Novel poly(pyridinium) salts 4 were synthesized by polycondensation of 4,40-(1,4-phenylene)bis(2,6-diphenylpyrylium tetrafluoroborate) with calix[4]arene diamines for the purpose of biosensing to meet the shape adaptability with the secondary structures of biological macromolecules. The polymers were characterized by NMR, FT-IR, elemental analysis, inherent viscosity, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and wide-angle X-ray diffraction. Both the absorption and photoluminescence (PL) spectra of the polymers were also studied. Moreover, the interactions between polymer 4b and Pseudomonas fluorescens DNA were investigated primarily by a fluorescent titration method and transmission electron microscopy (TEM).
