Electrochemical biosensor for the detection of formaldehyde based on enzyme immobilization in mesoporous silica materials

Mesoporous silica materials have a potential application for enzyme immobilization, which increases the stability of enzymes. We report the development of a novel detection method based on biosensors comprising an immobilized enzyme in mesoporous silica materials (i.e.. FSM8.0 or P123-M), an electrochemical mediator (i.e., quinone), and an electrochemical cell, using the enzyme formaldehyde dehydrogenase. These biosensors exhibit a rapid response and high sensitivity, and they can detect 1.2 mu M of formaldehyde in an aqueous solution (corresponding to sub-ppb atmospheric concentration of formaldehyde). Furthermore, the sensors exhibit high selectivity, reusability, and a remarkable storage stability (stable over 80 days), indicating that formaldehyde dehydrogenase retains its highly ordered structure in these mesoporous silica materials. These results indicate that mesoporous silica materials can provide favorable methods for enzyme immobilization on the electrode and they are useful for developing high-performance electrochemical biosensors. (c) 2008 Elsevier B.V. All rights reserved.