Sensor materials based on convex and concave chemistry-optical detection and mass sensitive devices

Based on the principles of convex and concave chemistry, sensor materials were developed for the detection of organic solvent vapors and ammonia. Species with pronounced electron donating properties are especially easy to detect with organic and inorganic cations. The resulting convex interactions permit the monitoring of ammonia by means of optical and resistive measurements. Concave chemistry was realized with liquid crystals, molecular holes, and channels. The incorporation of solvent vapors by cholesteric liquid crystals leads to absorbance changes by dichroic effects. Molecular holes and channels show an analogy to enzymes and are able to include guests which can be detected by mass-sensitive devices such as the quartz microbalance and the more sensitive surface-acoustic-wave oscillator.<>