A novel theoretical approach is developed for treating energy transfer interactions between a donor and an acceptor molecule in the proximity of a nanoshell. Motivated from the diverse applications and rich plasmonic features of plasmonic nanoshell for example, tuning capability of Surface Plasmon (SP) frequencies, greater sensitivity to the dielectric environment, and controllable redirection of EM radiation, closed form expressions are derived for the amplification factor of nanoshell mediated intermolecular energy transfer. Closed form expressions derived in this manuscript can directly be used as formula for; designing SP based biosensors, calculating energy exchange between proteins and excitonic interactions in Quantum Dots (QDs).