New materials for electrochemical sensing - II. Rigid carbon-polymer biocomposites

Rigid conducting carbon-polymer composites are ideal for the construction o f electrochemical sensors. The plastic nature of these materials makes them modifiable, permitting the incorporation of tillers before they are cured. A great number of biological materials can be immobilised by blending them with these composites to form new biocomposite materials. These biocomposi tes not only act as reservoirs of the biological material but may also cont ain catalysts, mediators and cofactors that improve the response of the res ulting electrochemical biosensors. One of the outstanding features of these conducting biomaterials is their rigidity, resulting in a high mechanical stability over time. Furthermore, the sensing surface can be renewed by a s imple polishing procedure. The proximity of the redox centres of the biolog ical material and the conducting sites on the sensing surface favours the t ransfer of electrons between electroactive species. This may in some cases permit the regeneration of the biological component without using cosubstra tes and mediators. These biocomposites are prepared easily and they show im proved electrochemical characteristics. This is very attractive for the mas s fabrication of amperometric biosensors. (C) 2000 Elsevier Science B.V. Al l rights reserved.