDI endoscope system can function as a point-of-care clinical diagnostic device. The resulting analysis is of higher quality than that accessible by videostroboscopy and promises comparable quality and greater accessibility than HSDI. In particular, this system is suitable for use as an accessible diagnostic tool in underdeveloped areas with inadequate medical service infrastructure.

Wearable and Mobile Sensors for Personalized Nutrition

While wearable and mobile chemical sensors have experienced tremendous growth over the past decade, their potential for tracking and guiding nutrition has emerged only over the past three years. Currently, guidelines from doctors and dietitians represent the most common approach for maintaining optimal nutrition status. However, such recommendations rely on population averages and do not take into account individual variability in responding to nutrients. Precision nutrition has recently emerged to address the large heterogeneity in individuals' responses to diet, by tailoring nutrition based on the specific requirements of each person. It aims at preventing and managing diseases by formulating personalized dietary interventions to individuals on the basis of their metabolic profile, background, and environmental exposure. Recent advances in digital nutrition technology, including calories-counting mobile apps and wearable motion tracking devices, lack the ability of monitoring nutrition at the molecular level. The realization of effective precision nutrition requires synergy from different sensor modalities in order to make timely reliable predictions and efficient feedback. This work reviews key opportunities and challenges toward the successful realization of effective wearable and mobile nutrition monitoring platforms. Non-invasive wearable and mobile electrochemical sensors, capable of monitoring temporal chemical variations upon the intake of food and supplements, are excellent candidates to bridge the gap between digital and biochemical analyses for a successful personalized nutrition approach. By providing timely (previously unavailable) dietary information, such wearable and mobile sensors offer the guidance necessary for supporting dietary behavior change toward a managed nutritional balance. Coupling of the rapidly emerging wearable chemical sensing devices-generating enormous dynamic analytical data-with efficient data-fusion and data-mining methods that identify patterns and make predictions is expected to revolutionize dietary decision-making toward effective precision nutrition.

Development of an Integrated Optical Sensor for Determination of β-Hydroxybutyrate Within the Microplatform

Ketone bodies (acetoacetate, beta-hydroxybutyrate (βHB), acetone) are generated as a result of fatty acid oxidation in the liver and exist at low concentrations in urine and blood. Elevated concentrations can indicate health problems such as diabetes, childhood hypoglycemia, alcohol, or salicylate poisoning. Development of portable and cost-effective bedside point-of-care (POC) tests to detect such compounds can help to reduce the risk of disease progression. In this study, βHB was chosen as a model molecule for developing an optical sensor-integrated microplatform. Prior to sensor optimization, βHB levels were measured at a concentration range of 0.02 and 0.1 mM spectrophotometrically, which is far below the reported elevated ranges of 1-2 mM and resulting absorbance changes were converted into an Arduino microcontroller code for the correlation. Measurements performed with the designed integrated microplatform were found significant. Integrated microplatform was verified with the benchtop spectrophotometer. Measurements between 0.02 and 0.1 mM substrate concentration were found highly sensitive with "y = 0.7347x + 0.00184" with R² value of 0.9796, and the limit of detection was determined as 0.02 mM. Based on these results, the proposed system will allow on-site and early intervention.

Scaling the Analytical Information Given by Several Types of Colorimetric and Spectroscopic Instruments Including Smartphones: Rules for Their Use and Establishing Figures of Merit of Solid Chemosensors

The analytical information given by different types of instruments was scaled in order to establish suitably the figures of merit of a given methodology based on color measurements. Different lab and portable instruments, including smartphones with and without a miniaturized spectrophotometer accessory, have been tested. In order to obtain broad information and using objective criteria, these instruments have been compared from (1) the analytical point of view, considering mainly the detection limit (limits of detection [LODs]), selectivity, accuracy and intra- and interday precision, size, components, and costs; and (2) the environmental point of view, based on their footprint as kilograms of CO₂. No significant differences in the precision were obtained with RSD (%) values lower than 10% for all of the instruments, but the achieved values of LOD, selectivity, accuracy, and cost were different. Footprints of CO₂ were better for portable instrumentation, especially for smartphones. Three solid chemosensors made of different materials (PDMS, paper, or nylon) have been tested for the determination of ammonia and hydrogen sulfide at different concentration levels (ppb levels). As a result of this study, some rules for selecting the instrument for obtaining the required information have been established. Two apps have been developed for quantitation by smartphones, one for working with RGB values and the other for spectra obtained by the miniaturized spectrophotometer coupled to a smartphone.

Smartphone-Enabled Paper-Based Hemoglobin Sensor for Extreme Point-of-Care Diagnostics

We report a simple, affordable (∼0.02 US $/test), rapid (within 5 min), and quantitative paper-based sensor integrated with smartphone application for on-spot detection of hemoglobin (Hgb) concentration using approximately 10 μL of finger-pricked blood. Quantitative analytical colorimetry is achieved via an Android-based application (Sens-Hb), integrating key operational steps of image acquisition, real-time analysis, and result dissemination. Further, feedback from the machine learning algorithm for adaptation of calibration data offers consistent dynamic improvement for precise predictions of the test results. Our study reveals a successful deployment of the extreme point-of-care test in rural settings where no infrastructural facilities for diagnostics are available. The Hgb test device is validated both in the controlled laboratory environment (n = 200) and on the field experiments (n = 142) executed in four different Indian villages. Validation results are well correlated with the pathological gold standard results (r = 0.9583) with high sensitivity and specificity for the healthy (n = 136) (>11 g/dL) (specificity: 97.2%), mildly anemic (n = 55) (<11 g/dL) (sensitivity: 87.5%, specificity: 100%), and severely anemic (n = 9) (<7 g/dL) (sensitivity: 100%, specificity: 100%) samples. Results from field trials reveal that only below 5% cases of the results are interpreted erroneously by classifying mildly anemic patients as healthy ones. On-field deployment has unveiled the test kit to be extremely user friendly that can be handled by minimally trained frontline workers for catering the needs of the underserved communities.

Real-time monitoring of geosmin based on an aptamer-conjugated graphene field-effect transistor

In this paper, we propose a novel field-effect transistor (FET) using graphene, which is a two-dimensional (2D) nanomaterial, capable of evaluating water quality, and immobilizing the surface of a graphene micropatterned transistor with a highly responsive bioprobe for a water contamination indicator, geosmin, with high selectivity. A high-quality bioprobe-immobilized graphene FET (GFET) was fabricated for the real-time monitoring of geosmin using a liquid-gate measurement configuration. Immobilization was confirmed by measuring the change in the electrical characteristics of the platform (slope of the current-voltage (I-V) curve) and fluorescence images. In addition, a selectivity test showed remarkable implementation of the highly sensitive sensing platform with an insignificant signal when a nontarget was added. Using the fabricated device, the linear range for geosmin detection was determined to be from 0.01 nM - 1 μM with a detection limit of 0.01 nM. In addition, geosmin concentrations as low as 10 nM could be determined from river water samples with the sensor platform. This sensor can be utilized to immediately determine the presence of odorous substances by analyzing a water supply source without additional pretreatment. Another advantage is that the sensor device is a promising tool that does not have special equipment that requirs careful maintenance. In addition, the device provides a new platform for detecting harmful substances in various water sources by varying the bioprobes that are empolyed.

Measurement of serum phosphate levels using a mobile sensor

The measurement of serum phosphate concentration is crucial for patients with advanced chronic kidney disease (CKD) and those on maintenance dialysis, as abnormal phosphate levels may be associated with severe health risks. It is important to monitor serum phosphate levels on a regular basis in these patients; however, such measurements are generally limited to every 0.5-3 months, depending on the severity of CKD. This is due to the fact that serum phosphate measurements can only be performed at regular clinic visits, in addition to cost considerations. Here we present a portable and cost-effective point-of-care device capable of measuring serum phosphate levels using a single drop of blood (<60 μl). This is achieved by integrating a paper-based microfluidic platform with a custom-designed smartphone reader. This mobile sensor was tested on patients undergoing dialysis, where whole blood samples were acquired before starting the hemodialysis and during the three-hour treatment. This sampling during the hemodialysis, under patient consent, allowed us to test blood samples with a wide range of phosphate concentrations, and our results showed a strong correlation with the ground truth laboratory tests performed on the same patient samples (Pearson coefficient r = 0.95 and p < 0.001). Our 3D-printed smartphone attachment weighs about 400 g and costs less than 80 USD, whereas the material cost for the disposable test is <3.5 USD (under low volume manufacturing). This low-cost and easy-to-operate system can be used to measure serum phosphate levels at the point-of-care in about 45 min and can potentially be used on a daily basis by patients at home.

Application of smartphone-based spectroscopy to biosample analysis: A review

The emergence of the smartphones has brought extensive changes to our lifestyles, from communicating with one another, to shopping and enjoyment of entertainment, and from studying to functioning at the workplace (and in the field). At the same time, this portable device has also provided new possibilities in scientific research and applications. Based on the growing awareness of good health management, researchers have coupled health monitoring to smartphone sensing technologies. Along the way, there have been developed a variety of smartphone-based optical detection platforms for analyzing biological samples, including standalone smartphone units and integrated smartphone sensing systems. In this review, we outline the applications of smartphone-based optical sensors for biosamples. These applications focus mainly on three aspects: Microscopic imaging sensing, colorimetric sensing and luminescence sensing. We also discuss briefly some limitations of the current state of smartphone-based spectroscopy and present prospects of the future applicability of smartphone sensors.

Electrochemical Detection and Point-of-Care Testing for Circulating Tumor Cells: Current Techniques and Future Potentials

Circulating tumor cells (CTCs) are tumor cells that escaped from the primary tumor or the metastasis into the blood and they play a major role in the initiation of metastasis and tumor recurrence. Thus, it is widely accepted that CTC is the main target of liquid biopsy. In the past few decades, the separation of CTC based on the electrochemical method has attracted widespread attention due to its convenience, rapidness, low cost, high sensitivity, and no need for complex instruments and equipment. At present, CTC detection is not widely used in the clinic due to various reasons. Point-of-care CTC detection provides us with a possibility, which is sensitive, fast, cheap, and easy to operate. More importantly, the testing instrument is small and portable, and the testing does not require specialized laboratories and specialized clinical examiners. In this review, we summarized the latest developments in the electrochemical-based CTC detection and point-of-care CTC detection, and discussed the challenges and possible trends.

A new analytical platform for potential point-of-care testing of circulating tumor cells

It is of significance to detect circulating tumor cells (CTCs) in whole blood using transportable instruments at the point of care to assist evaluating chemotherapeutic efficacy and recurrence risk of cancer patients. However, the current widely used detection methods either require expensive and complex equipments, need complicated enrichment steps, or produce high rates of false positive and/or negative results. Aiming for solving the two critical challenges involved in instrumentation miniaturization and simplification of sample preparation for POCT of CTCs without sacrificing the detection sensitivity and accuracy, this work reports a custom-built, automatic, large field-of-view microscopic CTC cytometer and a novel enrichment strategy based on a synthesized peptide ligand discovered from One-Bead One-Compound library screening. The custom-built microscope has compact size, low weight and efficient cost while still maintaining a detection limit of as low as 5 target objects. The simplified sample preparation utilized a novel peptide LXW7 functionalized to magnetic beads and allows for rapid, highly selective and sensitive detection of CTCs. This analytical platform may fulfill the unmet need for possible point-of-care CTC counting, and provide a new option for early diagnosis of cancers and convenient evaluation of chemotherapeutic efficacy and cancer recurrence.

Diagnostic methods and potential portable biosensors for coronavirus disease 2019

Timely detection and diagnosis are urgently needed to guide epidemiological measures, infection control, antiviral treatment, and vaccine research. In this review, biomarkers/indicators for diagnosis of coronavirus disease 2019 (COVID-19) or detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the environment are summarized and discussed. It is concluded that the detection methods targeting antibodies are not suitable for screening of early and asymptomatic cases since most patients had an antibody response at about 10 days after onset of symptoms. However, antibody detection methods can be combined with quantitative real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) to significantly improve the sensitivity and specificity of diagnosis, and boost vaccine research. Fast, sensitive and accurate detection methods targeting antigens need to be developed urgently. Various specimens for diagnosis or detection are compared and analyzed. Among them, deep throat saliva and induced sputum are desired for RT-qPCR test or other early detection technologies. Chest computerized tomography (CT) scan, RT-qPCR, lateral flow immunochromatographic strip (LFICS) for diagnosis of COVID-19 are summarized and compared. Specially, potential electrochemical (EC) biosensor, surface enhanced Raman scattering (SERS)-based biosensor, field-effect transistor (FET)-based biosensor, surface plasmon resonance (SPR)-based biosensor and artificial intelligence (AI) assisted diagnosis of COVID-19 are emphasized. Finally, some commercialized portable detection device, current challenges and future directions are discussed.

Nanomaterial-based immunosensors for ultrasensitive detection of pesticides/herbicides: Current status and perspectives

The increasing level of pesticides and herbicides in food and water sources is a growing threat to human health and the environment. The development of portable, sensitive, specific, simple, and cost-effective sensors is hence in high demand to avoid exposure or consumption of these chemicals through efficient monitoring of their levels in food as well as water samples. The use of nanomaterials (NMs) for the construction of an immunosensing system was demonstrated to be an efficient and effective option to realize selective sensing against pesticides/herbicides. The potential of such applications has hence been demonstrated for a variety of NMs including graphene, carbon nanotubes (CNTs), metal nanoparticles, and nano-polymers either in pristine or composite forms based on diverse sensing principles (e.g., electrochemical, optical, and quartz crystal microbalance (QCM)). This article evaluates the development, applicability, and performances of NM-based immunosensors for the measurement of pesticides and herbicides in water, food, and soil samples. The performance of all the surveyed sensors has been evaluated on the basis of key parameters, e.g., detection limit (DL), sensing range, and response time.

Blood glucose fluctuations detected by continuous glucose monitoring system in gout patients with normal glucose tolerance and the effect of urate-lowering therapy

AIM

The aim of this study was to investigate whether there are blood glucose fluctuations in gout patients with hyperuricemia and normal glucose tolerance, and the effect of urate-lowering therapy on blood glucose fluctuations.

METHODS

Thirty patients with newly diagnosed gout, hyperuricemia and normal glucose tolerance were enrolled in our study. Continuous glucose monitoring system (CGMS) was used to detect the blood glucose fluctuations of these gout patients. Changes in blood glucose fluctuations after allopurinol therapy were also evaluated.

RESULTS

Compared with the reference values of blood glucose fluctuation parameters in China, gout patients had greater glycemic fluctuations including higher mean amplitude of glucose excursions (MAGE) (4.65 vs 1.94 mmol/L, P < .001), higher largest amplitude of blood glucose excursions (LAGE) (4.99 vs 3.72 mmol/L, P < .001) and higher standard deviations of blood glucose (SDBG) (1.36 vs 0.79 mmol/L, P < .001). MAGE was significantly correlated with uric acid (β = .007, P = .024) and HOMA-insulin resistance (IR) (β = .508, P = .03). Allopurinol treatment significantly reduced MAGE (4.16 vs 4.65 mmol/L, P < .001), SDBG (0.99 vs 1.36 mmol/L, P < .001) and HOMA-IR (2.26 vs 3.01, P < .001) in gout patients.

CONCLUSION

Blood glucose fluctuation increased even in the stage of normal glucose tolerance among gout patients. Blood glucose fluctuations in gout patients were associated with the level of serum uric acid and allopurinol could decrease blood glucose fluctuation as well as IR.

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.

Smartphone-Based Electrochemical Potentiostat Detection System Using PEDOT: PSS/Chitosan/Graphene Modified Screen-Printed Electrodes for Dopamine Detection

In this work, a smartphone-based electrochemical detection system was designed and developed for rapid and real-time detection of dopamine (DA). The system included a screen-printed electrode (SPE) used as a sensor, a hand-held electrochemical potentiostat and a smart phone with a specially designed app. During the detection period, the SPEs modified with poly(3,4-ethylenedioxythiophene) (PEDOT), chitosan (CS) and graphene (G) were used to convert and amplify the electrochemical reaction signals. The electrochemical potentiostat was used to generate excitation electrical signals and collect the electrical signals converted from the sensor. The smartphone—connected to the detector via Bluetooth-was used to control the detector for tests, further process the uploaded data, and plot graphs in real time. Experimental results showed that the self-designed sensing system could be employed for highly selective detection of DA in the presence of interfering substances such as ascorbic acid (AA) and uric acid (UA). CV was carried out to characterize the electrochemical properties of the modified SPEs and the electrochemical behaviors of DA on the modified SPEs. Finally, according to the analysis of DPV responses of DA, the system could detect DA with a detection sensitivity of 0.52 ± 0.01 μA/μM and a limit of detection of 0.29 μM in the linear range of DA concentrations from 0.05 to 70 μM.

The Role and Challenges of Body Channel Communication in Wearable Flexible Electronics

Flexible electronics are compatible with film substrates that are soft and stretchable, resulting in conformal integration with human body. Integrated with various sensors and communication ICs, wearable flexible electronics are able to effectively track human vital signs without affecting the body activities. Such a wearable flexible system contains a sensor, a front-end amplifier (FEA), an analog-to-digital converter (ADC), a micro-controller unit (MCU), a radio, a power management unit (PMU), where the radio is the design bottleneck due to its high power consumption. Different from conventional wireless communications, body channel communication (BCC) uses the human body surface as the signal transmission medium resulting in less signal loss and low power consumption. However, there are some design challenges in BCC, including body channel model, backward loss, variable contact impedance, stringent spectral mask, crystalless design, body antenna effect, etc. In this paper, we conduct a survey on BCC transceiver, and analyze its potential role and challenges in wearable flexible electronics.

A smartphone-based biomedical sensory system

Disease diagnostics, food safety monitoring and environmental quality monitoring are the key means to safeguard human health. However, conventional detection devices for health care are costly, bulky and complex, restricting their applications in resource-limited areas of the world. With the rapid development of biosensors and the popularization of smartphones, smartphone-based sensing systems have emerged as novel detection devices that combine the sensitivity of biosensors and diverse functions of smartphones to provide a rapid, low-cost and convenient detection method. In these systems, a smartphone is used as a microscope to observe and count cells, as a camera to record fluorescence images, as an analytical platform to analyze experimental data, and as an effective tool to connect detection devices and online doctors. These systems are widely used for cell analysis, biochemical analysis, immunoassays, and molecular diagnosis, which are applied in the fields of disease diagnostics, food safety monitoring and environmental quality monitoring. Therefore, we discuss four types of smartphone-based sensing systems in this review paper, specifically in terms of the structure, performance and efficiency of these systems. Finally, we give some suggestions for improvement and future prospective trends.

Biosensors for Personal Mobile Health: A System Architecture Perspective

Advances in mobile biosensors, integrating developments in materials science and instrumentation, are fueling an expansion in health data being collected and analyzed in decentralized settings. For example, semiconductor-based sensors are enabling measurement of vital signs, and microfluidic-based sensors are enabling measurement of biochemical markers. As biosensors for mobile health are becoming increasingly paired with smart devices, it will become critical for researchers to design biosensors - with appropriate functionalities and specifications - to work seamlessly with accompanying connected hardware and software. This article describes recent research in biosensors, as well as current mobile health devices in use, as classified into four distinct system architectures that take into account the biosensing and data processing functions required in personal mobile health devices. We also discuss the path forward for integrating biosensors into smartphone-based mobile health devices.

The review of Lab-on-PCB for biomedical application

Prevention of infectious diseases, diagnosis of diseases, and determination of treatment options all rely on biosensors to detect and analyze biomarkers, which are usually divided into four parts: cell analysis, biochemical analysis, immunoassay, and molecular diagnosis. However, traditional biosensing devices are expensive, bulky, and require a lot of time to detect, which also limited its application in resource-limited areas. In recent years, Lab-on-PCB, which combines biosensing technology and PCB technology, has been widely used in biomedical applications due to its high integration, personalized design, and easy mass production. Among these Lab-on-PCB sensing devices, the PCB circuit plays an important role. It can be directly used as a resistance sensor to count cells, and also used as a control device to automatically control the detection device. Flexible PCBs can be used to make wearable medical biosensors. In addition, due to the high degree of integration of the PCB circuit, Lab-on-PCB can perform multiple inspections on the same platform, which reduces the inspection time equivalently. Therefore, in this review paper, we discuss the application of Lab-on-PCB in four analysis methods of cell analysis, biochemical analysis, immunoassay, and molecular diagnosis, and give some suggestions for improvement and future development trends at the end.

Recognition of big data mixed Raman spectra based on deep learning with smartphone as Raman analyzer

Raman spectral detection has emerged as a powerful analytical technique due to the advantages of fast acquisition, non-invasion, and low cost. The on-site application is highly dependent on Raman automatic analysis algorithm. However, current Raman algorithm research mainly focuses on small sample Raman spectroscopy (RS) identification with defects of low accuracy and detection rate. It is also difficult to realize rapid RS measurement under big data. In this paper, rapid recognition of mixtures in complex environments was realized by establishing a fast Raman analysis model based on deep learning through data training, self-learning, and parameter optimization. The cloud network architecture was proposed to apply deep learning to real-time detection using Smartphone-based Raman devices. This research solves the technical problems about mixture recognition under big data and thus could be used as a new method for fast and field RS detection in complex environments.

Frequency Modulated Parametric Oscillation for Antenna Powered Wireless Transmission of Voltage Sensing Signals

Wireless transmission of voltage signals are particularly useful for sensors embedded inside a closed environment where long-term operation without internal batteries is desirable. For this purpose, voltage tuning resonators can be used, because their voltage-dependent frequency responses can be contactlessly characterized by loop antennas connected to the output and input ports of a network analyzer. However, such passive sensors have limited remote detectability and temporal resolution, especially for smaller frequency shifts that would require repetitive averaging for acceptable measurement accuracy. To overcome these limitations, a double frequency parametric resonator is inductively coupled with a voltage tuning resonator to convert resonance frequency shifts of the passive sensor into frequency encoded oscillation signals that can be instantaneously detected over larger distance separations. This antenna powered FM transmitter has a compact design to achieve good voltage sensitivity and linearity, making it potentially useful for multiple applications from PH sensing to electrophysiological recording.

Smartphone-integrated urinary CTX-II immunosensor based on wavelength filtering from chromogenic reaction

The integration of smart IT devices and biochemical assays with optical biosensing technology facilitates the development of efficacious optical biosensors for many practical diagnostic fields, owing to their minimized use of high-technical electronic components and simple operation. Herein, we introduced a simple optical biosensing system based on the specific wavelength filtering principle and count-based analysis method. The developed system uses a smartphone with a paper-based signal guide and a biosensing channel. The paper-based signal guide was prepared by printing red patterns of various brightness on a black background. Given that a blue product is generated as a result of horseradish peroxidase (HRP)-based enzymatic reaction in the biosensing channel, the channel could be used as a blue filter that absorbs red light. When red light reflected from the red pattern is absorbed by the channel, the pattern appears black. As such, the color of the patterns is assimilated with the black background, so it seems to disappear. Consequently, the amount of blue product relative to the concentration of the target analyte can be measured by counting the number of observed patterns on the paper-based signal guide. In this study, the concentration of urinary C-telopeptide fragment of type II collagen (uCTX-II, 0-10 ng/mL) was measured using the developed system without complicated equipment. In addition, the quantitative analysis of uCTX-II in the real urine sample was successfully performed. Therefore, we expect that the developed optical transducing system could be practically used for point-of-care testing (POCT) diagnosis under resource-limited environmental conditions.

Fluorescent Double-Stranded DNA-Templated Copper Nanoprobes for Rapid Diagnosis of Tuberculosis

In this work, we investigate highly sensitive fluorescent Cu nanoparticles for use as rapid and specific nucleic acid amplification nanoprobes (NPs) for the diagnosis of tuberculosis. After applying polymerase chain reaction (PCR) to a tuberculosis (TB) sample, we demonstrate that the presence of the targeted IS6110 DNA sequence of TB can be easily and directly detected through the in situ formation of DNA-templated fluorescent Cu NPs and subsequently quantified using only a smartphone. Compared to traditional DNA analysis, this sensing platform does not require purification steps and eliminates the need for electrophoresis to confirm the PCR results. After optimization, this dsDNA-Cu NP-PCR method has the ability to analyze clinical TB nucleic acid samples at a detection limit of 5 fg/μL, and the fluorescent signal can be distinguished in only ∼3 min after the DNA has been amplified. Moreover, with the combination of smartphone-assisted imaging analysis, we can further reduce the instrument size/cost and enhance the portability. In this manner, we are able to eliminate the need for a fluorescent spectrophotometer to measure the clinical sample. These results demonstrate this platform's practical applicability, combining a smartphone and on-site analysis while retaining the detection performance, making it suitable for clinical DNA applications in resource-limited regions of the world.

IoT-Enabled Dual-Arm Motion Capture and Mapping for Telerobotics in Home Care

With the paradigm shift from hospital-centric healthcare to home-centric healthcare in Healthcare 4.0, healthcare robotics has become one of the fastest growing fields of robotics. The combination of robot capabilities with human intelligence, for example, telerobotics for home care, is gradually showing promising potentials. In this paper, the Home-TeleBot system, a generalized IoT-enabled telerobotic architecture designed to support home-centric healthcare system, is proposed. In particular, the implementation of it is realized by integrating human-motion-capture subsystem with robot-control subsystem. The dual-arm cooperative robot, YuMi, imitates human motion captured by a set of wearable inertial motion capture devices to complete tasks. The proposed approach using workspace mapping and path planning of robot manipulators, facilitates telerobot to execute tasks in a natural and human-like way. Based on the constant of proportionality calculated by comparing the human original workspace with the robot original workspace, the workspace mapping is achieved by making assumptions of the distance between end-effectors (human hands, robot's grippers) and shoulders. Additionally, robot manipulators' path is planned by setting virtual obstacles to constrain robot motion, which aims to improve the performance of robot's human-like motion. As a specific example of application, we apply the proposed architecture to a fetching task based on dual-arm motion capture and mapping for telerobotics in home care.

Palm-Sized Uric Acid Test Lab Powered by Smartphone for Proactive Gout Management

A simple and convenient photochemical system based on a smartphone-powered photochemical dongle and disposable photochemical test strips was proposed in this paper. The components of the system were only connected with each other in a simple hot-plug way, but provided a convenient function of biological sample detection. The photochemical dongle working as a highly rigorous reflectance spectral analyzer was used to evaluate the uric acid levels of the fingertip whole blood with the participation of the photochemical test strip for the point of care, which showed good agreement (linear regression coefficient of 0.99338) as compared to the results from the specific and bulky biochemical analyzer in the clinical test. Furthermore, combined with the widespread smartphone and well-developed Internet, the photochemical dongle could provide a flexible and portable platform for the evaluation and treatment of chronic diseases, such as gout, and it is promising to be applied in the remote chronic disease management.