DNA Sensing by Field-Effect Transistors Based on Networks of Carbon Nanotubes

Abstract

We report on the sensing mechanism of electrical detection of deoxyribonucleic acid (DNA) hybridization for Au- and Cr-contacted field effect transistors based on single-walled carbon nanotube (SWCNT) networks. Barrier height extraction via low-temperature electrical measurement provides direct evidence for the notion that the energy level alignment between electrode and SWCNTs can be affected by DNA immobilization and hybridization. The study of location-selective capping using photoresist provides comprehensive evidence that the sensing of DNA is dominated by the change in metal-SWCNT junctions rather than the channel conductance.

Endohedral confinement of a DNA dodecamer onto pristine carbon nanotubes and the stability of the canonical B form

“…While structure in its natural form and environment is well established (e.g. B-DNA in aqueous solution), their interactions have been the subject of intense investigation 4,5,8,[10][11][12][13][14][15][16] , nonetheless, the corresponding molecular-level phenomena remain rather unexplored. Is confinement thermodynamically spontaneous (free-energy)?…”

Carbon nanomaterials field-effect-transistor-based biosensors

“…[46][47][48][49] In the case of solution-gate FETs, the modulation of the channel conductance is achieved by applying a gate potential at the solid/ liquid interface from a reference electrode placed on top of the channel across the electrolyte that acts as the dielectric. The conductance of SWNTs and graphene shows the strong dependence on the ionic strength, the pH and the type of ions present.…”

Dispersions Based on Carbon Nanotubes – Biomolecules Conjugates

“…The sensitivity of the DNA sensor was 0.06 mV/nM. The conductance modulation of these sensors can be explained based on the mechanism which has been well studied in literature [65]. The mechanism for electrical detection of the DNA hybridization in semiconducting carbon nanotube network devices in this work was likely due to the modification of junction barrier energy, whereas the conductance change forming the metal-nanotube's contact by efficient hybridization on the Pt electrodes was the dominant sensing mechanism.…”

“…Although an appreciable amount of biosensing studies has been conducted using carbon nanotube transistors, the physical mechanism that underlies sensing is still under debate [61]. Some mechanisms of biosensing are electrostatic gating [65], changes in gate coupling [66], carrier mobility changes [63] and Schottky barrier effects [67]. Tama et al have developed a DNA sensor based on multi-walled carbon nanotubes (MWCNTs) [68].…”