A Pt/Pd-Decorated SnO₂-Based Electronic Nose for High-Precision Breath Analysis in Diagnosing SIBO

Exhaled human breath contains disease-related biomarkers, enabling non-invasive medical diagnostics. Small intestinal bacterial overgrowth (SIBO) is traditionally diagnosed through hydrogen measurement, a method that offers limited specificity and sensitivity. Herein, we introduce a simplified Pt/Pd-SnO₂ electronic composed of using only two sensing materials to achieve multi-gas detection. By simultaneously monitoring H₂, CO, ethanol, and acetone, the system provides a more informative diagnostic profile than conventional single-marker tests. Furthermore, the electronic nose employs dual operating temperatures (135 and 190 °C) to enhance gas discrimination. Machine learning-assisted signal processing further optimizes the system's ability to differentiate gases, enabling more accurate detection in clinical settings. It achieves a 93% classification accuracy and a mean squared error of 0.78 for gas concentration estimation. Importantly, the system was validated using real clinical breath samples collected after lactulose ingestion, where SIBO patients exhibited markedly elevated responses (7.62-18.77) compared to healthy individuals (2.45-4.91). This clinically validated, multi-gas platform offers improved accuracy and practical potential for SIBO diagnosis.