Rapid and reliable detection of ultralow-abundance nucleic acids and proteins in complex biological media may greatly advance clinical diagnostics and biotechnology development. Currently, nucleic acid tests rely on enzymatic processes for target amplification (e.g. polymerase chain reaction), which have many inherent issues restricting their implementation in diagnostics. On the other hand, there exist no protein amplification techniques, greatly limiting the development of protein-based diagnosis. We report a universal biomolecule enrichment technique termed HOLMES (Hierarchical NanOfLuidic Molecular Enrichment System) for amplification-free molecular diagnostics using massively paralleled and hierarchically cascaded nanofluidic concentrators. HOLMES achieves billion-fold enrichment of both nucleic acids and proteins within 30 min, which not only overcomes many inherent issues of nucleic acid amplification, but also provides unprecedented enrichment performance for protein analysis. HOLMES features the ability to selectively enrich target biomolecules and simultaneously deplete non-targets directly in complex crude samples, thereby enormously enhancing the signal-to-noise ratio of detection.
1. Wei Ouyang, and Jongyoon Han, “Universal amplification-free molecular diagnostics by billion-fold hierarchical nanofluidic concentration,” Proceedings of the National Academy of Sciences of the United States of America (PNAS), DOI:10.1073/pnas.1904513116
2. Wei Ouyang, Zirui Li, and Jongyoon Han, “Pressure-Modulated Selective Electrokinetic Trapping for Direct Enrichment, Purification, and Detection of Nucleic Acids in Human Serum,” Analytical Chemistry, 90, 11366-11375 (2018)
3. Wei Ouyang, Xinghui Ye, Zirui Li, and Jongyoon Han, “Deciphering Ion Concentration Polarization-Based Electrokinetic Molecular Concentration at the Micro-Nanofluidic Interface: Theoretical Limits and Scaling Laws,” Nanoscale, 10, 15187 – 15194 (2018)
4. Wei Ouyang, Sung Hee Ko, Di Wu, Annie Wang, Paul Parone, William Hancock, and Jongyoon Han, “Rapid Assessment of Therapeutic Proteins Using Molecular Charge Modulation Enhanced Electrokinetic Concentration Assays,” Analytical Chemistry, 88(19), 9669–9677 (2016)