Transforming Renal Diagnosis: Graphene‐Enhanced Lab‐On‐a‐Chip for Multiplexed Kidney Biomarker Detection in Capillary Blood

Abstract

Chronic kidney disease (CKD) is a significant global health concern, impacting over 10% of the world population. Despite advances in home‐based treatments, CKD diagnosis and monitoring remain centralized in large laboratories. This work reports on the development of a Graphene‐based Lab‐On‐a‐Chip (G‐LOC) for the self‐testing of multiple renal function biomarkers in capillary blood. G‐LOC integrates bioelectronic sensors with a 3D‐printed microfluidic system that enables the multiplex quantification of urea, potassium, sodium, and chloride, from one drop of blood. The potentials of three graphene sensors modified with ion‐selective membranes and enzymes are simultaneously measured. The analytical performance of the test is evaluated in terms of linearity, accuracy, and coefficient of variability (CV). Accuracy values higher than 98.7%, and CV values lower than 10.8% are obtained for all the biomarkers. Correlation and Bland–Altman plots show good correlation (slopes in the range of 0.94–1.15) and high agreement of G‐LOC with a reference method. It is also demonstrated that the test can correctly differentiate biomarker levels normally obtained for healthy people, early‐stage CKD, and end‐stage CKD. Finally, user experience is studied with a group of untrained volunteers who highlight the simple usability of the test and its suitability for at‐home diagnostics.