Circulating tumor cells (CTCs) have been believed to hold significant insights for cancer diagnosis and therapy. Here, we developed a simple and effective method to capture and release viable CTCs using core-shell Fe3O4@MnO2 nanoparticles. Fe3O4@MnO2 nanoparticles bioconjugated with anti-EpCAM antibody have characteristics of specific recognition, magnetic-driven cell isolation and oxalic acid-assisted cell release. The capture and release efficiency of target cancer cells were similar to 83% and similar to 55%, respectively. And similar to 70% of released cells kept good viability, which could facilitate the subsequent cellular analysis. (C) 2016 Elsevier B.V. All rights reserved.