Applications of Metal Compounds and Cholesteric Liquid Crystals for Chemical Sensing

Abstract

Chemical sensing of volatile organic compounds (VOCs) has attracted much attention. However, challenges such as how to produce low-cost, portable VOC sensors with good sensory performance remain. Motivated by these challenges, we developed VOCs sensors from two potential materials. The first one is metal compounds because they can be used as molecular receptors based on metal-ligand interactions. Firstly, metal phthalocyanines were added as dopants in transparent polymers for portable colorimetric amines sensor. We also studied the surface ligands effect to colorimetric response of Cu2+ to ammonia. The second material exploited here is cholesteric liquid crystals (CLCs). We developed colorimetric CLCs arrays and thin films for VOCs detection. To improve CLCs selectivity, CLCs were doped with suitable molecular receptors. Finally, we utilized CLCs to develop integrated VOCs sensors with microfluidic channels. This work shows the potential utility of metal compounds and CLCs as low-cost and portable sensors for detecting VOCs.