A carbon nanotube sensor and a method of producing the carbon nanotube sensor are disclosed. The sensor detects small particles and molecules. The sensor includes a gate, a source and a drain positioned on the gate, and a carbon nanotube grown from a catalytic material and extending from one of the source and the drain. The method includes the step of functionalizing an end of the carbon nanotube with a receptor. As such, the carbon nanotube is receptive to the small particles and molecules. The carbon nanotube is driven at a resonance, and the resonance of the carbon nanotube is measured when the end of the carbon nanotube is free of the small particles and the molecules. The method includes monitoring for a change in the resonance to detect the association of the small particles and molecules with the end of the carbon nanotube.