Real-time identification of multiple nanoclusters with a protein nanopore in single-cluster level

It is important and challenging to analyze nanocluster structure with atomic precision. Herein, a-hemolysin nanopore was used to identify nanoclusters at the single molecule level by providing two-dimensional (2D) dwell time-current blockage spectra and translocation event frequency which sensitively depended on their structures. Nanoclusters such as Anderson, Keggin, Dawson, and a few lacunary Dawson polyoxometalates with very similar structures, even with only a two-atom difference, could be discriminated. This nanopore device could simultaneously measure multiple nanoclusters in a mixture qualitatively and quantitatively. Furthermore, molecular dynamics (MD) simulations provided microscopic understandings of the nanocluster translocation dynamics and yielded 2D dwell time-current blockage spectra in close agreement with experiments. The nanopore platform provides a novel powerful tool for nanocluster characterization.