Electrochemical biosensor for the detection of formaldehyde based on encapsulation of an enzyme, into the nanoporous-walled silica nanotube-inorganic composite membrane

We prepared silica nanotube with nanochannels in the columnar pores of a commercial anodic alumina membrane (F127-MST), and then made up biosensors for detection of formaldehyde based on immobilized enzyme as formaldehyde dehydrogenase in F127-MST using mediator (i.e., quinone) and an electrochemical cell. The formaldehyde dehydrogenase confined in membrane showed a very high enzymatic activity, besides much higher electron transfer to electrode than the native. These results indicate that F127-MST can provide favorable methods for enzyme immobilization on the electrode and they are useful for developing high-performance electrochemical biosensors for the detection of formaldehyde.