Nucleic acid based point-of-care diagnostic technology for infectious disease detection using machine learning empowered smartphone-interfaced quantitative colorimetry.

We report a nucleic acid-based point of care testing technology for infectious disease detection at resource limited settings by integrating a low-cost portable device with machine learning-empowered quantitative colorimetric analytics that can be interfaced via a smartphone application. We substantiate our proposition by demonstrating the efficacy of this technology in detecting COVID-19 infection from human swab samples, using the RT-LAMP protocol. Comparison with gold standard results from real-time PCR evidences high sensitivity and specificity, ensuring simplicity, portability, and user-friendliness of the technology at the same time.

Instrument-free single-step direct estimation of the plasma glucose level from one drop of blood using smartphone-interfaced analytics on a paper strip.

We demonstrated an instrument-free miniaturized adaptation of the laboratory gold standard methodology for the direct estimation of plasma glucose from a drop of whole blood using a low-cost single-user-step paper-strip sensor interfaced with a smartphone. Unlike a majority of the existing glucose meters that use whole blood-based indirect sensing technologies, our direct adaptation of the gold-standard laboratory benchmark could eliminate the possibilities of cross interference with other analytes present in the whole blood by facilitating an plasma separation, capillary flow and colorimetric reaction occurring concomitantly, without incurring additional device complexity or embodiment. The test reagents were dispensed in lyophilized form, and the resulting paper strips were found to be stable over three months stored in a normal freezer, rendering easy adaptability commensurate with the constrained supply chains in extreme resource-poor settings.

Piecewise Isothermal Nucleic Acid Testing (PINAT) for Infectious Disease Detection with Sample-to-Result Integration at the Point-of-Care.

We developed a piecewise isothermal nucleic acid test (PINAT) as a platform technology for diagnosing pathogen-associated infections, empowered by an illustrative novel methodology that embeds an exclusive DNA-mediated specific probing reaction with the backbone of an isothermal reverse transcription cum amplification protocol for detecting viral RNA. In a point-of-care format, this test is executable in a unified single-step, single-chamber procedure, leading to seamless sample-to-result integration in an inexpensive, scalable, pre-programmable, and customizable portable device, with mobile-app-integrated interpretation and analytics involving minimal manually operative procedures. The test exhibited a high sensitivity and specificity of detection when assessed using 200 double-blind patient samples for detecting SARS-CoV-2 infection by the Indian Council of Medical Research (ICMR), and subsequently using 170 double-blind patient samples in a point-of-care format outside controlled laboratory settings as performed by unskilled technicians in an organized clinical trial.

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.

Fabricating Paper Based Devices Using Correction Pens.

We present a rapid (<10 s), cost-effective, unique single-step method for fabricating paper-based devices without necessitating any expensive instrumentation, simply by deploying correction pens that are otherwise commonly used for masking typos in printed or written matters. The marked regions formed by deposits from the correction pen demonstrate ubiquitous flow resistances to typical aqueous solutions and organic solvents in the transverse direction, resulting in a preferential bulk flow along the axial direction of the paper channels 'fabricated' in the process. Considering the simplicity and cost-effectiveness of this platform, it is deemed to be ideal for (bio) chemical sensing and point-of-care diagnostics in resource-limited settings.

Highly efficient, selective, sensitive and stability indicating RP-HPLC-UV method for the quantitative determination of potential impurities and characterization of four novel impurities in eslicarbazepine acetate active pharmaceutical ingredient by LC/ESI-IT/MS/MS.

A novel, sensitive, selective and stability indicating LC-UV method was developed for the determination of potential impurities of eslicarbazepine acetate. High performance liquid chromatographic investigation of eslicarbazepine acetate laboratory sample revealed the presence of several impurities. Three impurities were characterized rapidly and four impurities were found to be unknown.