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.