Pentacene films were deposited on a silica surface decorated with gold nanoparticles (Au-NPs). The crystallinity and packing orientation of the film are critically dependent on the surface properties of the nanoparticles, which can be tuned by a self-assembled monolayer (SAM) of organic thiolate on the nanoparticles. High-performance field-effect transistors based on the Au-NPs-embedded pentacene films can be prepared if the nanoparticles are made "hydrophobic" as well as "oleophobic" by appropriate SAMs. Electrical bistability was observed in these devices, with a memory window that depends on the size and surface modification of the Au-NPs. The structural characterization and electronic characteristics of the devices will be detailed.