An artificial olfactory sensor based on flexible metal–organic frameworks for sensing VOCs

An artificial olfactory sensor using seven flexible metal–organic frameworks (MOFs) was designed to detect volatile organic compounds (VOCs) with high selectivity. Owing to its unique colorimetric mechanism, the flexible-MOF-based colorimetric sensor array enables the detection of less-reactive VOCs to which conventional dyes are insensitive. In addition, the flexible MOFs show excellent reversibility toward various VOCs, reusability for repeated cycles toward a single VOC, and storage stability under different humidity and time conditions. Furthermore, the flexible MOF sensor array demonstrates the potential to identify late blight in the tomato crop via the differentiation of the composition of VOCs released by Phytophthora infestans (P. infestans)-infected leaves and those of a healthy control.