This paper is intended to demonstrate the effect of coupled long-range surface plasmon polaritons (LRSPPs) on the optical response of a lamellar grating nanostructure with organic material on the surface. This phenomenon gives rise to a selective spectral response and a local field enhancement which can be used in the context of nano-optics. This novel structure of nanofabricated device, consisting of coupled organic/metal nanostructure with specific width and symmetric dielectric structure. By designing the size and shape of the grating nanostructure, and the location of the organic Alq3 relative to the surfaces, Alq3 can be quenched, display increases in emission quantum yield, and decreasing the lifetimes. The combinations of organic/metal interface LRSPP mode can emit specific direction rather than isotropic emission. We discuss recent experimental results and potential applications in biosensor, organic light emitting diodes (OLEDs), polymer laser and organic solar cells of organic/metal grating enhanced emission resonance energy interactions.