A portable microfluidic platform for ultra-sensitive detection of ovarian cancer biomarkers via cascade signal amplification

Early detection of ovarian cancer is crucial for improving treatment outcomes and increasing survival rates, as this malignancy is often diagnosed at an advanced stage due to the lack of specific early symptoms. In this study, we present a novel diagnostic platform integrating platinum nanozyme-induced cascade signal amplification with a gas-driven visual amplification chip (VAC) for the sensitive and specific detection of the ovarian cancer biomarkers CA125 and HE4. This system leverages a sandwich complex formed by capture antibodyfunctionalized magnetic silica nanoparticles and detection antibody-functionalized platinum nanoparticles in the presence of target antigens. The PtNPs' peroxidase-like activity catalyzes dopamine polymerization, leading to polydopamine deposition and subsequent capture of 4-mercaptophenylboronic acid-modified platinum nanoparticles, amplifying the detection signal. The VAC achieved exceptional sensitivity, with detection limits as low as 0.001 U mL- 1 for CA125 and 0.1 pg mL- 1 for HE4, surpassing traditional methods. Finally, the platform demonstrated a strong correlation with electrochemiluminescence assays, making it a promising tool for point-ofcare testing and early ovarian cancer detection in clinical settings.