Organic charge transfer complex based printable biosensor

This paper describes the preparation of an organic charge transfer complex (CTC) based printable enzyme electrode. CTC crystals were prepared by mixing TCNQ powder with TTF solution (in acetonitrile). Glucose oxidase (GOD) was adsorbed at the CTC crystal surface in a monolayer. A printable paste was prepared by mixing GOD-adsorbed crystals with a binder and a solvent. This paste was applied to an electrode cavity and vacuum dried. A thin layer of gelatin was cast on the paste filled dried electrode, and cross-linked with glutaraldehyde in the dry condition. The sensors were fixed in a flow injection system, and continuously polarized at 0·15 V and 37°C, and the samples were automatically injected every 30 min. The developed sensors produced a huge response curren with an extended linear range of detection (0–100 mM) and the response was unaffected by the presence of normal oxygen in the buffer solution. The sensor showed excellent stability. The performance of the sensors was significantly influenced by the binder used.