“…So far, the most widely used NH 3 gas sensors are based on bulk or nanostructured metal oxide semiconductor materials that require a high working temperature of typically 200–450 °C. − This leads to a high-power consumption and limited application scenarios for wearable and portable electronics that are supposed to attach to or be in the close proximity of skin surfaces. Therefore, in recent years, intensive research efforts have been devoted to the development of advanced gas sensors that can operate at room temperature (RT), with nanostructured channel materials, such as silicon nanowires (SiNWs), − conductive polymer, , carbon nanotubes, , graphene, or their composite. , Particularly, the one-dimensional SiNW channels, with high surface-to-volume ratio and chemical activity on the sidewall, have been considered as the ideal choice for NH 3 gas sensing that can work at RT, thanks to an efficient adsorption of gas molecular species on the sidewall of tiny SiNW channels, typically with diameter <80 nm. , In addition, the high stability and biocompatibility of SiNWs are also beneficial for developing a new generation of wearable and portable chemical/biological sensors. − …”