Aquivion–Poly(N‐vinylcarbazole) Holistic Flory–Huggins Photonic Vapor Sensors

A holistic detection system, in principle sensitive to any molecular species in the vapor phase is proposed. The sensor consists of a polymeric multilayered distributed Bragg reflector made of a perfluorinated polar polymer, Aquivion, and a nonpolar polymer, poly(N‐vinylcarbazole). Alternated layers of the two polymers provide a characteristic optical response that depends on the chemical species intercalating within the structure. Such differences arise from Flory–Huggins polymer–solvent interactions. Then, the presence of polar, nonpolar, and perfluorinated moieties in the structures, potentially, allows sensitivity to any molecular species, providing a detection system with no need for any additional chemical receptors. As a proof of concept, the study demonstrates the sensitivity of the sensor to very diverse classes of molecules in the vapor phase including perfluorinated, nonpolar hydrophobic, and hydrophilic species and the capability to distinguish them, even in binary mixtures. Additionally, a connection between the dynamic temporal response of the sensors and the chemical–physical properties of the analytes, their concentration, and effective diffusion coefficient within the polymer structure is revealed. A fully polymeric photonic colorimetric sensor that is selective towards a wide range of volatile chemicals is designed. Owing to the presence of fluorinated, polar, and nonpolar moieties, interactions with different analytes produce unique color change at a characteristic rate. A correlation between the response of the sensor and the physiochemical properties of the analytes is revealed.