An overview is presented of the state-of-the art of electrochemical biosensors employing sol-gel materials. Low-temperature, porous sol-gel ceramics represent a relatively new class of materials for the immobilization of biomolecules. The rational design of sol-gel sensing materials, based on the judicious choice of the starting alkoxide, encapsulated reagents, and preparation conditions, allows tailoring of material properties in a wide range, and offers great promise for the development of electrochemical biosensors. The various advantages of biogels for amperometric biosensing are discussed, along with common designs of sol-gel-derived bioelectrodes, recent advances and trends, and future prospects. (C) 1999 Elsevier Science B.V. All rights reserved.