Investigation of gold nanorod monomer biosensors for label free molecule detection

Abstract

Plasmon resonances have attracted a lot of recent research interest for their potential applications, including bio-sensing, sub-wavelength optics, negative refractive index metamaterials and their ability to produce massively enhanced electromagnetic fields. Localized surface plasmon resonances (LSPR) in metallic nanostructure can offer large electromagnetic enhancements and nanometer-scale localization of electric fields. Their resonance wavelength and properties can be tuned by variation of the nanostructure geometry and are sensitive to environmental refractive index. This thesis contains in depth investigation of gold nanorod monomer biosensors for label free molecule detection. Some core plasmonic properties of gold and its importance in LSPR sensing are analyzed. In addition, LSPR shifts are closely observed by varying different physical parameters of the biosensor structure. Furthermore, we closely observed the LSPR response by changing the physical environment of the biosensor structure by tuning corresponding refractive indices. Finally, we explored the responsible factors for the sensitivity of bio-proteins and compared our results with theory.