Single electron charge sensitivity of liquid-gated carbon nanotube transistors.

Random telegraph signals corresponding to activated charge traps were observed with liquid-gated CNT FETs. The high signal-to-noise ratio that we observe demonstrates that single electron charge sensing is possible with CNT FETs in liquids at room temperature. We have characterized the gate-voltage dependence of the random telegraph signals and compared to theoretical predictions. The gate-voltage dependence clearly identifies the sign of the activated trapped charge.