Two- and three-dimensional, ordered nanocrystal arrays are formed from the self-assembly of water-soluble nanocrystal-micelles that are prepared using surfactant encapsulation techniques. This new method is simple, widely applicable, and can be used to prepare water-soluble nanocrystals with different compositions and shapes, such as sphere, rod, and cube, as well as their ordered arrays (see Figure). Applications in fabrication of SERS-based sensor platforms are envisaged.