Single‐Molecule Binding Assay Using Nanopores and Dimeric NP Conjugates

• Published in: Advanced materials (Weinheim) 2021-09, Vol.33 (38), p.e2103067-n/a
• Main Authors: Ren, Ren, Sun, Maozhong, Goel, Pratibha, Cai, Shenglin, Kotov, Nicholas A., Kuang, Hua, Xu, Chuanlai, Ivanov, Aleksandar P., Edel, Joshua B.
• Format: Article
• Language: English
• Subjects: Antibodies; Antigens; Binding; Biomarkers; Biosensing Techniques - methods; Diagnosis; diagnostics; Dimerization; Humans; Materials science; MicroRNAs; MicroRNAs - analysis; MicroRNAs - metabolism; molecular probes; Nanoparticles; Nanoparticles - chemistry; nanopore sensing; Nanopores; Ribonucleic acid; RNA; Screening; Selectivity; self‐assembly; Single Molecule Imaging - methods; single‐molecule detection
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202103067

The ability to measure biomarkers, both specifically and selectively at the single‐molecule level in biological fluids, has the potential to transform the diagnosis, monitoring, and therapeutic intervention of diseases. The use of nanopores has been gaining prominence in this area, not only for sequencing but more recently in screening applications. The selectivity of nanopore sensing can be substantially improved with the use of labels, but substantial challenges remain, especially when trying to differentiate between bound from unbound targets. Here highly sensitive and selective molecular probes made from nanoparticles (NPs) that self‐assemble and dimerize upon binding to a biological target are designed. It is shown that both single and paired NPs can be successfully resolved and detected at the single‐molecule nanopore sensing and can be used for applications such as antigen/antibody detection and microRNA (miRNA) sequence analysis. It is expected that such technology will contribute significantly to developing highly sensitive and selective strategies for the diagnosis and screening of diseases without the need for sample processing or amplification while requiring minimal sample volume. A single‐molecule nanopore‐based sensing strategy is developed to screen for biomarkers. In the presence of the target biomolecules, AuNPs dimerize and are detected electrically using a nanopore. This approach is highly sensitive and selective and can potentially be used for diagnosis and screening of diseases without the need for sample processing or amplification.