As a commonly used disinfectant in clinical medicine, glutaraldehyde is highly volatile and possesses a ppb-level environmental permissible threshold. Developing a sensitive and portable gas sensing platform for low-concentration glutaraldehyde detection is crucial. Herein, we present an efficient chemiresistive sensor that enables the low-concentration and rapid detection of glutaraldehyde. The sensor is based on SnO 2 nanofibers (NFs) functionalized with bimetallic PtPd nanocatalysts (NCs). Square-shaped PtPd NCs with a uniform edge length of 8.2 nm are synthesized by a hydrothermal method and then introduced into SnO 2 NFs. The resulting PtPd-SnO 2-1 sensor yields a rapid, sensitive, and reversible response to glutaraldehyde gas, with a theoretical detection limit of 10.7 ppb. The remarkable gas sensing properties are attributed to the sensitization and synergistic effect of PtPd NCs, thereby promoting the formation of chemisorbed oxygen species and enhancing the response. Density functional theory (DFT) results show that the catalytic effect of bimetallic PtPd NCs leads to an increase in adsorption energy as well as charge transfer, and Pd-doping-induced shift of the d-band center. As a key component, the sensor is integrated into a wireless glutaraldehyde sensing platform, which integrates a circuit board and a smart terminal, thus achieving convenient and effective glutaraldehyde detection. The finding indicates that the PtPd-SnO 2 sensor is a potential candidate for practical glutaraldehyde detection.