Biosensors TCNQ -based

For example, Carlo and co-workers modified the surface of a screen-printed carbon electrode with a thin layer of perfluorinated ion-exchanger films containing 7,7,8,8-tetracyanoquinodimethane (TCNQ) as mediator. It was found that the reduced form of TCNQ was oxidized at 0.4 V vs. the pseudo-reference electrode (Ag wire). The TCNQ-based biosensors were applied to a recovery test using egg, bovine meat, milk, and honey as food matrices. No false-negative or false-positive samples were detected in the assay. 

X. Llopis, A. Merkogi, M. del Valle and S. Alegret, Integration of a glucose biosensor based on an epoxy-graphite-TTF TCNQ-GOD biocomposite into a FIA system, Sens. Actuators B Chem., 107(2) (2005) 742-748. 

The biosensor described in this work, for the monitoring of pesticides, is based on acetylcholinesterase immobilized on the surface of screen-printed electrodes by adsorption and covered with a Nafion film. The incorporation of the TCNQ mediator in a carbon working electrode permits a dramatically decrease of the potential necessary for oxidation of thiocholine. 

---