We report the synthesis and electrochemical behavior of an original catalyst bearing a 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) unit and a pyrene group. Anchoring of this bi-functional molecule by π -stacking onto multiwalled carbon nanotubes allows the study of the electrochemical properties of the compound in the
immobilized state. These resulting functionalized TEMPO materials were used to detect iron(II) in solution
with an experimental detection limit of 3.9 × 10−8 mol L−1 and a linear range between 7.8 × 10−8 and
1.4 × 10−6 mol L−1.