Preparation of a shared chip for cell capturing and imaging with nanoparticle scaffold, nanogap and circulating tumor cell detection supplementary information

Aim: To achieve accurate detection of circulating tumor cells (CTCs) in a large-volume sample. Materials &
methods: Silica nanoparticles were crosslinked layer-by-layer on glass slides as the substrate of a chip using
polyacrylic acid. Polyacrylic acid was immobilized as a spacer and capture ligands were immobilized on the
spacer. Results: The chip can be integrally applied to capture, post-treatment and imaging detection for
CTCs. The detected cell numbers were 33 and 40 for 9 cell/ml samples and clinical blood samples (7.5 ml),
respectively. The detection ratio of positive samples was 100%. Conclusion: The significantly increased
detected number for CTCs indicates that this methodology may avoid or greatly reduce the false-negative
ratio of positive clinical samples.