Development of an Ultrasensitive Acetone Breath Sensor Based on Pt-Modified ZIF-8-Derived SnO₂/ZnO Heterojunctions...

Diabetes is one of the leading chronic diseases that cause disability and death. Regular monitoring of diabetes is crucial for improving overall public health. Acetone in exhaled breath can serve as a biomarker for diabetes monitoring. However, its concentration is extremely low, which imposes high demands on sensors in terms of sensitivity and detection limits. To date, many acetone sensors have been developed using single-component metal oxides, noble metal catalysis, or single-heterojunction engineering. However, these sensors often face a trade-off between key sensing parameters, and few meet the practical requirements for portable, real-time breath detection. Herein, we propose a Pt-modified SnO₂/ZnO composite derived from zeolitic imidazolate framework-8 (ZIF-8) via a ternary synergistic modification strategy as a high-performance sensing material for the detection of acetone in exhaled breath. The Pt-SnO₂/ZnO sensor demonstrates a high response (R_a/R_g) of 103.68 toward 100 ppm acetone, with fast response and recovery times of 6.8 s and 15 s, respectively, and an ultralow detection limit of 0.2 ppm. It also demonstrates low hysteresis and excellent long-term stability, with only a 7.6% decrease in response to 30 ppm acetone after 4 weeks of storage. This comprehensive performance breaks the performance trade-off widely existing in reported acetone sensors and is significantly superior to that of most state-of-the-art single-component and single-modified acetone sensing materials. The enhanced sensitivity of the Pt-SnO₂/ZnO sensor toward acetone is mainly attributed to the synergistic interaction between Pt nanoparticles and the SnO₂/ZnO matrix, which facilitates the formation of additional oxygen vacancies and enhances the specific surface area of the material. Furthermore, a portable breath analysis system based on the Pt-SnO₂/ZnO acetone sensor has been developed and validated via clinical breath tests to allow for non-invasive, real-time monitoring of diabetes. This system could significantly alleviate the discomfort typically associated with traditional testing methods.