Tuning the functional interface of carbon nanotubes by electrochemistry: Toward nanoscale chemical sensors and biosensors

The ability to tune the functional interface of single-walled carbon nanotubes in a versatile manner is key to the success of deploying them as an active material in chemical and biological sensors. Here we present an overview of our device strategies demonstrating the use of controlled electrochemical functionalization to tune this interface by bringing in different functionalities ranging from metallic nanoparticles to biomolecules onto the nanotube surface. The extent of such a functionalization is tunable, providing us with a good control over sensitivity, selectivity, and detection limit of the realized sensors. Moreover, the sensor mechanisms have been analyzed. Taken together the methods and results outlined here constitute a general framework for the rational design of nanoscale field-effect-based chemical sensors and biosensors.