347— Nano-scale Description through Dynamical Investigation of Adsorption Orientation

The energy loss of dye-embedded amyloid beta peptide 1-40 (Ab1-40; fluorescein-attached amyloid beta 1-40, FAb) was examined with various sizes of gold nano-colloidal particles. The fluorescence profile implied which segment of Ab1-40 was used for the adsorption. The entire dynamical profile of fluorescein was successfully explained by a relative degree of interaction between a fluorescein and the gold nano-particle surface. The FAb was utilized to create a hydrophilic-charge interaction at the nano-scale interface of FAb and gold nano-particle under DMSO (dimethyl sulfoxide) environment. In this case, we hypothesize that the FAb adsorbed over the nano-colloidal surface through the hydrophilic (N-terminal side) segments. Since the entire dynamical profile of fluorescein can be understood as a relative degree of interaction between a fluorescein and the gold nano-particle surface, observed quenching features must imply that fluorescein attached side (C-terminal) is very closely located to the nano-gold colloidal surface.