Carbon Nanomaterials in Biosensors: Should You Use Nanotubes or Graphene?

Abstract

From diagnosis of life-threatening diseases to detection of biological agents in warfare or terrorist attacks, biosensors are becoming a critical part of modern life. Many recent biosensors have incorporated carbon nanotubes as sensing elements, while a growing body of work has begun to do the same with the emergent nanomaterial graphene, which is effectively an unrolled nanotube. With this widespread use of carbon nanomaterials in biosensors, it is timely to assess how this trend is contributing to the science and applications of biosensors. This Review explores these issues by presenting the latest advances in electrochemical, electrical, and optical biosensors that use carbon nanotubes and graphene, and critically compares the performance of the two carbon allotropes in this application. Ultimately, carbon nanomaterials, although still to meet key challenges in fabrication and handling, have a bright future as biosensors.

Molecular Functionalization of Graphite Surfaces: Basal Plane versus Step Edge Electrochemical Activity

“…[1][2][3][4] Glassy carbon (GC), boron doped diamond and graphite have long received attention for electroanalytical and electrocatalytic measurements, [5][6][7][8][9][10][11] and, more recently, carbon nanotubes and graphene have generated considerable interest. [12][13][14][15][16][17] However, despite well-defined bulk properties and structure, carbon materials can possess rather complex surface chemistry that may substantially impact the resulting electrochemistry. 6 Indeed, the range of functional groups present at different carbon electrode/electrolyte interfaces is yet to be fully understood 9 and is significantly impacted by electrode preparation.…”

Molecular Beacon Lighting up on Graphene Oxide

“…carbon nanotubes and graphene oxide). [20][21][22][23][24][25][26] Graphene is a single layer of graphite with many superior electronic and mechanical properties. [27][28][29][30] By generating surface hydroxyl and carboxyl groups, the resulting graphene oxide (GO) can disperse in water.…”

Carbon nanomaterials field-effect-transistor-based biosensors

“…Examples of such nanomaterials include carbon nanotubes, 4-13 nanowires, 11,14-21 nanoparticles, 6,22-25 nanopores, 26,27 nanoclusters 28 and graphene. 5,[29][30][31][32] Compared with conventional optical, biochemical and biophysical methods, nanomaterial-based electronic biosensing offers significant advantages, such as high sensitivity and new sensing mechanisms, high spatial resolution for localized detection, facile integration with standard wafer-scale semiconductor processing and label-free, real-time detection in a nondestructive manner.Among diverse electrical biosensing architectures, devices based on field-effect transistors (FETs) have attracted great attention because they are an ideal biosensor that can directly translate the interactions between target biological molecules and the FET surface into readable electrical signals. [33][34][35][36][37][38] In a standard FET, current flows along a semiconductor path (the channel) that is connected to two electrodes, (the source and the drain).…”

“…Examples of such nanomaterials include carbon nanotubes, 4-13 nanowires, 11,14-21 nanoparticles, 6,22-25 nanopores, 26,27 nanoclusters 28 and graphene. 5,[29][30][31][32] Compared with conventional optical, biochemical and biophysical methods, nanomaterial-based electronic biosensing offers significant advantages, such as high sensitivity and new sensing mechanisms, high spatial resolution for localized detection, facile integration with standard wafer-scale semiconductor processing and label-free, real-time detection in a nondestructive manner.…”