Circulating Tumor Cells (CTCs) and Circulating Tumor Microemboli (CTM), CTC clusters, are rare cell species present in peripheral blood and appear in circulatory system during cancer metastasis. Phenotypes of single or aggregated CTCs can be different and may present differ-ent levels of potential aggressiveness. In order to track metastasis and achieve early-stage di-agnosis, detection and capturing both of CTCs and CTM are crucial. However, due to their extremely low abundance, identifying CTCs and CTM in blood samples is challenging. Cur-rently, detection of these cells mainly accomplished by labeling method based on cancer cells’ surface markers, or by non-labeling microfluidic devices which classify cells by their physical properties such as density and size. 

Our research presents a non-invasive, real-time observable microfluidic diagnosis system aim-ing at highly sensitive capturing of CTCs and CTMs, and the detection of their exosome and ctDNA. Specific antibodies are able to recognize surface markers, such as EpCAM, on tumor cells. The chosen antibodies are immobilized on the inner surface of graphene oxide-functionalized PDMS micro-channel through click chemistry, in which graphene oxide is used as a bio-nano interface to enhance antibodies conjugation in this system due to its numerous functional groups and high biocompatibility. Moreover, to maximize the interaction between CTCs and antibody-coated surfaces, the channel is extremely thin with large surface area and specific types of cancer cells are able to be captured by the corresponding antibodies. Hence, CTCs and CTMs are expected to be detected and captured at early stage. This allows early prediction of metastasis and thus assist in selecting effective treatment for each patient.