3D-printed integrated electroanalytical device for ischemic stroke point-of-care testing

Ischemic stroke represents one of the main causes of death and disability, affecting approximately 15 million people every year [1]. Numerous clinical studies have revealed a strong correlation between brain damage caused by ischemia and elevated iron levels in the affected tissues [2]. In this context, transferrin (Tf), a key protein involved in iron transport and metabolism, has emerged as biomarker. In particular, the transferrin saturation (TSAT) ratio, i.e., the proportion of transferrin-bound iron (Tfbound iron) to the total iron-binding capacity (TIBC), has emerged as a critical parameter in the diagnosis and monitoring of ischemia [3]. Recent advancements in micro- and nanotechnologies have facilitated the development of smart biosensors and advanced analytical tools. Among these, additive manufacturing, particularly 3D printing, has gained significant traction due to its affordability, versatility, and customizability. Indeed, electrochemical microfluidic devices produced using 3D printing are emerging as promising tools for the development of the next generation of point-of-care testing (POCT) devices [4]. Herein, we report the development of a 3D-printed electrochemical microfluidic device to assess TSAT. The device has been designed and manufactured to integrate the immunoassay step, a crucial component in isolating transferrin from serum samples. This innovation addresses a key challenge in this field, which has limited the development of smart analytical devices. Indeed, the 3D device incorporates the immunoassay procedure, enabling the simultaneous electrochemical detection of Tfbound iron and TIBC. This approach allowed for accurate TSAT assessment in serum samples obtained from patients diagnosed with ischemic stroke.