An integrated microsystem with microneedle blood sampling and multi-analyte electrochemical sensing

Minimally invasive monitoring of metabolic biomarkers is critical for managing chronic diseases and guiding therapeutic interventions. Microneedle-based sampling platforms offer a less invasive alternative to traditional methods, reducing pain and the risk of infection. In this study, we reported the design, fabrication, and in vivo validation of a fully integrated, thumb-actuated microsystem for point-of-care (POC) blood sampling and electrochemical multi-biomarker analysis. The device couples a hollow microneedle with a paper-based plasma separation membrane and a custom two-channel electrochemical sensing circuit, enabling seamless sampling, separation, and proof-of-concept quantification of glucose and lactate with a single, user-friendly thumb press. Upon actuation, capillary forces draw a microliter-scale volume of blood through the microneedles into the separation membrane, yielding cell-free plasma for immediate electrochemical sensing of glucose and lactate. We successfully demonstrated the operation of this system in vivo for glucose and lactate testing in a rabbit, highlighting its potential for POC applications. The system represents a versatile approach for integrating microneedle blood sampling, paper-based microfluidics, and multi-analyte electrochemical sensors in next-generation POC devices.