Effective and selective cell retention and recovery from whole blood by electroactive thin films.

Hematogenous metastatic spread causes most cancer patient deaths. Because circulating tumor cells (CTCs) are highly relevant to early metastatic spread, the capture or detection of these cells provides a diagnostic tool for patients with metastatic conditions. Herein, we demonstrate a programmable electroactive multilayered material platform with a smart electrically induced "switch" that captures CTCs from biological plasma with high efficiency and releases the captured cells flexibly. The released cells are still viable and proliferative, which facilitates the detection of trace levels of CTCs by amplification. Furthermore, the inherent rough characteristics of the nanoparticle-composed interface can promote capture efficiency and cell purification by integration with a simple microfluidic device. This elegant, inexpensive, and versatile platform for cell sorting and enrichment makes subsequent molecular and cell biological analysis achievable. The strategy has broad implications for favoring fundamental cancer biology research, for the diagnosis and monitoring of cancer individually, and for advanced intervention based on blood purification.