Au@Pt@HP1-HP2@Fe3O4 Nanoenzymatic Complexes Based on CHA Signal Amplification Strategy for Ultrasensitive SERS...

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.

We synthesized Au@Pt@HP1-HP2@Fe₃O₄ nano-enzyme complexes, utilizing the SERS-enhancing properties of Pt-coated Au nanoparticles (Au@Pt) and the separation-enrichment capability of Fe₃O₄ magnetic beads. The complexes catalyzed the oxidation of colorless TMB by H₂O₂ to produce blue ox-TMB, enabling quantitative detection of PIK3CA E542K mutant ctDNA. The assay's performance was validated using gold standard qRT-PCR.

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.

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.