BIOSENSORS IN MEDICAL DIAGNOSTICS: PRINCIPLES AND APPLICATIONS

Abstract

Medical diagnostics changed direction in 1962 when the first enzyme electrode showed that a biological recognition molecule and a simple transducer, working together, could measure a clinically relevant substance in real time. That founding idea has since grown into one of the most consequential technology platforms in modern medicine. Biosensors today detect glucose in the fingertip, identify viral pathogens in saliva, catch cardiac injury within minutes in the emergency department, and screen for cancer biomarkers in blood samples too faint for earlier methods to resolve. This chapter examines the science behind all of these capabilities: the structural logic shared by every biosensor, the major transduction platforms and the clinical tasks they are suited to, and the advanced technologies — nanomaterial engineering, CRISPR-based nucleic acid detection, wearable continuous monitoring, and AI-integrated sensor arrays — that are defining the field's next chapter. It also addresses the practical obstacles that slow clinical translation: biofouling, matrix interference, manufacturing consistency, and regulatory complexity. Taken together, the picture is of a technology that has already transformed diagnostics and is positioned to transform it again.