Nanopore sensors (nanopore and nanopippette) can be used to nondestructively real-time detect secretions from single cells. With proper design and micro/nanoscale manipulation, we are allowed to detect certain significant biomarkers by positioning a nanopore next to a cell. Otherwise these biomarkers could easily be too diluted as soon as secreted to cellular ambience. For example, a nanopore sensor may detect secreted chemokine CCL5 from a cancer cell so that it can be employed to estimate disease progression. Since the topography and dimensions of a nanopore can be precisely adjusted during fabrication, one can selectively detect targeted molecules according to their sizes. Furthermore, once more than 20 secreted molecules are detected from a cell, we can differentiate this cell from one among different types in a fast real-time way.

Figure 1. Nanopore (~6.4 nm²) with optical tweezers detected CCL5 secreted from a U-937 cell.

E. Kennedy*, M. Hokmabadi*, Z. Dong et al., Nano Letters, 2018.