Recent progress in nanotechnology has been significantly impacting a variety of areas such as utilization in microelectronics, multiphase catalysis, sensing and therapeutics. Our interests are to develop new nanomaterials to understand their structure-property relationships and to utilize them for various applications. In this thesis, we discuss our findings on the design, synthesis and applications of nanomaterials formed by self-assembly of amphiphilic molecules. Micelles are self-assembled nanostructures formed by amphiphilic molecules. They are capable of sequestering hydrophobic guest molecules in an aqueous environment. Other than surfactants, micelles can also be formed by amphiphilic polymers or dendrimers, which are macromolecular surfactants in a linear or branched fashion. We are interested in creating various functional materials based on self-assembled micelles that could be tuned by modifying the amphiphilic building blocks during their synthesis. We showed that utilizing the container property and dynamic equilibrium of small molecule surfactants, we were able to develop a protein nanosensor by non-covalently encapsulating a fluorophore-tethered ligand and a quencher in the micelle core. By incorporating an enzyme substrate on an amphiphilic dendrimer, we developed a nanoprobe that was capable of detecting enzyme activities based on 19F NMR spectroscopy. Last but not least, employing the convenience of polymer synthesis, we invented a new methodology of forming polymer nanoparticles by covalently crosslinking the hydrophobic components of micelles formed by amphiphilic random copolymers.