Integrated Multifunctional Electrochemistry Microchip for Highly Efficient Capture, Release, Lysis, and Analysis of Circulating Tumor Cells

The circulating tumor cells (CTCs) in the blood allow the noninvasive analysis of metastatic mechanisms, cancer diagnosis, prognosis, disease monitoring, and precise therapy through "liquid biopsies". However, there is no integrated and robust multifunctional microchip, which not only could highly efficient capture CTCs, but also fast release and lyse cells on one single chip without using other biochemical agents for downstream biomedical analysis. In this work, we integrated the three functions in one electrochemical microchip (echip) by intentionally designing a cactus-like, topologically structured conductive array consisted of a PDMS micropillar-array core and an electro-conductive gold coating layer with hierarchical structure. The echip presented a capture efficiency of 85-100% for different cell lines in both buffer solution and whole blood. Moreover, the validity of the echip was further evaluated by using non-small-cell lung cancer patient samples. The electrochemical released cells or lysed-cell solutions could be obtained within 10 min and have been successfully used for mutant detection by DNA sequencing or RT-PCR. The fast release at a relative low voltage (-1.2 V) was originating from an electrochemical cleavage of the Au-S bonds that immobilized antibody on the chip. The electrochemical lysis took place at a high voltage (20 V) with an admirable performance. Thus, the highly integrated multifunctional echip was well demonstrated and promised a significant application in the clinical field.