Engineering a diagnostic platform based on a spatially resolved electrochemiluminescence immunoassay for low-plex biomarker detection at point-of-care: mild traumatic brain injury and cardiac applications

Advancements in diagnostics and disease management rely on measuring biomarkers in physiological samples. While multiplex biomarker detection holds great promise for improving disease detection, monitoring, and treatment, developing robust, user-friendly platforms capable of sensitive, decentralized analysis remains a significant challenge. In this article, we describe the development of a next-generation POC diagnostic platform capable of simultaneously quantifying multiple biomarkers from low-volume samples in a highly sensitive way. The platform incorporates a spatially resolved electrochemiluminescence immunoassay (SR-ECLIA) conceived on a single carbon electrode (allowing up to 50 individual biomarker spots/replicates to be realized simultaneously), a disposable microfluidic 3D printed cartridge engineered to handle the assay, and an advanced demonstrator tabletop ECL read-out device with application software for data acquisition and image analysis. The remarkable performance of the platform was demonstrated with the detection of two independent biomarker panels, one for mild traumatic brain injury and one for a cardiac application, with low, double-digit picogram per milliliter limits of detection (1-30 pg mL^-1). The proposed platform can be mass-produced at a low cost, and it is fundamentally adaptable to measuring other disease-related biomarker combinations, which could open new medical diagnostic avenues for sensitive low-plex biomarker testing at point-of-care (xPOCT).