Formaldehyde Gas Sensor Based on Hybrid Film: Graphene/Enzyme

Through a simple fabrication process, we fabricate tiny and cheap formaldehyde gas sensor. To do that, we used the hybrid film that consists of Chemical Vapor Deposition (CVD) graphene and formaldehyde dehydrogenase (FALDH). Since graphene sensitively shows an electrical response with the concentration of hydrogen cation in the solution, the novel graphene-based gas sensors can quickly respond with formaldehyde gas. The sensor shows the response with a low concentration of formaldehyde gas up to ppb level. It also has a great selectivity for the formaldehyde gas because it is based on the enzyme reaction. The mechanism of the reaction can be clearly explained by chemical equations.