We report on synthesis of multifunctional composite nanofibers which can serve as active elements of (bio)sensors and microactuators. The nanofibers were made of cross-linked polymers by a template method. The method was used to prepare either suspensions or substrate-supported arrays of the nanofibers. Various functional nanoparticles (magnetic and fluorescent) were incorporated into the nanofibers. Magnetic nanoparticles, introduced inside the nanofibers, allowed for manipulations of the single nanofibers and actuation of the nanofibers' arrays with an external magnetic field. The composite nanofibers were surface-modified with polymers to control interactions between nanofibers and their environment. The surface of nanofibers was modified also with biomolecules to employ specific biorecognition mechanisms for applications in sensors.