Selective gas nanosensors with multisize CdSe nanocrystal/polymer composite films and dynamic pattern recognition

We introduce a concept for selective chemical sensing based on different size semiconductor nanocrystals incorporated into a preselected polymer matrix. When CdSe nanocrystals of different sizes (2.8 and 5.6 nm diam) were incorporated into a polymer film, each size of the nanocrystals demonstrated a distinct photoluminescence response pattern (excitation at lambda=407 nm) upon exposure to polar and nonpolar vapors in air at atmospheric pressure. When this composite response was processed using a multivariate analysis, a single film with different size CdSe nanocrystals served as a selective sensor. (c) 2006 American Institute of Physics.