Optical ammonia sensors with detection limits in the ppb range
Sensitive and selective sensor materials for on-line monitoring of gaseous and dissolved ammonia are of high interest . Application areas for continuous ammonia measurements at sub-ppm levels are food monitoring and clinical uses like breath analysis (50-2000 ppb) [2,3]. The survey of the ammonia concentration in drinking and surface waters for environmental analysis, fish farms, bioreactors and aquariums is another example for the use of sensors with detection limits at less than 1 ppb, because ammonia levels as low as 25 ppb are known to be toxic to organisms [4,5].
Sugar responsive fluorescent nanospheres
In this research project we develop sugar responsive nanosensors based on the osmotic presure driven swelling of an amphiphilic polymer. The volume transition is tracked by resonance energy transfer (RET) of co-polymerized donor and acceptor dyes.