Nanopore sensing is developing into a powerful label‐free approach to investigate the features of biomolecules at the single‐molecule level. When a charged molecule is captured within a nanopore, it modulates the ionic current, which can be recorded in real time to reveal the properties of the target molecule. To date, nanopores have been used to sense a variety of analytes, including DNA, RNA, proteins, enzymes, small molecules, cancer cells, and metal ions, and can also provide information on biomolecular structures. In this review, we highlight the progress made in nanopore sensing over the past five years (2016—2020), and provide an outlook on future developments and directions in the field

Nanopore technology has attracted extensive attention due to its rapid, highly sensitive, and label-free performance. In this study, we aimed to identify proteinogenic amino acids using a wild-type aerolysin nanopore....

i-Motifs are DNA secondary structures present in cytosine-rich sequences. These structures are formed in regulatory regions of the human genome and play key regulatory roles. The investigation of sequences capable of forming i-motif structures at the single-molecule level is highly important. In this study, we used α-hemolysin nanopores to systematically study a series of DNA sequences at the nanometer scale by providing structure-dependent signature current signals to gain in-sights into the i-motif DNA sequence and structural stability. Increasing the length of the cytosine tract in a range of 3− 10 nucleobases resulted in a longer translocation time through the pore, indicating improved stability. Changing the loop sequence and length in the sequences did not affect the formation of the i-motif structure but changed its stability. Importantly, the application of all-atom molecular dynamics simulations revealed the structural morphology of all sequences. Based on these results, we postulated a folding rule for i-motif formation, suggesting that thousands of cytosine-rich sequences in the human genome might fold into i-motif structures. Many of these were found in locations where structure formation is likely to play regulatory roles. These findings provide insights into the application of nanopores as a powerful tool for discovering potential i-motif-forming sequences and lay a foundation for future studies exploring the biological roles of i-motifs.