Plasmonic hybrid modes in a multifunctional ZIF-8 layer for high performance volatile organic compounds sensing

Plasmonic sensors show great potential for their compactness, high sensitivity and versatile sensing capabilities. They often consist of optical nanoantennas and functional sensing materials. The design and fabrication of these sensors are thus becoming critically important to achieve better sensing performance. Here we demonstrate a hybrid plasmonic sensor composed of gold nanohole arrays and in -situ synthesized multifunctional zeolitic imidazolate framework (ZIF-8) layers. Mode coupling between the plasmon modes of the nanoholes and the waveguide modes in the ZIF-8 layers leads to narrow-band hybrid modes that are highly sensitive to the presence of ethanol vapor. A sensitivity of 50.1 pm/ppm is achieved in a concentration range of 455 to 1543 ppm. Ethanol vapor as low as 47 ppm was experimentally detected and the determined limit of detection of sensor is 11.8 ppm. The proposed sensor with its cost-effective fabrication and high performance provides a promising and competitive solution for low-cost, highly sensitive and real-time detection of volatile organic compounds in a variety of practical applications.