Nanopore Stochastic Sensing Based on Non-covalent Interactions.

A variety of species could be detected by using nanopores engineered with various recognition sites based upon non-covalent interactions, including electrostatic, aromatic, and hydrophobic interactions. The existence of these engineered non-covalent bonding sites was supported by the single-channel recording technique. The advantage of the non-covalent interaction-based sensing strategy was that the recognition site of the engineered nanopore was not specific for a particular molecule but instead selective for a class of species (e.g., cationic, anionic, aromatic, and hydrophobic). Since different species produce current modulations with quite different signatures represented by amplitude, residence time, and even characteristic voltage-dependence curve, the non-covalent interaction-based nanopore sensor could not only differentiate individual molecules in the same category but also enable differentiation between species with similar structures or molecular weights. Hence, our developed non-covalent interaction-based nanopore sensing strategy may find useful application in the detection of molecules of medical and/or environmental importance.