Luminescence of the carbonyl group has been known for a long time. In this study, a range of molecular weights (2x10³ to 1x10⁶ Da) of poly(acrylic acid) (PAA) are irradiated under ultraviolet light. The irradiated PAA experiences a surprising linear increase in luminescence intensity, with peak wavelength at approximately 450nm. Both multilayer films assembled by successive adsorption of oppositely charged polyelectrolytes and spin-cast films were prepared. Multilayer films were composed of the strong polycation poly(dimethyldiallyl ammonium chloride) (PDDA) and negatively charged PAA as the polyanion. Luminescence lifetime measurements are presented both for PAA in solid state and in aqueous solution. Various deposition conditions for solid state films were investigated such as solution pH, salt concentration, and presence of metal ions. Changes in luminescence were monitored optically, while film thickness and morphology were followed by atomic force microscopy. The effects on film thickness, emission intensity and luminescence lifetime are reported.