Amperometric Nitric Oxide Sensors: A Comparative Study

A comparative study among different types of modified electrodes for nitric oxide (NO) determination has been carried out. Detection limit, response time, reproducibility and selectivity versus some interferents as ascorbic acid, nitrite and dopamine were evaluated. Platinum (Pt) and glassy carbon (GC) electrodes have been assembled with homemade cellulose acetate membranes, commercially available membranes, Nafion and nonconducting polymers electrosynthesized directly onto the electrode surface. The most interesting results were obtained with a cellulose acetate membrane modified electrode and a Pt/poly[4,4'-dihydroxybenzophenone (4,4'-DHB)] electrode. The NO probes assembled showed a detection limit of 20 nmol/L and 40 nmol/L, respectively, for the cellulose acetate membrane modified electrode and for the Pt/poly[4,4'-dihydroxybenzophenone (4,4'-DHB)] electrode. A biological test on washed platelets stimulated by collagen was performed using the Pt/poly(4,4'-DHB) electrode.