Carbon nanotubes-functionalized urchin-like In2S3 nanostructure for sensitive and selective electrochemical sensing of dopamine

Urchin-like In2S3 nanostructures were functionalized with multi-walled carbon nanotubes (MWCNTs) and deposited on a glassy carbon electrode (GCE) to obtain a new kind of sensor for dopamine (DA). The new electrode was characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, cyclic voltammetry and differential pulse voltammetry. It is found that the current response toward DA is significantly enhanced compared to that of a bare GCE or a GCE modified with MWCNTs. The peak separation between DA and ascorbic acid (AA) is up to 225 mV. The new electrode also has improved selectivity for DA over AA compared to the bare electrode. The new DA sensor has a wide linear range (0.5-300 mu M), high sensitivity (594.9 mu A mM(-1) cm(-2)) and low detection limit (0.1 mu M). CNTs wrapped on urchin-like nanostructures remarkable improve its electrocatalytic activity and thus provide a promising strategy to develop excellent composite materials for electrochemical sensing.