Gold Nano-Particle Based Localized Plasmon Resonance Biosensors

Abstract

Noble metal nanoparticles exhibit localized surface plasmon resonances (LSPR) as a result of excitation by light, are used for label-free biosensing applications and bioimaging. Particularly, due to the high sensitivity of the nanoparticles to the change in local refractive index as a result of the interaction of the nanoparticles with biomolecules, molecular interactions that can be spectrally measured allow numerous studies on this subject. LSPR, used as an optical-based transduser in biosensors, depends on the size, shape and material properties of the metal nanoparticles. Single metal nanoparticles with large surface area and strong optical properties have unique chemical and physical properties compared to bulk metals. Nanoparticles can be synthesized in different forms such as nano-sphere, nano-rod, nano-wire, nano-cube with noble metals such as silver, copper and gold. Silver and gold are more preferred than copper because they are less reactive and more stable. Especially gold nanoparticles (AuNP) with higher conductivity and chemical stability are widely used in biotechnology. This review includes optical properties, synthesis techniques, plasmonic sensing methods and biosensor applications of commonly used nanosphere and nanorod AuNPs. Keywords: Localized surface plasmon resonance, gold nanoparticles, biosensors, affinity, conjugation, microscopy, spectroscopy, bioreceptor DOI: 10.7176/JSTR/5-12-21