Fig. 2.

Strategies for CTC enrichment. a A fiber mat of electrospun nylon-6/PEO fibre for CTCs capture; b A ZnO nanowire coated polydimethylsiloxane pillar substrate with a gear structure; c Tumor-targeting molecule folic acid (FA) and magnetic nanoparticles (MNPs) coated engineered red blood cells (RBCs); d A microfluidic device integrated of dendrimer-mediated multivalent binding, a mixture of antibodies, and biomimetic cell rolling; e An ensemble-decision aliquot ranking (eDAR) microfluidic device using sequential sorting and flow stretching. a Copyright Springer Nature 2018. Reproduced with permission from reference [24]; b Copyright RSC Publishing 2020. Reproduced with permission from reference [25]; c Copyright RSC Publishing 2018. Reproduced with permission from reference [26]; d Copyright Elsevier 2020. Reproduced with permission from reference [40]; e Copyright American Chemical Society 2019. Reproduced with permission from reference [61]