A highly sensitive and low-power sensing platform for detecting ethanol molecules by interfacing high-purity, large-diameter semiconducting carbon nanotube transistors with a metal–organic framework layer is presented. The new devices outperform similar graphene-based metal–organic framework devices by several orders of magnitude in terms of sensitivity and power consumption, and can detect extremely low ethanol concentrations down to sub-ppb levels while consuming only picowatts of power. The exceptional sensor performance results from the nanotube transistor\u27s high on/off ratio and its sensitivity to charges, allowing for ultra-low power consumption. The platform can also compensate for shifts in threshold voltage induced by ambient conditions, making it suitable for use in humid air. This novel concept of MOF/CNTFETs could be customized for detecting various gaseous analytes, leading to a range of ultra-sensitive and ultra-low power sensors