MOF-derived Pt-ZnO nanotubes: toward advanced chemical sensors with high sensitivity and selectivity.

The detection of volatile organic compounds (VOCs), particularly acetone, is critical for applications in environmental monitoring and medical diagnostics, including diabetes detection. Conventional metal oxide semiconductor sensors face challenges such as poor selectivity, high operating temperatures, and limited stability. This study addresses these limitations by developing Pt-doped ZnO nanotubes (Pt-ZnO NTs) using a coaxial electrospinning andin-situgrowth method. The process effectively incorporates ZIF-8-derived hollow ZnO structures and uniformly distributed Pt nanoparticles to enhance gas sensing performance. Key findings reveal that the 1% Pt-ZnO NTs sensor exhibits exceptional acetone sensitivity (R_a/R_g= 48.2 for 10 ppm), broad detection range (81.2 ppb-50 ppm), reduced operating temperature (240 °C), and robust selectivity against interfering gases. Advanced characterization and theoretical density functional theory analysis show that Pt doping increases oxygen vacancy concentration, enhances electron transport, and reduces the material's band gap, contributing to superior sensing capabilities. Additionally, the sensor demonstrates excellent stability, repeatability, and practical applicability in distinguishing diabetic and healthy exhaled breath samples. This research introduces a novel gas sensing platform that integrates metal-organic framework-derived structures and noble metal catalysts, offering significant advancements in sensitivity, selectivity, and reliability for VOC detection.