Sonolytic doping of poly(1-naphthylamine) with luminol: influence on spectral, morphological and fluorescent characteristics

Doping is one of the most facile techniques adopted to improve the optoelectronic properties of conducting polymers. The present preliminary work reports, for the first time, chemical doping of poly(1napthylamine) (PNA) with (5-amino-2,3-dihydro-1,4phthalazine- dione) widely known as luminol, to study its influence on the spectral, morphological, and optical properties of PNA. PNA was doped with luminol in acidic, basic, and neutral media. The neutral polymer and its doped forms were characterized using FTIR, UV-visible, XRD, and TEM analyses. FTIR studies confirmed doping of PNA by luminol, while UV-visible and fluorescence studies revealed the changes in the electronic structure of PNA upon doing. Confocal microscopy revealed intense red emission confirming that the polymers could be used for near infrared fluorescence imaging.