In this study, electrical charging phenomena in an organic memory structure using Au nanoparticles (NPs) conjugated with a specific binding mechanism were demonstrated. Monolayer of streptavidin-passivated Au NPs was incorporated on biotin-coated SiO(2) in structure of metal-pentacene-insulator-silicon (MPIS) device. Clockwise and counter-clockwise capacitance-voltage (C-V) hysteresis loops were measured depending on the oxide thickness. For 30 nm, a clockwise C-V hysteresis having memory window of 0.68 V was obtained under (+/-)12 V sweep range, while a counter-clockwise C-V hysteresis having memory window of 6.47 V was obtained under (+/-)7 V sweep range for 10 nm thick oxide. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3500824]