Liquid Biopsy and Non-invasive Biomarkers

In the context of global aging and the prevalence of various diseases, traditional invasive diagnostic techniques have their limitations. Liquid biopsy, with its non-invasive and convenient features, has become a research hotspot. This article reviews its development process, from the qualitative detection of cfDNA discovered at the end of the 20th century, to the quantitative detection facilitated by NGS. And then to the clinical applications. The system comprehensively analyzes the mechanism and detection methods of key biomarkers such as cfDNA, exosomes, and CTCs. Elaborate on the innovative directions of biomarker enrichment (such as nanomaterial strategies) and multi-omics analysis algorithms (such as CNN models). At the same time, the challenges in terms of technology (stability, cost), clinical (validation data, scenario definition), and regulatory and ethical aspects of transformation were also pointed out. Introduce the research progress of ultra-high sensitivity and multi-modal integration technology. We explore cutting-edge directions such as single-cell detection and AI integration, aiming to provide theoretical references for the clinical application of liquid biopsy.