DNA Sensor Integrated CRISPR-Cas9 and a Four-Electrode Probe

This paper presents an electrochemical DNA sensor integrating CRISPR -Cas9 target recognition, gold nanoparticle signal amplification, and a glassy carbon microelectrode array in a four-electrode anodic stripping voltammetry system. The use of microfluidics and a dedicated oxidation electrode enhances gold nanoparticle signal capture and mass transfer efficiency. Applied to lateral flow assay samples, the sensor achieved a detection limit of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$5\times 10^{7} \ \text{copies}/\mu \mathrm{L}$</tex>, an improvement of two orders of magnitude compared to visual LFA intepretation, enabling more accurate detection of SARS CoV2 nucleic acid amplified by loop-mediated isothermal amplification. This platform significantly advances nucleic acid diagnostics by offering high sensitivity, quantification capability, and compatibility for point-of-collection testing.