Composite\nFilms of Poly(3-hexylthiophene) Grafted Single-Walled Carbon Nanotubes\nfor Electrochemical Detection of Metal Ions

Abstract

In this study, we prepared electrochemically\nactive films of poly­(3-hexylthiophene) grafted single-walled carbon\nnanotubes (SWNT-g-P3HT) by using a modified vacuum-assisted deposition\napproach, in which a SWNT-g-P3HT composite layer of various thicknesses\nwas deposited on the top of a thin SWNT layer. Measurement of the\noptical and electrical properties of the SWNT-g-P3HT composite films\ndemonstrated that the thickness of the SWNT-g-P3HT composite films\nwas controllable. The data of transmission electron microscope observation\nand Raman spectroscopy indicated that the covalent grafting of P3HT\nonto the surfaces of SWNTs resulted in intimate and stable connectivity\nbetween the two components in the SWNT-g-P3HT composite. Capitalizing\non these unique features, we successfully developed a new class of\nelectrochemical sensors that used the SWNT-g-P3HT composite films\ndeposited on an indium–tin oxide substrate as an electrochemical\nelectrode for detection of metal ions. Significantly, such a SWNT-g-P3HT\ncomposite electrode showed advantages in selective, quantitative,\nand more sensitive detection of Ag⁺ ions.