The metastatic tumor cells, namely, circulating tumor cells (CTCs), can be considered as a “liquid biopsy” of the primary and disseminated tumors, which provide a promising alternative for early diagnosis of metastases, cancer prognosis, and personalized therapy. This chapter summarizes the recent progress of 3D nanostructured substrates as a promising platform for CTCs detection, which are assembled from many low-dimensional building blocks such as nanoparticles, nanofractals, nanowires, nanoposts/pillars, nanotubes, and nanofibers, as well as nanopores. The cell-capture capability can be greatly enhanced through the topographic interaction between nanostructured substrates and surface components of target cells. In addition, the recognition molecules and responsive molecules bring in the specificity and responsiveness of nanostructured substrates for cells that make the substrates capture only target cells and face complicated external environments. More interestingly, some nanostructured substrates have been successfully used for isolation and detection of other cells, greatly expanding the significance of CTC-related research. Soft Matter Nanotechnology , 2015 |