The near-field contrast formation in spherical nanoparticles and bowtie shaped metallic nanostructures is investigated using apertureless near-field scanning optical microscopy (ANSOM). Field enhancement due to plasmon resonance is explored of gold nanospheres prepared via drop-casting and plasmonic nanoantennas prepared via high resolution electron beam lithography. Specifically, the fundamental properties of localized surface plasmon resonance (LSPR) due to variably-sized gold nanospheres and gold bowtie nanoantennas under varied polarization angles are examined. These experimental results are compared to theoretical model calculations based on an extended dipole model and finite-difference time-domain (FDTD) simulations [1] for the absorption and scattering of a nanoparticle and bowtie nanoantenna at or near plasmon resonance. Near-field measurements of signal enhancement due to LSPR were taken and analyzed.