Urease templated precipitation of silica synthesized by sol-gel chemistry produces a composite material allowing high urease activity. This study investigates the structural properties of the composite material that allow for the retention of the urease hydrolysis activity. Scanning (SEM) and transmission (TEM) electron microscopy reveal that the composite has a mesoporous structure composed of closely packed spherical structures similar to 20-50 nm in diameter. Brunauer-Emmett-Teller (BET) analysis revealed that the surface area and pore volume of the composite prepared under the conditions of 50 mM urea and 25 degrees C is relatively high (324 m(2)/g and 1.0 cm(3)/g). These values are equivalent to those of usual mesoporous silica materials synthesized from the self-assembly of triblock copolymers as organic templates. In addition, after encapsulating in a sol-gel silica matrix, urease retained high activity (similar to 90% of the activity compared with native urease). Our results suggest a new method for synthesizing mesoporous silica materials with highly tunable pore sizes and shapes under mild conditions. (c) 2012 Elsevier B.V. All rights reserved.