An IoT-enabled paper sensor platform for real-time analysis of isothermal nucleic acid amplification tests

Paper-based sensors can be exploited to develop low-cost, disposable, and rapid assays for the detection of a large variety of analytes. We report a paper-based sensor system for a point-of-care (POC) nucleic acid amplification test that can quantitatively detect multiple genes from different pathogens. The POC system combines a paper sensor chip and a portable instrument, which is built on an Internet of Things (IoT) platform. The paper-based sensor provides the functions of reagent storage, sample transportation, and nucleic acid amplification. The IoT instrument uses an Arduino microcontroller to control temperature, collect fluorescence images, and store the data in cloud storage via a WiFi network. A compact fluorescence reader was designed to measure fluorescence images of the amplicons during a loop-mediated isothermal amplification reaction in real-time. The real-time detection capability enables the quantitative analysis of target genes. The results show that the paper-based sensor cam distinguish multiple genes of the genomic DNA extracted from Escherichia coli and Campylobacter jejuni, with the concentration as low as 2 × 10³ copies/μL. The affordable instrument, in conjunction with the disposable paper sensor chip, would have a great potential for POC detections of pathogens.