Keywords:gas sensor, metal oxide, nanowire
The gases exhaled by a human may contain more information than we think. Many of them related to a human health condition or different diseases have been proved. For the goal of breath or skin gas detection system in human health care or medical application, gas sensors have attracted a lot of attention. The high-performance gas sensor is a fast and effective way to realize extremely early state, non-invasive and continuous monitor system. Metal oxides gas sensors have substantial attention from both scientific and practical perspectives due to their easy production, low cost and good portability. Sensitivity and selectivity are the biggest challenges to apply in real-time health monitoring. In this work, how size effect effects sensitivity will be researched by controlling the grain size. How noble metal catalyst doping and heterojunction contribute to improving the sensitivity. And how zeolite overcomes the poor selectivity of metal oxide gas sensors.