Constructing a CA15-3 Ultrasensitive Fluorescent Probe Based on Dual-Ligand Peptides/UiO-66-NH2@AYG Composite Material.

Carbohydrate antigen 15-3 (CA15-3) is an important biomarker for early breast cancer diagnosis and therapeutic monitoring. This work presents an ultrasensitive fluorescent probe based on a dual-ligand peptides/UiO-66-NH2@AYG composite for CA15-3 detection. Dual-ligand peptides (GTTFSNYW and MHYLEYPF) target distinct CA15-3 epitopes, enhancing the binding affinity and specificity. The peptides are immobilized on UiO-66-NH2, whose high surface area supports efficient loading of the fluorescent reporter Acridine Yellow G (AYG). This probe demonstrates exceptional performance with a linear detection range of 0.05-1.5 pg/mL (R2 = 0.9981) and an ultralow detection limit of 0.004147 pg/mL. Practical validation in spiked mouse serum shows recovery rates of 91.57-103.7%, while clinical testing with serum samples from 10 cancer patients reveals a strong correlation with ELISA results (r = 0.9944, P < 0.001). This robust platform offers significant potential for cost-effective, early cancer screening in primary healthcare settings.