An internet of things-based intensity and time-resolved fluorescence reader for point-of-care testing

• Published in: Biosensors & bioelectronics Vol. 154; p. 112074
• Main Authors: Alonso, O., Franch, N., Canals, J., Arias-Alpízar, K., de la Serna, E., Baldrich, E., Diéguez, A.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15-04-2020
• Subjects: Decay time; Malaria diagnosis; Miniature fluorescent microscope; Rapid diagnostic test (RDT); Single board computer (SBC); SPADs detector; SPADs detector; Rapid diagnostic test (RDT); Malaria diagnosis; Single board computer (SBC); Decay time; Miniature fluorescent microscope
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2020.112074

A miniature internet of things (IoT)-based point-of-care testing (PoCT) fluorescence reader, able to perform both intensity and time-resolved measurements of different fluorescent tags, is presented. This low cost platform has been conceived for performing tests in low-resource and remote settings, displaying versatile performance and yet simple operation. It consists on an external case of 43 × 30 × 42 mm3 (built in a 3D-printer) where all the elements are fixed, including some basic optics (3 lenses and 2 filters), a laser diode and a custom designed Single-Photon Avalanche Diodes (SPADs) camera. Both, the laser and the camera are controlled by a Field Programmable Gate Array (FPGA) with IoT capabilities.
The PoCT was validated by detecting Plasmodium antigen in a fluorescent enzyme-linked immunosorbent assay (ELISA) using a fluorescence substrate. The results were compared to those provided in parallel by two commercial fluorescent plate readers. As it will be shown, the PoCT fluorescent readout was more sensitive than its colorimetric counterpart. Furthermore, the PoCT displayed similar signal trends and levels of detection than the bulkier and more expensive commercial fluorescence plate readers. These results demonstrate that the PoCT platform developed could bring the performance of central laboratory assay techniques closer to the end-user level.
•Miniature, Internet of things (IoT)-based, general-purpose point-of-care.•Ability to measure fluorescence intensity as well as time-resolved fluorescence.•Proprietary Complementary Metal-Oxide-Semiconductor Single-Photon Avalanche Diodes camera.•Validated by detecting Plasmodium antigen (Malaria) with an ELISA using a fluorescence substrate.•Comparison with bulky and expensive commercial plate readers.