Fabrication of nano-copper/carbon nanotubes/chitosan film by one-step electrodeposition and its sensitive determination of nitrite

In this paper, Cu nanoparticles/carbon nanotube/chitosan (Cu-nano/CNTs/CS) film was one-step electrodeposited onto the glassy carbon electrode (GCE), which fabricated a Cu-nano/CNTs/CS/GCE sensor to detect nitrite. One-step electrodeposition of CNTs and Cu-nano with the chitosan (CS) hydrogel was achieved, and the whole procedure takes only several minutes. Scanning electron microscopy (SEM) image demonstrated that the Cu nanoparticles coated on CNTs/CS were uniform, with an average size of 30 nm. The effects of Cu2+. CNTs and CS concentration in the mixture together with electrodeposition time and determination conditions such as applied potential, pH value on the current response of Cu-nano/CNTs/CS/GCE toward nitrite were optimized to obtain the maximal sensitivity. In addition, electrochemical experiments revealed that the modified electrode showed high electrocatalytic activity to the reduction of nitrite ion (NO2-). The linear range for the detection of NO2- was 1.0 x 10(-7) M to 2.5 x 10(-3) M with a high sensitivity of -48.92 mu A mM(-1), and the response was very fast (less than 2 s). A low detection limit of 2.4 x 10(-8) M (S/N =3) for NO2- was achieved. (C) 2010 Elsevier B.V. All rights reserved.