(655b) Controlled Assembly and Disassembly of Biotinylated Au Nanopatricles on Metallic Nanowires for Nanobiosensing

The reversible binding of biotin capped Au nanoparticles to the streptavidin coated surfaces can be useful for nano-electronic and nano-sensor applications. Au nanoparticles derivitized with ethylene glycol and biotin together exhibit reversible aggregation characteristics. Streptavidin functionalized metallic nanowires were electrofluidically aligned between micron-size separated planar electrodes under an AC bias and were interacted with the biotinylated Au nanoparticles dispersed in water. The biotinylated nanospheres were assembled on the nanowire surface because of the biorecognition and disassociated by adding free biotin, removing the Au nanoparticles from the surface.

The current electrical nanobiosensing platforms based on FET, conductance measurements of single molecules and molecular electronics applications suffer from the stability and reproducibility and scaling due to the local environment of the molecules being characterized, interaction with vibrational modes and microscopic coupling of the molecule to the measurement electrodes. For this reason, electrical measurements undergo large variations and drawing a good conclusion about the conductance of molecules necessitates averaging of multiple measurements. Nanoparticle based reversible binding of an analyte or a single molecule approach can be used to validate the electrical response of the nanobiosensor and molecular electronics systems.