Composite Of Carbon Nanotube/Poly(3-Hexylthiophene) For Electrochemical Detection Of Metal Ions

In this study, multi-walled carbon nanotubes (MWNTs) were covalently modifiedby grafting poly(3-hexylthiophene)(P3HT) on their surfaces. The resultantMWNT-g-P3HT composite showed enhanced dispersibility in common solvent suchas THF. Due to the intimate interfaces between P3HT and MWNT, the modifiedMWNTs showed improved miscibility in P3HT matrix, leading to a tendency to formcontinuous MWNT-g-P3HT@P3HT composite films. Notably, theMWNT-g-P3HT@P3HT composite films were demonstrated enhanced sensitivity forquantitative detection of Hg2+ion due to the synergic effect of the electrocatalyticproperties from MWNTs and P3HT.In another part, we prepared electrochemically active films ofpoly(3-hexylthiophene) grafted single-walled carbon nanotubes (SWNT-g-P3HT) byusing a modified vacuum-assisted deposition approach, in which a SWNT-g-P3HTcomposite layer of various thicknesses was deposited on the top of a thin SWNT layer.Measurement of the optical and electrical properties of the SWNT-g-P3HT compositefilms demonstrated that preparation of the SWNT-g-P3HT composite films wascontrollable. The data of transmission electron microscope observation and Ramanspectroscopy indicated that the covalent grafting of P3HT onto the surfaces ofSWNTs resulted in intimate and stable connectivity between the two components inthe SWNT-g-P3HT composite. Capitalizing on these unique features, we successfullydeveloped a new class of electrochemical sensors that used the SWNT-g-P3HTcomposite films deposited on indium-tin oxide substrate as electrochemical electrodefor detection of metal ions. Significantly, such SWNT-g-P3HT composite electrodeshowed advantages in selective, quantitative, and more sensitive detection of Ag+ion.