A novel flexible carbon nanotube/silver nanowire electrode toward trace Cu(II) detection in water

In this study, a nitrogen-doped multi-walled carbon nanotube (N-MWCNTs)/silver nanowire (AgNWs) nanocomposite electrode was prepared, using polydimethylsiloxane (PDMS) as a flexible substrate and N-MWCNTs and AgNWs as conductive materials. Trace Cu(II) in water was monitored by square wave stripping voltammetry (SWSV). Compared with commercial electrodes, the N-MWCNTs/AgNWs composite electrode generated much higher responsive peak current in detecting Cu(II), due to the enhanced conductivity of the composite electrode and the strong complexing ability of the N-MWCNTs for Cu(II). In the SWSV, this new electrode showed 0.06 μg/L (S/N = 3) limit of detection, a linear range from 0.500 to 100 μg/L, high resistance to interfering metals such as Ca(II), K(I), Zn(II), Na(I), Al(III), Fe(III), Hg(II), Cr(VI), Bi(III), Sb(III) and Sn(II), and stable response in natural water samples without sample pretreatment. This study established a new method for facile fabrication of high-performance flexible Cu(II) sensor with N-MWCNTs and AgNWs.