Optical biosensors based on Prussian Blue films

Optical biosensing schemes based on enzymatically modified inorganic/organi c transparent films predominately composed of Prussian Blue are demonstrate d. The composite film, which is non-electrochemically deposited on a non-co nducting support, is used as an optical transducer for flow-through biosens ors based on hydrolases and oxidases. Urease and glucose oxidase are utiliz ed as model enzymes. Action of the urea biosensor is based on optical pH se nsitivity of Prussian Blue indicator. The glucose biosensor is acting as fi rst-generation optical biosensor based on in situ generated Prussian White transducer for hydrogen peroxide. These simple, single-pass transmission op tical biosensors exhibit sensitivity in the millimolar range of concentrati on. The biosensors are very stable owing to presence of a poly(pyrrolylbenz oic acid) network in the composite material. This organic polymer plays a d ual role as a binding agent for inorganic material and as a functionalized support for strong covalent immobilization of enzyme molecules.