Abstract
PURPOSE: Early diagnosis of liver cancer requires highly sensitive detection of biomarkers. This study aims to develop a novel method for detecting circulating tumor DNA (ctDNA) in the serum of liver cancer patients, leveraging a catalytic hairpin self-assembly (CHA) signal amplification strategy combined with surface-enhanced Raman scattering (SERS) technology and nano-enzyme catalysis. METHODS: We synthesized Au@Pt@HP1-HP2@Fe(3)O(4) nano-enzyme complexes, utilizing the SERS-enhancing properties of Pt-coated Au nanoparticles (Au@Pt) and the separation-enrichment capability of Fe(3)O(4) magnetic beads. The complexes catalyzed the oxidation of colorless TMB by H(2)O(2) to produce blue ox-TMB, enabling quantitative detection of PIK3CA E542K mutant ctDNA. The assay's performance was validated using gold standard qRT-PCR. RESULTS: Under optimized conditions, the method achieved a detection limit for PIK3CA E542K as low as 4.12 aM. The assay demonstrated high sensitivity, specificity, and efficient magnetic separation, making it a robust tool for ctDNA detection. CONCLUSION: This study presents a highly sensitive and specific detection platform for liver cancer early diagnosis, characterized by magnetic separation and nano-enzyme catalysis. The method holds significant clinical potential for the accurate and early detection of liver cancer biomarkers.