Single molecule detection and macromolecular weighting using an all-carbon-nanotube nanoelectromechanical sensor

In this study, we propose and simulate a high-sensitivity carbon nanotube sensor, capable of transducing protein-ligand binding, or more generally, macromolecular-recognition into a frequency variation of an electric current. In conjunction with small proteins like streptavidin the nanosensor can reach the sensitivity threshold, i.e. detecting a single molecule binding. For heavier, virus-sized particles the same device can provide a relatively accurate measure of their mass. In a first step, we focus on mechanical issues and characterize the sensor under several aspects both by molecular dynamics and continuous shell theory. The second part focuses on the transduction of the cantilever deflection into an electrical signal, and is achieved through a combination of Green´s functions and spatial domain decomposition. The influence of thermal effects on the proper operation of the sensor is also discussed in conjunction with the construction of the current-displacement characteristic.