Nanomaterials have been widely used in many products due to their unique properties. When nanomaterials are released to environmental systems during production, usage and disposal processes, ionization to heavy metal ions are major problem. The effects of heavy metal ions to human have been researched over many years and potential risk of heavy metal ions are reported. In this work, we are focused on silver ion which is one of the important heavy metal ion and develop an ultra-sensitive silver ion detection techniques using micro resonator and gold nanoparticles. The detection technique is based on the resonance frequency shift of micro resonator upon adsorption of silver ions and gold nanoparticles. By using gold nanoparticles, mass amplification is achieved and therefore, the detection performance is highly increased.