Nanopore detects γ-radiation inhibited HIV-1 protease activity

Aerolysin nanopore-based identification of proteinogenic amino acids using a bipolar peptide probe

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. Specifically, bipolar peptide probes were synthesised by linking four aspartic acid residues to the N-terminal and five arginine residues to the C-terminal of individual amino acids. With the help of the bipolar peptide carrier, 9 proteinogenic amino acids were reliably recognised based on current blockade and dwell time using an aerolysin nanopore. Furthermore, by changing the charge of the peptide probe, two of the five unrecognized amino acids above mentioned were identified. These findings promoted the application of aerolysin nanopores in proteinogenic amino acid recognition.

Label-free Sensing of Main Protease Activity of SARS-CoV-2 with an Aerolysin Nanopore

The main protease (M pro ), which is highly conserved and plays a critical role in the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a natural biomarker for SARS-CoV-2. Accurate assessment of the M pro activity is crucial for the detection of SARS-CoV-2. Herein, we report a nanopore-based sensing strategy that uses an enzyme-catalyzed cleavage reaction of a peptide substrate to measure the M pro  activity. The peptide was specifically cleaved by the M pro , thereby releasing the output products that, when translocated through aerolysin, quantitatively produced the signature current events. The proposed method exhibited high sensitivity, allowing the detection of M pro concentrations as low as 1 nM without the use of any signal amplification techniques. This simple, convenient, and label-free nanopore assay may expand the diagnostic tools for viruses.

Chemistry solutions to facilitate nanopore detection and analysis

Characteristic ionic current modulations will be produced in a single molecule manner during the communication of individual molecules with a nanopore. Hence, the information regarding the length, composition, and structure of a molecule can be extracted from deciphering the electrical message. However, until now, achieving a satisfactory resolution for observation and quantification of a target analyte in a complex system remains a nontrivial task. In this review, we summarize the progress and especially the recent advance in utilizing chemistry solutions to facilitate nanopore detection and analysis. The discussed chemistry solutions are classified into several major categories, including covalent/non-covalent chemistry, redox chemistry, displacement chemistry, back titration chemistry, chelation chemistry, hydrolysis-chemistry, and click chemistry. Considering the significant success of using chemical reaction-assisted nanopore sensing strategies to improve sensor sensitivity & selectivity and to study various topics, other non-chemistry based methodologies can undoubtedly be employed by nanopore sensors to explore new applications in the interdisciplinary area of chemistry, biology, materials, and nanotechnology.