A novel electrochemical sensor based on nano-structured film electrode for monitoring nitric oxide in living tissues

A sensor exhibited high sensitivity and good selectivity for determination of nitric oxide (NO) was fabricated. The sensor was constructured by coating Nafion/multi-walled carbon nanoubes-chitosan-gold nanoparticles (Nafion/MWNTs-CS-AuNPs) film on glassy carbon electrode (GCE). Several key parameters affecting on the electrochemical response were optimized, such as the film thickness, applied potential and volume of Nafion. The sensor showed good linear relationship with the NO concentration in the range of 1.90 × 10−8 to 5.40 × 10−5 M and with the detection limit of 7.60 × 10−9 M (S/N = 3). Finally, the sensor was successfully applied to the monitoring of NO release from living tissues, including mouse kidney, heart, spleen and liver (a slice). NO release at micro-molar level can be detected while the NO donor l-arginine (l-Arg), nitroglycerin (GTN) and aspirin (ASA) was present. It was interestedly found that the capacities to induce NO generation were in the order of GTN > ASA > l-Arg when these stimulants were converted to the same concentration. In addition, the NO release is associated with the functional groups in these donors.