S. Sorgenfrei, C.-Y. Chiu, C. Nuckolls, and K.L. Shepard, “Charge sensing using point-functionalized carbon-nanotube transistors for single-molecule detection,” Proc. of IEEE/NIH Life Science Systems and Applications Workshop 2011 (LiSSA ’11).

We have demonstrated that carbon-nanotube fieldeffect transistors act as highly sensitive single-molecule detectors when point functionalized. The hybridization kinetics of two complementary strands of DNA are associated with two-level fluctuations in the conductance of the nanotube to which the DNA is bound. We have studied the temperature dependence of the nanotube conductance and shown that the transport mechanism is consistent with Frenkel Poole emission, in which negatively charged DNA modulates a tunnel barrier at the point functionalized defect site. These transistors represent an important potential sensing platform for label-free single-molecule diagnostics.