Gas sensor materials based on semiconductor nanocrystal/polymer composite films

We introduce here a new concept for selectivity improvement in chemical sensing. We have found that when semiconductor CdSe nanocrystals of different size were incorporated into a polymer film and photoactivated, each size of CdSe nanocrystals unexpectedly demonstrated its own photoluminescence (PL) response pattern upon exposure to polar and nonpolar vapors. When this composite response was processed using multivariate analysis, a single film with different size CdSe nanocrystals served as a selective sensor.