DEVELOPMENT OF OLIGO(p-PHENYLENE EHYNYLENE)(OPE) APPLICATIONS AGAINST CHEMICAL AND BIOLOGICAL THREATS

Four new applications of oligo-phenylene ethynylene (OPE) and poly-PE (PPE) compounds for detection and destruction of biological and chemical threats have been investigated. Mixed surfaces composed of PPEs and a thermoswitchable polymer were created, and were shown to be able to capture, kill, and reversibly release pathogenic bacteria. In order to develop fluorescent sensors for CW agents, the spectral changes of OPEs with surfactants and malathion (a simulant for nerve agents) were measured. Formation of OPE-dimers in the presence of surfactants can cause fluorescence enhancement (turn-on) or quenching (turn-off). Among six positive and negative OPEs, only OPEs with ethyl ester (COOEt) functional groups show fluorescence enhancement in the presence of surfactants, and quenching in the presence of malathion. In order to improve the lower detection limit (which is about nM) and specificity, a new OPE molecule with oximate (R-N=O) functional groups is being synthesized and tested. Finally, PE compounds were investigated as potential dyes for twophoton microscopy, and were found to be cell-penetrant, to have a good two-photon excitation cross-section, and hence to be useful as a nucleic acid stain for mammalian cells.