The synergistic combination of biological entities (such as proteins, bacteria, cells, viruses) and ceramics has lead to an exciting new class of materials that may serve as the core components of the next generation of biosensors. The performance, functionality and application of such hybrid bio- ceramics systems will depend on the activity, functionality, and interaction of entrapped biomolecules with the surrounding ceramic matrix. Requirements for successful bioencapsulation include structural, thermal and chemical stability, functionality, and accessibility of biologicals upon encapsulation. Urease-doped MoO3 sol-gel provides a model system of enzyme-doped metal oxide and a novel biosensing element, that is an active substrate for the detection of urea. The fast and selective response of the metal oxide matrix to gases(e.g. NH3) that are released from the specific biochemical reaction between the biological dopant (urease) and the analyte of interest (urea) allows for the development of conductimetric biosensing probes.