Oligo-phenylene vinylene (oligo-PV) with two picolinamide side-groups and six methoxy end-groups was synthesized in order to be a fluorescent sensing molecule. Various metal ion solutions (1.5× 10− 4 M) were added to the 1.5× 10− 6 M acetonitrile solution of the fluorescent molecule. The fluorescent emission spectra showed that, at about the same concentration (1.5× 10− 4 M), only Cu (II) ion can quench the fluorescent emission of the ...