Chemically sensitive microelectrochemical devices. New approaches to sensors

A new kind of microelectrochemical sensor is to be described involving two redox active molecules immobilized onto a microelectrode. One redox species is chemically insensitive with respect to variation in E _1/2 , e.g. a ferrocene derivative, and serves as an internal reference in a linear sweep voltammogram. The second species is chemically sensitive, e.g. a pH sensitive quinone or a CO sensitive organometallic, which has an E _1/2 that varies with the changes in the chemical environment. A linear sweep voltammogram thus shows two waves, one for the reference molecule and one for the indicator molecules. The separation of current peaks for the two types of molecules can be related to the concentration of the analyte, e.g. [H⁺]. Surface derivatization, proof-of-structure, and proof-of-concept sensor functions will be demonstrated.