dCas9-mediated Nano-electrohydrodynamic Direct Detection of Target Gene for Liquid Biopsy.

The-state-of-the-art bio- and nanotechnology have opened up an avenue to non-invasive liquid biopsy for identifying diseases from biomolecules in bloodstream, especially DNA. In this work, we combined sequence-specific-labeling scheme using mutated Clustered Regularly Interspaced Short Palindromic Repeats associated protein 9 without endonuclease activity (CRISPR/dCas9) and ion concentration polarization (ICP) phenomenon as a mechanism to selectively preconcentrate targeted DNA molecules for rapid and direct detection. Theoretical analysis on ICP phenomenon figured out a critical mobility, elucidating two distinguishable concentrating behaviors near a nanojunction; a stacking and a propagating behavior. Through the modulation of the critical mobility to shift those behaviors, the C-C chemokine receptor type 5 (CCR5) sequences were optically detected without PCR amplification. Conclusively, the proposed dCas9-mediated genetic detection methodology based on ICP would provide rapid and accurate micro/nanofluidic platform of liquid biopsies for disease diagnostics.