Carbon Nanotubes for Electronic and Electrochemical Detection of Biomolecules

Abstract

The unique electronic and optical properties of carbon nanotubes, in conjunction with their size and mechanically robust nature, make these nanomaterials crucial to the development of next-generation biosensing platforms. In this Review, we present recent innovations in carbon nanotube-assisted biosensing technologies, such as DNA-hybridization, protein-binding, antibody-antigen and aptamers. Following a brief introduction on the diameter-and chirality-derived electronic characteristics of single-walled carbon nanotubes, the discussion is focused on the two major schemes for electronic biodetection, namely biotransistor-and electrochemistry-based sensors. Key fabrication methodologies are contrasted in light of device operation and performance, along with strategies for amplifying the signal while minimizing nonspecific binding. This Review is concluded with a perspective on future optimization based on array integration as well as exercising a better control in nanotube structure and biomolecular integration.

Penicillin biosensor based on a capacitive field-effect structure functionalized with a dendrimer/carbon nanotube multilayer

“…Carbon nanotubes (CNTs) are attractive for (bio-)chemical sensors because of their unique properties, which in most cases arise from the combination of electrical and chemical properties and nanosized dimensions (Balasubramanian and Burghard, 2006;Kim et al, 2007;Allen et al, 2007;Byon and Choi, 2006). One simple, versatile method to assemble dispersed CNTs is the layer-by-layer (LbL) technique, which offers fine control over film thickness and architecture (Hammond, 2004;Tang et al, 2006;Ariga et al, 2007), making it possible to combine different materials in a synergistic way (Jiang et al, 2004;Olek et al, 2004;Zucolotto et al, 2006;Siqueira et al, 2006Siqueira et al, , 2007Xue et al, 2006;Zucolotto et al, 2007).…”

Nanomaterials for Diagnosis: Challenges and Applications in Smart Devices Based on Molecular Recognition

“…Gao et al achieved sensitive and multicolor fluorescence imaging of cancer cells under in vivo conditions, with metastatic prostate cancer being detected as well. 96 The superior quality of QDs for 102 In single-walled carbon nanotubes (SWNTs), every atom is on the surface and therefore even small changes in the environment can cause drastic changes in their electrical properties. Their diameters are comparable to the size of single molecules (e.g., DNA is 1 nm in size), and they are several micrometers long, thereby providing a convenient interface with micrometer-scale circuitry.…”

“…With these features, NTFET devices are useful for detecting biological species. 102,106 Individual CNTs can also be used in electrochemical single devices, 108 leading to a fast, heterogeneous charge transfer. Electron beam lithography was used to expose a nanometer surface area, and the CNTs functioned as nanoelectrodes with an electrochemical current proportional to the exposed area, reaching 50 pA for a CNT length of 2 μm.…”

Carbon nanotubes as a novel drug delivery system for anticancer therapy: a review

“…Whether in the form of single-walled carbon nanotubes (SWCNTs) or multi-walled carbon nanotubes (MWCNTs), CNTs present several remarkable properties such as high aspect-ratio, ultra-light weight, tremendous strength, high thermal conductivity and significant electronic properties ranging from metallic to semiconducting (Ezzati et al, 2011;Lüer et al, 2009). CNTs may have different lengths ranging from several hundred nanometers to several millimeters, but their diameters depend on their class: SWCNTs are 0.4-3 nm in diameter and MWCNTs are 2-500 nm in diameter, depending on the method of synthesis (Kim et al,2007). MWCNTs also consist of several cylinders of graphitic shells with a spacing layer of 0.3-0.4 nm .…”