Conductance-photoacoustic spectroscopy for fast and concurrent sensing of hydrogen and hydrocarbons.

Accurate and rapid detection of hydrogen and hydrocarbons is critical for safety and efficiency in modern energy, industrial, and environmental systems. However, selective and simultaneous quantification of these species remains a significant technical challenge. Here, we introduce conductance-photoacoustic spectroscopy (ConPAS), an integrated sensing approach that combines conductance-based resonance modulation with quartz-enhanced photoacoustic spectroscopy in a single device. By bridging a quartz tuning fork (QTF) with a catalytic platinum microwire, ConPAS enables concurrent extraction of hydrogen and hydrocarbon concentrations from a unified electrical signal: hydrogen is quantified by frequency analysis, while hydrocarbon content is determined by amplitude analysis simultaneously. Experiments demonstrate minimum detection limits of 0.69 % for hydrogen, 40.26 ppm for propane, and 133.7 ppm for methane, with millisecond response time and excellent linearity (R² > 0.99). The modular architecture allows flexible adaptation to other analytes via material substitution, offering a scalable and versatile solution for simultaneous, multi-component gas sensing. This work establishes ConPAS as a powerful, calibration-compatible platform for integrated gas analysis in hydrogen-enriched environments, with broad implications for safety monitoring, process control, and advanced energy applications.