The principle of the Transmission Plasmon Biosensor is based on LSPR of metal nanoparticles attached to a transparent substrate. When the analyte of interest binds to the bioreceptors immobilized onto these nanoparticles, the absorption properties will change. This type of nanobiosensors has several advantages since they are easy to fabricate, simple to implement and they only require a spectrophotometer. Importantly, the sensor can be easily multiplexed in an array format. In this study, we optimized various parameters in order to increase the sensitivity of these devices. Since the LSPR of the immobilized nanoparticles and thus the sensitivity of the biosensor depends on the size, the shape, the material and the (bio)functionality of the nanoparticles, much effort has been put in the tuning of the nanoparticles. Besides spherical gold and silver particles, we synthesized nanoparticles with various shape, but also core-shell nanoparticles. In addition, we developed three-dimensional substrates using assemblies of nanoparticles. For biosensing applications, the nanoparticles need to be functionalized with a surface chemistry that allows attachment of bioreceptors. In this study, mixed SAMs were used to couple conventional antibody(fragments) and small molecules to the nanoparticles. The change in absorption of the nanoparticle films upon antibody-antigen binding is monitored.
Journal: TechConnect Briefs
Volume: 2, Technical Proceedings of the 2007 NSTI Nanotechnology Conference and Trade Show, Volume 2
Published: May 20, 2007
Pages: 579 - 582
Industry sector: Sensors, MEMS, Electronics
Topics: Biomaterials, Chemical, Physical & Bio-Sensors