Paper-Based Electrophoretic Bioassay: Biosensing in Whole Blood Operating via Smartphone.

Point-of-care (PoC) tests are practical and effective diagnostic solutions for major clinical problems, ranging from the monitoring of a pandemic to recurrent or simple measurements. Although, in recent years, a great improvement in the analytical performance of such sensors has been observed, there is still a major issue that has not been properly solved: the ability to perform adequate sample treatments. The main reason is that normally sample treatments require complicated or long procedures not adequate for deployment at the PoC. In response, a sensing platform, called paper-based electrophoretic bioassay (PEB), that combines the key characteristics of a lateral flow assay (LFA) with the sample treatment capabilities of electrophoresis is developed. In particular, the ability of PEB to separate different types of particles and to detect human antibodies in untreated spiked whole blood is demonstrated. Finally, to make the platform suitable for PoC, PEB is coupled with a smartphone that controls the electrophoresis and reads the optical signal generated. It is believed that the PEB platform represents a much-needed solution for the detection of low target concentrations in complex media, solving one of the major limitations of LFA and opening opportunities for point-of-care sensors.