A reagentless nitric oxide biosensor based on hemoglobin-DNA films

Nitric oxide (NO) is an important bioregulatory molecule in vivo. A reagentless, hemoglobin (Hb) based nitric oxide biosensor is prepared, based on the direct electrochemistry of Hb. Spectroscopic studies show that Hb maintains most of its 3-dimensional structure in the film, and keeps its reactivity with NO. The electrochemical reduction of NO is catalyzed employing the Hb modified electrode. Experimental results reveal that the peak current related to NO is linearly proportional to its concentration. It can detect traces of NO as low as 2.9 mu M. This biosensor is also shown to be simply constructed, biocompatible and stable. (C) 2000 Elsevier Science B.V. All rights reserved.