Zeptogram scale mass sensing using single walled carbon nanotube based biosensors

During recent years carbon nanotubes are being increasingly used for mass sensing. This study investigates single walled carbon nanotubes as the sensing devices for biological objects. An expression has been formulated to detect the mass of biological objects from the shift of frequency. The application of a carbon nanotube for zeptogram-level mass detection has been explored. Molecular structural mechanics approach has been used for investigating the dynamic responses of chiral single walled carbon nanotube based nano biosensors. The nanotube is considered as a space frame structure. The beam element properties are calculated by considering mechanical characteristics of covalent bonds between the carbon atoms in the hexagonal lattice. The mass of each beam element is assumed as point masses at nodes coinciding with carbon atoms. The results suggest that a single walled carbon nanotube is a promising candidate for a bio-molecular nano sensor with the sensitivity reaching to an order of 0.12 Zg/GHz.