Exploring dicyano-ferriprotoporphyrin as a novel electrocatalytic material for selective H2S gasotransmitter detection

Abstract Dicyano-ferriprotoporphyrin supported on Pt microelectrodes was investigated as a possible electrocatalytic material capable of selectively oxidizing the gasotransmitter H 2 S over interfering gasotransmitters CO and NO. The modified microelectrodes were able to detect H 2 S concentrations as low as 50 nM at a potential of 0.15 V vs . Ag/AgCl and demonstrated a 100–1000× higher sensitivity toward H 2 S than CO and NO, respectively. However, H 2 S detection was affected by the presence of CO and NO due, at least in part, to imperfect coverage of the underlying Pt microelectrode by the electrocatalyst. Incomplete CN − coordination and questionable stability of the porphyrin layer are also discussed as possible causes of CO and NO interference. Work is on-going to alleviate these limitations in order to fully develop the material into a practical electrocatalyst capable of selective H 2 S oxidation.