A simple, low-cost instrument for electrochemiluminescence immunoassays based on a Raspberry Pi and screen-printed electrodes

Abstract

A powerful, yet low-cost and semi-portable electrochemiluminescence (ECL) biosensing device is described. It is constructed around a Raspberry Pi single-board computer, which serves as the controller and user interface. The Pi is interfaced with an expansion board that controls the potential applied to a disposable screen-printed electrode and facilitates data acquisition from a photomultiplier tube (PMT), which detects the ECL emission from the sensor surface. As proof-of-concept, we demonstrate that this arrangement can quantitate tris(2,2′-bipyridine)ruthenium(II) ([Ru(bpy)3]2+]) with an estimated limit of detection (LOD) of 20 pM, and C-reactive protein with an LOD of 50 fg mL−1. The analytical performance of the Raspberry Pi-based setup is comparable to a conventional ECL configuration (computer, potentiostat and photodetector). The Raspberry Pi-based setup can replace a conventional ECL setup, at a fraction of the cost, without sacrificing sensitivity or versatility. The combination of a single-board computer and a sensitive light detector represents a significant step towards translating ECL instruments into mobile, point-of-care diagnostic platforms.