Carbon Nanotube-Based Biosensors

Abstract

Carbon nanotubes (CNTs) have been widely employed as the key components in various biosensors due to their unique properties, such as very large surface to volume ratio, high sensitivity to their surface adsorbates, and good compatibility with most chemical and biological compounds. In this chapter, the electrocatalytic properties of CNTs followed by the functionalization of CNTs and the construction of CNT-modified electrodes will be discussed. Furthermore, we will focus on recent advances in CNT-based electrochemical biosensors. 11.1 IntroductionCarbon nanotubes (CNTs) have been captivating researchers in a great variety of scientific fields since the tremendously impacted Nature paper about "helical microtubules of graphitic carbon" published by Dr. Sumio Iijima in 1991 [1]. Interestingly, the first possible observation of multi-wall carbon nanotubes (MWCNTs)was documented in 1952 followed by a huge amount of recurrent investigations into the nanometer-scale carbon filaments before the well-known "discovery" of MWCNTs in 1991 [2]. Nevertheless, it was undoubtedly true that the occurrence of CNTs in 1991 exceedingly advanced the perception of nanometer-scale materials and extensively stimulated the research interest in CNTs. In 1992, Ebbesen and Ajayan developed the method for mass production of CNTs by arc-discharge technique [3], which effectively narrowed the gap between demand and supply. In 1993, single-wall carbon nanotubes (SWCNTs) were first synthesized in the vapor phase by the catalysis of iron [4] or cobalt [5], which convincingly enriched the conception of CNTs. Since then, the exploration of CNTs reached at an unprecedented level and quickly superseded fullerene as the hottest subject of carbon materials (Figure 11.1).