The talk will focus on metal and metal oxide nanoparticles. A one-phase synthesis of thiolate-functionalized metallic nanoparticles will be described, and further chemical reactions, such as surface-initiated polymerization and attachment of DNA bases will be presented. Sonochemical preparation of oxide and mixed oxide nanoparticles will be reported. We have demonstrated, for the first time, that sonication is a very efficient method for coating of @gamma@-Fe@sub 2@O@sub 3@ and other oxide nanoparticles. The attachment of enzymes to @gamma@-Fe@sub 2@O@sub 3@ nanoparticles will be described.