A novel class of nonconjugated polysquaraines consisting of isolated chromophores bridged by variable receptor linkers has been synthesized by a two-step one-pot procedure. Substantial reorganization of the polymer backbone conformation occurs upon external physical or chemical stimuli, leading to characteristic absorbance and emission signal responses both at long wavelengths. This novel approach to macromolecular sensor design in which signal transduction is based on backbone folding induced exciton interactions affords sensors with tunable selectivity.