Composition-Tuned PdPt–WO3 Yolk–Shell Heterostructures with Engineered Catalytic Interfaces for Selective Isoprene Detection

Abstract

Reliable isoprene detection is critical for personalized healthcare; however, achieving molecular discrimination at trace concentrations remains challenging. Herein, we report a one-pot spray pyrolysis strategy for the precise composition engineering of bimetallic PdPt nanoclusters in situ integrated with yolk–shell WO3 spheres for high-performance isoprene sensing. Systematic compositional modulation revealed that Pt-rich PdPt–WO3 exhibited a high isoprene sensing performance (resistance ratio of 581 to 1 ppm at 275 °C) and marked selectivity (response ratio >168) over interference gases. Comprehensive investigations combining gas-sensing analysis, catalytic characterization, and density functional theory/molecular dynamics (DFT/MD) simulations elucidate that tailoring the Pd/Pt ratio promotes oxygen vacancy formation, thereby improving adsorption and charge transfer, while simultaneously enhancing isoprene reforming/oxidation activity. The sensor also exhibited reliable operation under high humidity and long-term cycling conditions. By integrating the robust sensing platform with a Residual Network-based deep-learning framework, we developed a portable wireless monitoring system capable of intelligent gas recognition and reliable isoprene quantification. This study offers a generalizable design strategy that combines compositional tuning and structural engineering for next-generation functional oxide-based chemiresistors in personalized healthcare applications.