The ability to rapidly diagnose, track, and disseminate information for SARS-CoV-2 is critical to minimize its spread. Here, we engineered a portable smartphone-based quantum barcode serological ...assay device for real-time surveillance of patients infected with SARS-CoV-2. Our device achieved a clinical sensitivity of 90% and specificity of 100% for SARS-CoV-2, as compared to 34% and 100%, respectively, for lateral flow assays in a head-to-head comparison. The lateral flow assay misdiagnosed ∼2 out of 3 SARS-CoV-2 positive patients. Our quantum dot barcode device has ∼3 times greater clinical sensitivity because it is ∼140 times more analytically sensitive than lateral flow assays. Our device can diagnose SARS-CoV-2 at different sampling dates and infectious severity. We developed a databasing app to provide instantaneous results to inform patients, physicians, and public health agencies. This assay and device enable real-time surveillance of SARS-CoV-2 seroprevalence and potential immunity.
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IJS, KILJ, NUK, PNG, UL, UM
COVID-19 has spread globally since its discovery in Hubei province, China in December 2019. A combination of computed tomography imaging, whole genome sequencing, and electron microscopy were ...initially used to screen and identify SARS-CoV-2, the viral etiology of COVID-19. The aim of this review article is to inform the audience of diagnostic and surveillance technologies for SARS-CoV-2 and their performance characteristics. We describe point-of-care diagnostics that are on the horizon and encourage academics to advance their technologies beyond conception. Developing plug-and-play diagnostics to manage the SARS-CoV-2 outbreak would be useful in preventing future epidemics.
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Diagnostic assays are commonly performed in multiple steps, where reagents are added at specific times and concentrations into a reaction chamber. The reagents require storage, preparation, and ...addition in the correct sequence and amount. These steps rely on trained technicians and instrumentation to perform each task. The reliance on such resources hinders the use of these diagnostic assays by lay users. We developed a tablet that can sequentially introduce prequantified lyophilized diagnostic reagents at specific time points for a multistep assay. We designed the tablet to have multiple layers using cellulose-grade polymers, such as microcrystalline cellulose and hydroxypropyl cellulose. Our formulation allows each layer to dissolve at a controlled rate to introduce reagents into the solution sequentially. The release rate is controlled by modulating the compression force or chemical formulation of the layer. Controlling the reagent release time is important because different assays have specific times when reagents need to be added. As proof of concept, we demonstrated two different assays with our tablet system. Our tablet detected nucleic acid target (tpp47 gene from Treponema pallidum) and nitrite ions in an aqueous sample without user intervention. Our multilayer tablets can simplify multistep assay processes.
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Point-of-care diagnostic assays often involve multistep reactions, requiring a wide range of precise temperatures. Although precise heating is critical to performing these assays, it is challenging ...to provide it in an electricity-free format away from established infrastructure. Chemical heaters are electricity-free and use exothermic reactions. However, they are unsuitable for point-of-care multistep reactions because they sacrifice portability, have a narrow range of achievable temperatures, and long ramp-up times. Here we developed a miniature heater by modulating the lithium–water reaction kinetics using bubbles in a channel. Our heaters are up to 8,000 times smaller than current devices and can provide precise (within 5 °C) and tunable heating from 37 °C to 65 °C (ΔTRT = 12 °C to 40 °C) with ramp-up times of a minute. We demonstrate field portablity and stability and show their use in an electricity-free multistep workflow that needs a range of temperatures. Ultimately, we envision providing better access to cutting edge biochemical techniques, including diagnostics, by making portable and electricityfree heating available at any location.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
We describe the current difference in reporting the performance of nanotechnology diagnostic devices between technologists and clinicians. This perspective specifies the “metrics” used to evaluate ...these devices and describes strategies to bridge the gap between these two communities in order to accelerate the translation from academic bench to the clinic. We use two recently published ACS Nano articles to highlight the evaluation of silicon nanowire and surface-enhanced Raman spectroscopy-breath diagnostic tests for patients afflicted with cancer and asthma. These studies represent some of the earliest studies of emerging nanotechnology devices utilizing clinical parameters to assess performance.
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Simplifying Assays by Tableting Reagents Udugama, Buddhisha; Kadhiresan, Pranav; Samarakoon, Amila ...
Journal of the American Chemical Society,
12/2017, Volume:
139, Issue:
48
Journal Article
Peer reviewed
Medical diagnostic assays provide exquisite sensitivity and precision in the diagnoses of patients. However, these technologies often require multiple steps, skilled technicians, and facilities to ...store heat-sensitive reagents. Here, we developed a high-throughput compression method to incorporate different assay components into color-coded tablets. With our technique, premeasured quantities of reagents can be encapsulated in compressed tablets. We show that tableting stabilizes heat-sensitive reagents and simplifies a broad range of assays, including isothermal nucleic acid amplification techniques, enzyme-based immunoassays, and microbead diagnostics. To test the clinical readiness of this tableting technology, we show the ability of tableted diagnostics for screening hepatitis B-positive patient samples. Our development simplifies complicated assays and the transportation of reagents and mitigates the need for refrigeration of reagents. This advances the use of complex assays in remote areas with limited infrastructure.
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Diagnostics play an important role in the management of infectious diseases, from factoring in on the treatment of patients to responding to a worldwide pandemic. Point of care diagnostics are ...especially important to conduct diagnoses near patients to facilitate rapid responses. This allows for early detection, treatment, surveillance and containment of infectious diseases. In order to develop diagnostics that are amendable at the point of care, they need to be less reliant on expert training and infrastructure. The goal of my thesis was to develop equipment-free tools to improve the accessibility of diagnostic assays to the point of care, specifically in resource-limited settings. My thesis focuses on building a toolkit to help conduct assays outside of centralized labs. The first project focuses on developing a tablet to provide thermal stability to diagnostic reagents, allowing for transporting and storing reagents without the need for refrigeration. The second project focuses on building a multi-layered tablet to time-programmatically release reagents to conduct a diagnostic assay, minimizing the need for manual intervention and technical expertise. The last project focuses on building an electricity-free and portable heater to provide tunable and precise temperatures for conducting multi-step assays. Together, these tools can be used in the future to conduct diagnostic assays at any location, outside of centralized labs.
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