We report the fabrication of carbon nanotube field-effect transistors for biosensing applications and the development of protocols for reliable protein and DNA sensing. The sensing method we employ is 'label free', relying only on the intrinsic charge of the biological molecule of interest. We discuss fabrication issues that we have solved, for example the… (More)
Carbon nanotube transistors show tremendous potential for electronic detection of biomolecules in solution. However, the nature and magnitude of the sensing signal upon molecular adsorption have so far remained controversial. Here, the authors show that the choice of the reference electrode is critical and resolves much of the previous controversy. The… (More)
THz imaging and spectroscopy using broadband THz pulses map out the THz carrier dynamics of a large-area graphene-on-Si sample, showing that the local sheet-conductivity varies across the sample from σ<inf>s</inf>, = 1.7×10<sup>−3</sup> to 2.4×10<sup>−3</sup> Ω<sup>−1</sup>.
We demonstrate THz-induced transparency in two types of single-layer CVD graphene samples utilizing high-field THz pulses. The nonlinear THz transmission depends on the local conductivity of the samples and dynamically varies in the time domain.
Biosensor response time, which depends sensitively on the transport of biomolecules to the sensor surface, is a critical concern for future biosensor applications. We have fabricated carbon nanotube field-effect transistor biosensors and quantified protein binding rates onto these nanoelectronic sensors. Using this experimental platform we test the… (More)
Using THz spectroscopy, we obtained the resistivity of Ni-Ti alloy thin-films as a function of Ti concentration. The resistivity sharply increases near the phase transition boundaries, Ti concentrations of 22%, 44% and 62%.
It is well known that dipolar field effects lead to multiple spin echoes in a simple two-RF pulse experiment (the MSE experiment). We show here that coherence transfer echoes (which identify the existence of multiple quantum coherences in liquid NMR) and multiple spin echoes have a common origin. Using density matrix theory we have calculated the phase and… (More)