Metal oxide semiconductors (MOSs) hold great promise for electronic devices such as gas sensors. The utilization of ZnO as a conductometric gas sensor material can be traced back to its early stages; however, its application has primarily been limited to high-temperature environments. A gas sensor based on highly porous and interconnected 3D networks of ZnO tetrapod (ZnO-T) micro-nano structures was fabricated via an easy chemical vapor deposition (CVD) method. Homemade instruments were utilized to evaluate the gas-sensing of the sample at room temperature. It exhibited good gas-sensing at room temperature, particularly with a response of up to 338.80% toward 1600 ppm ethanol, while also demonstrating remarkable repeatability, stability, and selectivity. Moreover, the unique gas-sensing properties of ZnO-T at room temperature can be reasonably explained by considering the effect of van der Waals forces in physical adsorption and the synergistic effect of carrier concentration and mobility. The aforementioned statement presents an opportunity for the advancement of gas sensors utilizing ZnO at room temperature.

Irritable bowel syndrome is a disorder of gut–brain interaction characterized by recurrent abdominal pain and altered bowel habits. Interactions among intestinal microorganisms and their metabolites, the epithelial barrier, mucosal immunity, and gut–brain signaling provide important insights into the heterogeneity of this condition. Engineered micro- and nanoscale carriers may improve the stability of orally administered bioactive agents and facilitate local intestinal delivery while modulating relevant pathological processes through protection of viable microorganisms, delivery of microbial metabolites, or direct regulation of host cells. This review examines major mechanisms underlying microbiota–immune interactions and summarizes advances in colon-targeted delivery, protective carriers for probiotics, plant-derived vesicle-like preparations, and microalgae-based hybrid systems. We further discuss the biological characteristics of different clinical subtypes and key translational challenges, including safety, quality control, and rigorous verification of therapeutic efficacy. In particular, evidence from direct irritable bowel syndrome studies is distinguished from findings in symptom-based models, other disease models, and fundamental mechanistic experiments.