Point-of-care Devices Research Articles

Magnetic Particle Spectroscopy for Point-of-Care: A Review on Recent Advances.

Since its first report in 2006, magnetic particle spectroscopy (MPS)-based biosensors have flourished over the past decade. Currently, MPS are used for a wide range of applications, such as disease diagnosis, foodborne pathogen detection, etc. In this work, different MPS platforms, such as dual-frequency and mono-frequency driving field designs, were reviewed. MPS combined with multi-functional magnetic nanoparticles (MNPs) have been extensively reported as a versatile platform for the detection of a long list of biomarkers. The surface-functionalized MNPs serve as nanoprobes that specifically bind and label target analytes from liquid samples. Herein, an analysis of the theories and mechanisms that underlie different MPS platforms, which enable the implementation of bioassays based on either volume or surface, was carried out. Furthermore, this review draws attention to some significant MPS platform applications in the biomedical and biological fields. In recent years, different kinds of MPS point-of-care (POC) devices have been reported independently by several groups in the world. Due to the high detection sensitivity, simple assay procedures and low cost per run, the MPS POC devices are expected to become more widespread in the future. In addition, the growth of telemedicine and remote monitoring has created a greater demand for POC devices, as patients are able to receive health assessments and obtain results from the comfort of their own homes. At the end of this review, we comment on the opportunities and challenges for POC devices as well as MPS devices regarding the intensely growing demand for rapid, affordable, high-sensitivity and user-friendly devices.

Emerging Technologies of Three-Dimensional Printing and Mobile Health in COVID-19 Immunity and Regenerative Dentistry.

The ongoing coronavirus disease 2019 (COVID-19) pandemic highlights the importance of developing point-of-care (POC) antibody tests for monitoring the COVID-19 immune response upon viral infection or following vaccination, which requires three key aspects to achieve optimal monitoring, including three-dimensional (3D)-printed POC devices, mobile health (mHealth), and noninvasive sampling. As a critical tissue engineering concept, additive manufacturing (AM, also known as 3D printing) enables accurate control over the dimensional and architectural features of the devices. mHealth refers to the use of portable digital devices, such as smartphones, tablet computers, and fitness and medical wearables, to support health, which facilitates contact tracing, and telehealth consultations during the pandemic. Compared with invasive biosample (blood), saliva is of great importance in the spread and surveillance of COVID-19 as a noninvasive diagnostic method for virus detection and immune status monitoring. However, investigations into 3D-printed POC antibody test and mHealth using noninvasive saliva are relatively limited. Further exploration of 3D-printed antibody POC tests and mHealth applications to monitor antibody production for either disease onset or immune response following vaccination is warranted. This review briefly describes the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus and immune response after infection and vaccination, then discusses current widely used binding antibody tests using blood samples and enzyme-linked immunosorbent assays on two-dimensional microplates before focusing upon emerging POC technological platforms, such as field-effect transistor biosensors, lateral flow assay, microfluidics, and AM for fabricating immunoassays, and the possibility of their combination with mHealth. This review proposes that noninvasive biofluid sampling combined with 3D POC antibody tests and mHealth technologies is a promising and novel approach for POC detection and surveillance of SARS-CoV-2 immune response. Furthermore, as key concepts in dentistry, the application of 3D printing and mHealth was also included to facilitate the appreciation of cutting edge techniques in regenerative dentistry. This review highlights the potential of 3D printing and mHealth in both COVID-19 immunity monitoring and regenerative dentistry.

High-frequency ultrasound point-of-care device to quantify myopia-induced microstructural changes in the anterior sclera.

To develop a point-of-care (POC) device using high-frequency ultrasound (US) for evaluating microstructural changes in the anterior sclera associated with myopia. The proposed POC device must satisfy four primary requirements for effective clinical use: the measurement component is handheld; the software must be simple and provide real-time feedback; patient safety and health data security requirements set forth by relevant governing bodies must be satisfied and the measurement data must have sufficient signal-to-noise ratio (SNR) and repeatability. Radiofrequency (RF) echo data acquired by the POC device will be processed using our quantitative US methods to characterise tissue microstructure and biomechanical properties. All stated requirements have been met in the developed POC device. The high-frequency transducer is housed in a custom, 3D-printed, pen-like holder that allows for easy measurements of the anterior sclera. Custom software provides a simple interface for data acquisition, real-time data display and secure data storage. Exposimetry measurements of the US pressure field indicate device compliance with United States Food and Drug Administration limits for ophthalmic US. In vivo measurements on a volunteer suggest the RF data SNR and acquisition consistency are suitable for quantitative analysis. A fully functioning POC device using high-frequency US has been created for evaluating the microstructure of the anterior sclera. Planned studies using the POC device to scan the eyes of myopia patients will help clarify how the anterior sclera microstructure may be affected by myopia. If effective, this portable, inexpensive and user-friendly system could be an important part of routine eye examinations.

Diagnostic Accuracy of Portable, Handheld Point-of-Care Tests vs Laboratory-Based Bilirubin Quantification in Neonates

Quantification of bilirubin in blood is essential for early diagnosis and timely treatment of neonatal hyperbilirubinemia. Handheld point-of-care (POC) devices may overcome the current issues with conventional laboratory-based bilirubin (LBB) quantification. To systematically evaluate the reported diagnostic accuracy of POC devices compared with LBB quantification. A systematic literature search was conducted in 6 electronic databases (Ovid MEDLINE, Embase, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, CINAHL, and Google Scholar) up to December 5, 2022. Studies were included in this systematic review and meta-analysis if they had a prospective cohort, retrospective cohort, or cross-sectional design and reported on the comparison between POC device(s) and LBB quantification in neonates aged 0 to 28 days. Point-of-care devices needed the following characteristics: portable, handheld, and able to provide a result within 30 minutes. This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline. Data extraction was performed by 2 independent reviewers into a prespecified, customized form. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Meta-analysis was performed of multiple Bland-Altman studies using the Tipton and Shuster method for the main outcome. The main outcome was mean difference and limits of agreement in bilirubin levels between POC device and LBB quantification. Secondary outcomes were (1) turnaround time (TAT), (2) blood volumes, and (3) percentage of failed quantifications. Ten studies met the inclusion criteria (9 cross-sectional studies and 1 prospective cohort study), representing 3122 neonates. Three studies were considered to have a high risk of bias. The Bilistick was evaluated as the index test in 8 studies and the BiliSpec in 2. A total of 3122 paired measurements showed a pooled mean difference in total bilirubin levels of -14 μmol/L, with pooled 95% CBs of -106 to 78 μmol/L. For the Bilistick, the pooled mean difference was -17 μmol/L (95% CBs, -114 to 80 μmol/L). Point-of-care devices were faster in returning results compared with LBB quantification, whereas blood volume needed was less. The Bilistick was more likely to have a failed quantification compared with LBB. Despite the advantages that handheld POC devices offer, these findings suggest that the imprecision for measurement of neonatal bilirubin needs improvement to tailor neonatal jaundice management.

A multistep immunoassay on a 3D-printed capillarity-driven microfluidic device for point-of-care diagnostics

Although efficient diagnostic testing often relies on centralized laboratories, rapid diagnostics at the point-of-care (POC) are increasingly investigated to provide an affordable and easy-to-use alternative that requires minimal external equipment. Implementing complex assays on such POC devices is challenging, and existing methods such as paper-based analytical devices suffer from laborious and heterogeneous fabrication. 3D printing is a promising technology to enable the single-step fabrication of such diagnostic devices. We previously reported monolithic, 3D-printed microfluidics driven by capillarity, and used the platform to implement a proof-of-concept enzyme-linked immunosorbent assay (ELISA) for immunoglobulin E (IgE) detection. In this study, we aimed to improve the time-to-result and detection limit of this approach by (i) designing a second-generation 3D-printed device and (ii) further optimizing the IgE ELISA. Herein, we selected horseradish peroxidase for faster and more sensitive signal amplification compared to the first-generation device, for which we adapted the microfluidic device design to allow sequential flow while using separated reagent channels for each assay step. To implement the ELISA on this new design, we decreased reagent volumes and incubation times to be compatible with POC, and then we translated this assay stepwise from microtiter plates to the completely 3D-printed, second-generation device. Overall, this work gives additional insight into the biocompatibility of these 3D-printed devices, as well as demonstrates the huge potential of powder bed 3D printing to fabricate POC diagnostic devices.

Magnetite-Based Biosensors and Molecular Logic Gates: From Magnetite Synthesis to Application

In the last few decades, point-of-care (POC) sensors have become increasingly important in the detection of various targets for the early diagnostics and treatment of diseases. Diverse nanomaterials are used as building blocks for the development of smart biosensors and magnetite nanoparticles (MNPs) are among them. The intrinsic properties of MNPs, such as their large surface area, chemical stability, ease of functionalization, high saturation magnetization, and more, mean they have great potential for use in biosensors. Moreover, the unique characteristics of MNPs, such as their response to external magnetic fields, allow them to be easily manipulated (concentrated and redispersed) in fluidic media. As they are functionalized with biomolecules, MNPs bear high sensitivity and selectivity towards the detection of target biomolecules, which means they are advantageous in biosensor development and lead to a more sensitive, rapid, and accurate identification and quantification of target analytes. Due to the abovementioned properties of functionalized MNPs and their unique magnetic characteristics, they could be employed in the creation of new POC devices, molecular logic gates, and new biomolecular-based biocomputing interfaces, which would build on new ideas and principles. The current review outlines the synthesis, surface coverage, and functionalization of MNPs, as well as recent advancements in magnetite-based biosensors for POC diagnostics and some perspectives in molecular logic, and it also contains some of our own results regarding the topic, which include synthetic MNPs, their application for sample preparation, and the design of fluorescent-based molecular logic gates.

Performances of Dried Blood Spots and Point-of-Care Devices to Identify Virological Failure in HIV-Infected Patients: A Systematic Review and Meta-Analysis

To broaden access to HIV viral load monitoring (VLM), the use of blood samples from dried blood spots (DBS) or point-of-care (POC) devices, could be of great help in settings where plasma is not easily accessible. The variety of assays available makes the choice complex. This systematic review and meta-analysis aims to estimate the sensitivity and specificity of DBS and POC devices to identify patients in virological failure using World Health Organization (WHO) recommendations (viral load ≥1000 copies/mL), compared with plasma, for the assays currently available. Four databases were searched for articles, and two reviewers independently identified articles reporting sensitivity and specificity of DBS and/or POC to identify patients in virological failure. We excluded articles that used other thresholds as well as articles with a total number of participants below 50 to avoid reporting bias. Heterogeneity and factors associated with assays' performances were assessed by I2 statistics and metaregression. The protocol of this review follows the PRISMA guidelines. Out of 941 articles, 47 were included: 32 DBS evaluations and 16 POC evaluations. Overall, when using DBS, the Abbott RT HIV-1, Roche CAP-CTM, NucliSENS BioMerieux and Aptima assays presented sensitivity and specificity exceeding 85%, but reported results were highly heterogeneous. Factors associated with better performances were high volume of blood and the use of the same assay for DBS and plasma VLM. Regarding the POC devices, SAMBA I, SAMBA II, and GeneXpert devices presented high sensitivity and specificity exceeding 90%, with less heterogeneity. DBS is suitable VLM, but performances can vary greatly depending on the protocols, and should be performed in trained centers. POC is suitable for VLM with less risk of heterogeneity but is more intensive in costs and logistics.

Cardiac troponin measurement at the point of care: educational recommendations on analytical and clinical aspects by the IFCC Committee on Clinical Applications of Cardiac Bio-Markers (IFCC C-CB).

The International Federation of Clinical Chemistry and Laboarator Medicine (IFCC) Committee on Clinical Applications of Cardiac Bio-Markers (C-CB) has provided evidence-based educational resources to aid and improve the understanding of important analytical and clinical aspects of cardiac biomarkers. The present IFCC C-CB educational report focuses on recommendations for appropriate use, analytical performance, and gaps in clinical studies related to the use of cardiac troponin (cTn) by point of care (POC) measurement, often referred to as a point of care testing (POCT). The use of high-sensitivity (hs)-cTn POC devices in accelerated diagnostic protocols used in emergency departments or outpatient clinics investigating acute coronary syndrome has the potential for improved efficacy, reduction of length of stay and reduced costs in the health care system. POCT workflow integration includes location of the instrument, assignment of collection and testing responsibility to (non-lab) staff, instrument maintenance, in-service and recurrent training, quality control, proficiency assessments, discrepant result trapping, and troubleshooting and inventory management.

Assessment of Urinary Biomarkers for Infectious Diseases Using Lateral Flow Assays: A Comprehensive Overview.

Screening of biomarkers is a powerful approach for providing a holistic view of the disease spectrum and facilitating the diagnosis and prognosis of the state of infectious diseases. Unaffected by the homeostasis mechanism in the human body, urine accommodates systemic changes and reflects the pathophysiological condition of an individual. Easy availability in large volumes and non-invasive sample collection have rendered urine an ideal source of biomarkers for various diseases. Infectious diseases may be communicable, and therefore early diagnosis and treatment are of immense importance. Current diagnostic approaches preclude the timely identification of clinical conditions and also lack portability. Point-of-care (POC) testing solutions have gained attention as alternative diagnostic measures due to their ability to provide rapid and on-site results. Lateral flow assays (LFAs) are the mainstay in POC device development and have attracted interest owing to their potential to provide instantaneous results in resource-limited settings. The discovery and optimization of a definitive biomarker can render POC testing an excellent platform, thus impacting unwarranted antibiotic administration and preventing the spread of infectious diseases. This Review summarizes the importance of urine as an emerging biological fluid in infectious disease research and diagnosis in clinical settings. We review the academic research related to LFAs. Further, we also describe commercial POC devices based on the identification of urinary biomarkers as diagnostic targets for infectious diseases. We also discuss the future use of LFAs in developing more effective POC tests for urinary biomarkers of various infections.

Comparison of Point-of-Care PT-INR by Hand-Held Device with Conventional PT-INR Testing in Anti-phospholipid Antibody Syndrome Patients on Oral Anticoagulation.

Evidence on agreement of point-of-care (POC) INR testing with laboratory testing in APS patients on oral anticoagulation (OAC), is scarce. This study assessed agreement of paired PT INR testing by a POC device vs. conventional platform-based laboratory test, in APS patients on OAC using a pre-determined definition of agreement. Simultaneous paired PT INR estimation in 92 APS patients was carried out, during October 2020-September 2021. POC INR was performed on capillary blood (pin prick) using the qLabs® PT-INR hand-held device, while laboratory INR estimation was performed using citrated blood (venepuncture) on STA-R Max Analyzer® using STA-NeoPTimal thromboplastin reagent®. Concordance was defined no greater than ± 30% (as per international standards ISO 17593:2007 guidelines) for each paired INR estimation. Agreement between the two was defined as ≥ 90% of paired INR measurements being concordant. 211 paired estimations were performed, within which 190 (90%) were concordant. Good correlation was seen between the 2 methods of INR estimation on Bland Altman plot analysis with an Intra-class correlation coefficient (95% CI) of 0.91(0.882, 0.932). Lab INR range > 4 (P = 0.001) was a significant predictor of higher variability between both methods of INR estimation. Lupus anti-coagulant, other anti-phospholipid antibodies (APL) or triple APL positivity did not result in any statistically significant variation in paired measurements. This study demonstrated good correlation between POC INR measurement and Lab INR estimation and agreement was ascertained between the 2 methods in APS patients on OAC.

Point-of-care device for Graves’ disease detection using Infrared Thermography

IR Thermography (IRT) provides real-time, non-invasive sub-surface images of the thyroid region without any hazardous radiation exposures. Thermography represents thermal radiation in the form of an image and provides information about important physiological parameters using skin temperature distribution. Graves' disease is the most frequently diagnosed disease of women in India. Patients with graves' disease have different temperature distribution relative to the healthy ones. This paper aims to use thermography with deep learning and machine learning techniques to develop a GUI/non-invasive method for detecting graves' disease. A CNN-based app is developed and deployed in a clinical environment to add to the analysis so as to diminish sparsity in the available data set. For our study IR Images of the sixty persons with different age groups and gender has been taken and showed that control and hyperthyroid patient have different behaviour and lie in different quadrants, which can help clinicians to conclude whether the patient is healthy or not. It is expected that this imaging biomarker test will reduce the ethical burden on clinicians' shoulders before recommending scintigraphy and standard thyroid blood tests, thus saving costs at patients' end and pathology labs in populated countries such as India. An affordable Thermal plug-and-play attachment can be connected to any smartphone for faster diagnosis at the patient end, converting the smartphone into a point of care device.

Photodegradation kinetics for bilirubin sensing: New solutions for old problems

Blood bilirubin levels monitoring is essential for the management of liver disease and neonatal hyperbilirubinemia. Whilst highly accurate, the existing bilirubin measurement techniques do not lend themselves to point-of-care (PoC) applications. To address this challenge, PoC devices using optical methods (mainly transcutaneous technique), have been demonstrated for bilirubin levels determination. Beyond its distinct absorption features used for optical measurements, bilirubin is known for its unique property of a non-catalytic degradation under blue light illumination. This is indeed the basis of blue light phototherapy used to treat or alleviate neonatal jaundice. This work investigates the feasibility of measuring bilirubin concentration using both multi-wavelength (MWL) and photodegradation kinetics approaches. Multi wavelength approach was investigated by correlating the optical responses with the concentration of bilirubin. The degradation approach was investigated by assessing the changes in bilirubin's spectrophotometric characteristics induced by blue light (470 nm) irradiation as a function of optical energy density (up to 3 J/cm2). The solid-state full-range spectroscopy (absorbance, reflectance, photoluminescence, and Raman) and a PoC testing on a system-on-chip are used and a new kinetic model describing the degradation reaction is proposed. Results show that the optical responses and photodegradation features correlated well with bilirubin concentration with R-square greater than 0.9. Additionally, the techniques' performance was examined using the merits of accuracy, precision, sensitivity, and specificity parameters (all are greater than 90%). Our analyses suggest that the method is sufficiently enough to provide reliable indications of bilirubin levels. The proposed technique may offer a portable, miniaturized, and facile mean for in-vitro and in-vivo bilirubin monitoring and estimation.

Emergence of infectious diseases and role of advanced nanomaterials in point-of-care diagnostics: a review

ABSTRACT Infectious outbreaks are the foremost global public health concern, challenging the current healthcare system, which claims millions of lives annually. The most crucial way to control an infectious outbreak is by early detection through point-of-care (POC) diagnostics. POC diagnostics are highly advantageous owing to the prompt diagnosis, which is economical, simple and highly efficient with remote access capabilities. In particular, utilization of nanomaterials to architect POC devices has enabled highly integrated and portable (compact) devices with enhanced efficiency. As such, this review will detail the factors influencing the emergence of infectious diseases and methods for fast and accurate detection, thus elucidating the underlying factors of these infections. Furthermore, it comprehensively highlights the importance of different nanomaterials in POCs to detect nucleic acid, whole pathogens, proteins and antibody detection systems. Finally, we summarize findings reported on nanomaterials based on advanced POCs such as lab-on-chip, lab-on-disc-devices, point-of-action and hospital-on-chip. To this end, we discuss the challenges, potential solutions, prospects of integrating internet-of-things, artificial intelligence, 5G communications and data clouding to achieve intelligent POCs.

Ultrasensitive colorimetric detection of fluoride and arsenate in water and mammalian cells using recyclable metal oxacalixarene probe: a lateral flow assay

Globally 3 billion people are consuming water with moderately high concentrations of fluoride and arsenic. The development of a simple point of care (PoC) device or home device for the detection of fluoride/arsenic ensures safety before consuming water. Till date, lateral flow assay (LFA) based PoC devices can detect nucleic acids, viruses and diseases. An aluminium complex of rhodamine B functionalized oxacalix[4]arene (L) was designed to execute the LFA-based PoC device. Initially, Al3+ and Fe3+ ions were involved in complexation with the rhodamine B functionalized oxacalix[4]arene (L), resulting C1 (L-Al3+) and C2 (L-Fe3+) complexes respectively. The receptor L, as well as the probes (C1, C2), were characterized thoroughly using mass spectroscopy, FTIR, NMR, and EA. C1 and C2 were further utilized as recyclable probes for the detection of aqueous fluoride (21 ppb) and arsenate (1.92 ppb) respectively. The computational calculation indicates that upon complexation, the spirolactam ring opening at the rhodamine B site leads to optoelectronic changes. The consistency of LFA-based portable sensing device has been tested with water samples, synthetic fluoride standards and dental care products like toothpaste and mouthwash with concentrations ≥ 3 ppm. Moreover, fixed cell imaging experiments were performed to ascertain the in-vitro sensing phenomena.

Advances in Electrochemical Nano-Biosensors for Biomedical and Environmental Applications: From Current Work to Future Perspectives.

Modern life quality is strongly supported by the advances made in biosensors, which has been attributed to their crucial and viable contribution in point-of-care (POC) technology developments. POC devices are exploited for the fast tracing of disease progression, rapid analysis of water, and food quality assessment. Blood glucose meters, home pregnancy strips, and COVID-19 rapid tests all represent common examples of successful biosensors. Biosensors can provide great specificity due to the incorporation of selective bio-recognition elements and portability at significantly reduced costs. Electrochemical biosensor platforms are one of the most advantageous of these platforms because they offer many merits, such as being cheap, selective, specific, rapid, and portable. Furthermore, they can be incorporated into smartphones and various analytical approaches in order to increase their sensitivity and many other properties. As a very broad and interdisciplinary area of research and development, biosensors include all disciplines and backgrounds from materials science, chemistry, physics, medicine, microbiology/biology, and engineering. Accordingly, in this state-of-the-art article, historical background alongside the long journey of biosensing construction and development, starting from the Clark oxygen electrode until reaching highly advanced wearable stretchable biosensing devices, are discussed. Consequently, selected examples among the miscellaneous applications of nanobiosensors (such as microbial detection, cancer diagnosis, toxicity analysis, food quality-control assurance, point of care, and health prognosis) are described. Eventually, future perspectives for intelligent biosensor commercialization and exploitation in real-life that is going to be supported by machine learning and artificial intelligence (AI) are stated.

Plasmonic/magnetic nanoarchitectures: From controllable design to biosensing and bioelectronic interfaces

Controllable design of the nanocrystal-assembled plasmonic/magnetic nanoarchitectures (P/MNAs) inspires abundant methodologies to enhance light-matter interactions and control magnetic-induced effects by means of fine-tuning the morphology and ordered packing of noble metallic or magnetic building blocks. The burgeoning development of multifunctional nanoarchitectures has opened up broad range of interdisciplinary applications including biosensing, in vitro diagnostic devices, point-of-care (POC) platforms, and soft bioelectronics. By taking advantage of their customizability and efficient conjugation with capping biomolecules, various nanoarchitectures have been integrated into high-performance biosensors with remarkable sensitivity and versatility, enabling key features that combined multiplexed detection, ease-of-use and miniaturization. In this review, we provide an overview of the representative developments of nanoarchitectures that being built by plasmonic and magnetic nanoparticles over recent decades. The design principles and key mechanisms for signal amplification and quantitative sensitivity have been explored. We highlight the structure-function programmability and prospects of addressing the main limitations for conventional biosensing strategies in terms of accurate selectivity, sensitivity, throughput, and optoelectronic integration. State-of-the-art strategies to achieve affordable and field-deployable POC devices for early multiplexed detection of infectious diseases such as COVID-19 has been covered in this review. Finally, we discuss the urgent yet challenging issues in nanoarchitectures design and related biosensing application, such as large-scale fabrication and integration with portable devices, and provide perspectives and suggestions on developing smart biosensors that connecting the materials science and biomedical engineering for personal health monitoring.

Printed graphene-based electrochemical sensor with integrated paper microfluidics for rapid lidocaine detection in blood

Topical lidocaine patches are commonly used to relieve pain and suffering in various clinical and household settings. Despite its extensive use, excessive skin absorption during numbing or pain reduction procedures can cause systemic toxicity, which can lead to life-threatening conditions. Rapid and reliable monitoring of escalating levels of lidocaine in the blood could help management/prevention of lidocaine overdose and its associated complications. To address this need, here we have developed a disposable point-of-care (POC) diagnostic platform composed of an integrated graphene-based electrochemical sensor with paper-based microfluidics for rapid detection of lidocaine levels in serum and blood samples. The fabrication process takes advantage of advanced, scalable manufacturing techniques, including printing, laser processing, and nondestructive near infrared (NIR) drying. The sensitivity tests of the platform revealed a sensitivity of ∼0.2 μA μM−1 towards lidocaine concentrations in the clinically relevant range (1–100 μM) in both complex matrix fluids of serum and blood with high cross specificity in the presence of the interfering analytes. This proof-of-concept platform could be regarded as the first step toward the development of low-cost and translational POC devices that could help in better pain management and reduce potential side effects or misuse of analgesics.

Pullulan-stabilized gold nanoparticles tablet as a nanozyme sensor for point-of-care applications

In this article, we first report the fabrication of pullulan-stabilized gold nanoparticles tablet (AuNPs-pTab) as a point-of-care (POC) analytical device using pullulan-AuNPs solution (AuNPs-pSol) without any additional tablet forming ingredient and then use AuNPs-pTab as a colorimetric sensor for glucose detection in human saliva samples. The AuNPs-pTab sensor fabrication comprises three steps: 1) synthesis of AuNPs-pSol, 2) formation of AuNPs-pTab in an oven at 50 °C for 30 min, and 3) colorimetric detection of glucose using AuNPs-pTab as peroxidase-mimic enzymatic activity employing TMB-H2O2 system. AuNPs-pSol was synthesized by one-pot two-steps method using gold (III) chloride and pullulan as an all-in-one reagent; reducing/stabilizing/tablet forming agent followed by casting of AuNPs-pTab. The fabricated tablet was characterized using UV–vis, FTIR, TEM, DLS, and zeta potential analysis, and results were compared with AuNPs-pSol. The morphology of nanoparticles in tablet was similar to the AuNPs in solution phase. The AuNPs-pTab is stable for >6 months as compared to AuNPs-pSol which lost stability after one month. The peroxidase-mimic enzymatic behavior of AuNPs-pTab was 25% better than AuNPs-pSol as depicted by the development of intense blue color of oxidized TMB. The effect of pH, temperature, and concentration of TMB as well as AuNPs-pTab was studied to see their impact on glucose assay. The reaction rate was calculated using Michaelis Menten's model of TMB oxidation while the calibration curve for glucose monitoring is fitted using a dose-response equation with a linear range of 0–5 μM of glucose. The limit of detection (LoD) for H2O2 was found to be 28.7 μM in the buffer while it was 38.2 and 163.04 μM for glucose in buffer and artificial human saliva, respectively. Percentage recovery for real human saliva was calculated as 93.6–107.7%. Our newly proposed AuNPs-pTab sensor has shown excellent peroxidase-like activity and provides an easy substitute for AuNPs solution with enhanced catalytic efficiency. Moreover, the AuNPs-pTab sensor is a promising platform for POC devices due to its fulfillment of ASSURED criteria. AuNPs-pTab sensor opens a new horizon in disease diagnosis due to its ability to detect H2O2 which is a potential biomarker for many diseases. Our work is appealing to researchers working in nanotechnology, and the development of new bioassays as well as POC devices.

A Review of Commercially Available Point-of-Care Devices to Concentrate Platelet-Rich Plasma.

Platelet-rich plasma (PRP) is a promising therapy treatment option for multiple orthopedic conditions, which has demonstrated expanding clinical use. With increased clinical use of PRP, there has been a greater demand for point-of-care (POC) biologic devices. For this review, publicly available information provided by the device corporations, PubMed, Medline, and Embase databases were searched for studies related to POC device function. A scoping review study design was selected to explore the breadth of knowledge in the literature regarding PRP POC devices. ProofPoint Biologics demonstrated the highest laboratory platelet increase (5.2 ± 0.28-fold) and the longest processing time (49 ± 1.4 minutes). Celling demonstrated the lowest laboratory platelet increase (2.7 ± 0.8-fold), while AcCELLerated had the fastest processing time (18 ± 1.4 minutes for PurePRP® AB60 Pure (Pure Accelerated Biologics, Tequesta, FL) and 13.5 ± 2.1 minutes for AbsolutePRP® (Emcyte Corporation, Fort Myers, FL)). Celling had the lowest cost out of the various biologic devices. There is significant variability in the technical features, cost, processing time, and centrifugation parameters of the different commercially available point-of-care devices.

Efficient Point-of-Care Detection of Uric Acid in the Human Blood Sample with an Enhanced Electrocatalytic Response Using Nanocomposites of Cobalt and Mixed-Valent Molybdenum Sulfide.

This work efficiently detects uric acid (UA) in a human blood sample using cobalt nanoparticle-immobilized mixed-valent molybdenum sulfide on the copper substrate in a point-of-care (PoC) device. The sensor electrode was fabricated by micromachining of Cu clad boards employing an engraver to generate a three-electrode system consisting of working electrode (WE), reference electrode (RE), and counter electrode (CE). The WE was subjected to physical vapor deposition of mixed-valent MoSx layers by a reaction between Mo(CO)6 and H2S at ∼200 °C using a simple setup following which CoNPs were electrochemically deposited. The RE and CE were covered with Ag/AgCl and Ag paste, respectively. A plasma separation membrane acted as the medium of UA/blood serum delivery to the electrodes. The material and electrochemical characterization confirmed that CoNPs over MoSx provided an enlarged electroactive surface for the direct electron transfer to achieve an enhanced electrocatalytic response. The binary combination of CoNPs and MoSx layers over the Cu electrode reduced the charge-transfer resistance by two times, enhanced the surface adsorption by more than two times, and yielded a high diffusion coefficient of 3.46 × 10-3 cm2/s. These interfacial effects facilitated the UA oxidation, leading to unprecedented mA range current density for UA sensing for the PoC device. The electrochemical detection tests in the PoC device revealed a sensitivity of 64.7 μA/μM cm-2, which is ∼50 times higher compared to the latest reported value (1.23 μA/μM cm-2), a high limit of detection of 5 nM, and shelf life of 6 months, confirming the synergistic effect-mediated high sensitivity under PoC settings. Interference tests confirmed no intervention of similar analytes. Tests on blood samples demonstrated a recovery percentage close to 100% in human serum UA, signifying the suitability of the nanocomposite-based sensor and the PoC device for clinical sensing applications.