Autonomous dual-function sampling platform for safe primary blood analysis

Safe and accurate analysis of blood biomarkers in the primary clinical settings is important for monitoring patients with chronic kidney disease (CKD). However, current technologies for blood biomarker analysis either rely on time-consuming and sophisticated hospital-based equipment, or lack the sensitivity required for ultrasensitive detection, while simultaneously posing considerable health risks to frontline practitioners due to direct blood handling and potential exposure to infectious agents. Here we present an innovative dual-function electrochemical sensing system, which was integrated within a commercial blood sampling vacutainer, for the simultaneous analysis of blood pH and glucose levels. The electrochemically deposited iridium oxide (IrOx) is used for the fabrication of pH sensors on a flexible Kapton film with a super-Nernstian response of 71.28 mV/pH. While a glucose oxidase (GOx) and Prussian blue pair is used in combination with gold nanoparticles (AuNPs), chitosan, and graphite composites for the enhanced detection of glucose with a sensitivity of 46.5 μA·mM⁻¹ ·cm⁻². In addition, a bespoke readout system, which includes a V₂O₅-based high energy density battery, a low power consumption integrated circuit, and a Bluetooth communication module, has been designed to enable robust wireless data transmission and remote diagnosis. This sensing platform has been validated using blood samples from CKD patients in the primary clinical settings, with superior sensitivity, selectivity, and reproducibility over the gold standard methods. Most importantly, the design of this platform simplifies the diagnostic procedures and eliminates the health risk to expose the frontline practitioners to blood samples throughout the sample-to-result process.