A low-cost smartphone-based platform for highly sensitive point-of-care testing with persistent luminescent phosphors


Through their computational power and connectivity, smartphones are poised to rapidly expand telemedicine and transform healthcare by enabling better personal health monitoring and rapid diagnostics. Recently, a variety of platforms have been developed to enable smartphone-based point-of-care testing using imaging-based readout with the smartphone camera as the detector. Fluorescent reporters have been shown to improve the sensitivity of assays over colorimetric labels, but fluorescence readout necessitates incorporating optical hardware into the detection system, adding to the cost and complexity of the device. Here we present a simple, low-cost smartphone-based detection platform for highly sensitive luminescence imaging readout of point-of-care tests run with persistent luminescent phosphors as reporters. The extremely bright and long-lived emission of persistent phosphors allows sensitive analyte detection with a smartphone by a facile time-gated imaging strategy. Phosphors are first briefly excited with the phone's camera flash, followed by switching off the flash, and subsequent imaging of phosphor luminescence with the camera. Using this approach, we demonstrate detection of human chorionic gonadotropin using a lateral flow assay and the smartphone platform with strontium aluminate nanoparticles as reporters, giving a detection limit of ?45 pg mL?1 (1.2 pM) in buffer. Time-gated imaging on a smartphone can be readily adapted for sensitive and potentially quantitative testing using other point-of-care formats, and is workable with a variety of persistent luminescent materials.



persistent luminescence, phosphorescence, smartphone, diagnostics, nanoparticle, lateral flow assay, surface functionalization, time-gated detection, image analysis


Copyright 2017 Lab on a Chip. This is a post-print version of a published paper that is available at: https://europepmc.org/articles/pmc5476460. Recommended citation: Paterson, Andrew S., Balakrishnan Raja, Vinay Mandadi, Blane Townsend, Miles Lee, Alex Buell, Binh Vu, Jakoah Brgoch, and Richard C. Willson. "A low-cost smartphone-based platform for highly sensitive point-of-care testing with persistent luminescent phosphors." Lab on a Chip 17, no. 6 (2017): 1051-1059. DOI: 10.1039/c6lc01167e. This item has been deposited in accordance with publisher copyright and licensing terms and with the author's permission.