Nanosphere structure are the suitable and efficient nanoparticle for the biological application in designing the refractive index-based sensors. Modeling and analysis of Nanosphere structure is simulated. Nanosphere structure acts as a surface plasmon device. The Gold nanospheres are commonly used nano devices. The UV visible spectrum wavelength from 300nm-900nm is applied. The Mie scattering algorithm and dipole approximation methods are the modeling methods used. The cross-section efficiency and sensitivity of the nanosphere based refractive index sensor is analyzed. The mathematical analysis is conducted using discrete dipole approximation method. These are the part of the theory of scattering of light by nano particles which has homogenous and spherical in size. The Riccati-Bessel functions are used in the Mie calculations.