Detection of Ethanol Vapour Using Metal-Organic Frameworks as an Adsorbent Using Fibre Optics

Metal-organic frameworks (MOFs) based gas sensors are recently found to have potential in the detection of a few gases such as volatile organic compounds (VOCs). Apart from the gas detection using MOFs in other applications, detection of breath gases using MOFs is a challenge since they accompany moisture. In this work, ethanol being the major component of human breath under diseased conditions, a device is proposed for its detection. The device is simple to construct. It has silica fibre directional coupler (DC), the laser light source and a detector. ZIF-8 is used as an adsorbent for ethanol since it is hydrophobic in nature. Simulation of the proposed device shows that 10–100 ppm of ethanol gas adsorbed in ZIF-8, which brings out a low variation in the refractive index (RI) of the order of 10–4 is efficiently detected by the device.