Nickel Hexacyanoferrate-Based Sensor Electrode for the Detection of Nitric Oxide at Low Potentials

Recently transition metal hexacyanoferrates, analogues of Prussian Blue, have found application in electroanalysis for the detection of biologically relevant species. Our study describes the development of a novel electrode based on nickel hexacyanoferrate (NiHCF) for the sensorial NO determination. A NiHCF layer was deposited on platinum by cyclic voltammetry in a solution of nickel (II) chloride and potassium hexacyanoferrate (III). The electrode was found to be active for NO reduction. The interaction with the radical was studied voltammetrically within the range from 0 V up to +0.4 V vs. Ag/AgCl/1 M KCl. The most appropriate potential for an amperometric detection was determined to be +0.25 V due to the advantageous signal/noise ratio. The sensitivity of the electrodes was found to be 2.0–2.3 A M−1 cm−2. The sensor response of the most important interferents for NO analysis, hydrogen peroxide, ascorbic acid and nitrite, was measured and determined to be sufficiently low.