Electrochemical Breath Sensors in Medical Diagnostics: Emerging Trends and Future Directions

With the rising prevalence of metabolic diseases, infections, and mental health disorders, there is a growing demand for noninvasive diagnostic tools that enable early detection and continuous health monitoring. In this context, exhaled breath biomarkers provide insight into physiological and pathological processes. Electrochemical breath sensors (EBSs) have emerged as a promising platform for rapid, real‐time, and cost‐effective disease tracking via the detection of volatile breath biomarkers, such as NH 3 , NO, and CO 2 . Recent advancements in electrode materials, biological recognition elements, and sensor architectures—spanning nanomaterials, enzymes, aptamers, and molecularly imprinted polymers—have enhanced the analytical performance of EBSs. Nonetheless, challenges remain in achieving biologically relevant detection ranges, selectivity in complex breath matrices, and long‐term environmental stability. This perspective article provides a critical overview of recent innovations and enduring limitations in EBS development. Beyond their role in monitoring physiological diseases, we highlight the emerging potential of EBSs for mental health assessment through the detection of gut‐derived metabolites in exhaled breath, such as short‐chain fatty acids, H 2 S, and ammonia, as indicators of gut–brain axis activity. The EBS‐based, noninvasive, real‐time measurement of these metabolites represents a transformative and underexplored approach for the diagnosis and treatment of psychiatric disorders.