Biosensor Innovations for Acute Kidney Injury (AKI) and Chronic Kidney Disease (CKD) Diagnostics.

Renal failure, characterized by declining kidney function and impaired blood filtration, arises from diverse conditions and medications that induce acute or chronic damage to glomerular, tubular, or vascular structures. Acute kidney injury (AKI) and chronic kidney disease (CKD) represent the two primary forms of renal disease, both associated with high morbidity, mortality, and clinical complexity. Current diagnostic criteria lack sufficient sensitivity and specificity, driving the search for biomarkers and rapid detection methods to enhance diagnostic precision. Electrochemical, plasmonic, nanoparticle-based, and molecular probe biosensors have emerged as promising platforms for point-of-care (POC) devices, leveraging advanced surface chemistry. These technologies play a crucial role in identifying and quantifying emerging AKI and CKD biomarkers, enabling timely interventions to mitigate renal impairment. This review comprehensively explores recent advances in biosensor design, fabrication methodologies, and strategies to optimize efficacy for diverse applications. We focus specifically on electrochemical, optical, and piezoelectric transduction principles due to their distinct advantages. Additionally, we detail the classification of biological recognition elements and transduction mechanisms and explore the role of materials in advancing noninvasive biosensor diagnostics for renal disease.