Bioinspired supramolecular arrayed heterojunction-based room-temperature sensor for high-performance gas detection

Nitrogen dioxide (NO2) has been severely polluting the atmosphere and deteriorating human beings’ sustainable lives. Therefore, development of gas sensors for high-selectivity and high-sensitivity detection of NO2 has been attracting increasing attention. The state-of-the-art inorganic NO2 gas sensors require harsh fabrication conditions or toxic materials, making the devices intrinsically eco-unfriendly. Furthermore, in most cases the sensors work at high temperatures. These disadvantages severely impede their practical applications. Herein, we report a room-temperature and highly-integrated NO2 sensor composed of p-type self-assembled peptide fibrillar nanoforests (SPNFs) scaffolded with n-type SnO2 nanoparticles (NPs) heterojunctions. The p-n conformations provide efficient access to target gases and allow reliable electron transformations, while the SPNFs afford a large specific surface area and multiporous structures for gas adsorption and SnO2 NPs dispersion, resulting in an ultrahigh selectivity for NO2 detection. Especially, the sensing performance can be optimized by modulating the thickness and density of the SPNFs, showing a high response, short response and recovery times, along with a low detection limitation. Our strategy demonstrates the development of a bioinspired platform by utilizing peptide self-assemblies to fabricate integrated sensors for polluting gas detections.