Optical sensing of cyanide using hybrid biomolecular films

The selective sensing of cyanide anions in water has been studied using a hybrid biomaterial composed of a mesoporous TiO2 film of crystalline nanoparticles and the protein hemoglobin. The mesoporous structure of the film prevents protein unfolding and also stabilizes the oxidized form of the prosthetic groups. Low-levels of cyanide anions (<0.2 ppm (0.2 mgr/L)) can be detected by monitoring the changes in the optical properties of the hybrid biomolecular films upon cyanide binding to the heme groups.