Amperometric detection of nitrite in water samples by use of electrodes consisting of palladium-nanoparticle-functionalized multi-walled carbon nanotubes

An amperometric determination of nitrite in different water samples was evaluated using palladium nanoparticles (PdNPs) decorated functionalized multiwalled carbon nanotubes (f-MWCNT) modified glassy carbon electrode. The f-MWCNT/PdNPs composite modified electrode was prepared by electrodeposition of PdNPs on the surface of f-MWCNT modified electrode. The parameters such as effect of number of cycles of PdNPs deposition, drop coated amount of f-MWCNT and effect of pH were optimized and discussed in detail. As-prepared f-MWCNT/PdNPs composite modified electrode exhibits excellent electrocatalytic activity towards the oxidation of nitrite compared to MWCNT, f-MWCNT and PdNPs modified electrodes. Amperometric i-t method was used to determine nitrite and the response of the nitrite on modified electrode was linear over the concentration from 0.05 to 2887.6 μM. The response time of the sensor was estimated as 3 s with the detection limit of 22 nM. The fabricated f-MWCNT/PdNPs composite modified electrode shows its satisfactory practical ability in nitrite containing different water samples, which authenticate its potential ability for determination of nitrite.