Towards a MOF e-Nose: A SURMOF sensor array for detection and discrimination of plant oil scents and their mixtures

For the sensing, detection and discrimination of odors, well-defined active layers with large specific surface areas are required. We present an array of 3 quartz crystal microbalance (QCM) sensors coated with different thin films of crystalline, highly-porous surface-mounted metal-organic frameworks (SURMOFs). The sensor array is tested for the detection and discrimination of 6 different volatile plant oil (VPO) odors as well as of their mixtures with concentrations ranging from 1 mg/L to 40 mg/L. By data analysis with machine learning algorithms, accuracies for the classification and prediction of 99.97 % for the different pure odors and of 98.4 % for their mixtures were reached. Our results show, QCM sensors coated with SURMOF films can clearly discriminate the plant oil scents and their mixtures with very high success rate at low concentrations, indicating the way towards a MOF electronic nose, MOF e-nose.