MXene-mediated fluorescent recombinase polymerase amplification for rapid and sensitive DNA methylation biosensing

DNA methylation serves as a promising biomarker for early cancer detection, with its assessment providing crucial insights for prognosis and diagnosis. Herein, we present a novel MXene-mediated fluorescent recombinase polymerase amplification (RPA) strategy that achieves rapid and sensitive non-small cell lung cancer (NSCLC)-associated methylated DNA detection. Remarkably, MXene can effectively quench the fluorescence of fluorescein amidate (FAM) labeled primer, with fluorescence recovery occurring as primers extend to double-stranded DNA and are released during the RPA process. This method exhibits exceptional sensitivity and selectivity, enabling the detection of methylated DNA at concentrations as low as 10 fM, with assay completion achieved in less than 1 h. Its ability to precisely evaluate gene-specific methylation showcases its potential to advance methylation as a disease biomarker, particularly in NSCLC.