Vascular endothelial growth factor (VEGF) plays a critical role in angiogenesis and is considered a crucial prognostic biomarker in various types of cancer. This study developed a novel platform for detecting VEGF using phage binding specificity and the sensitivity of quantum dot (QD) nanocrystals. Specifically, the phage displaying camelid heavy-chain variable domain (VEvhh3) particles as anti-VEGF agents and signal transmission sensitivity amplifier QDs were utilized. The thioglycolic acid (TGA)-CdTe QDs were conjugated with the phage cage using covalent linkages achieved through EDC and Sulfo-NHS as a cross-linker. To detect VEGF, a sensitive immune-fluorescence method based on phage display-mediated immuno-fluorescence (PD-IFL) QDs was developed, using avastin as the capture antibody. This method demonstrated a limit of detection (LOD) of 0.24 pg mL−1 and a linear range of 0.001–1000 ng mL−1. The recovery rate varied from 96.96 % to 102.46 %, with a relative standard deviation of 0.558–2.258 % in serum. These findings indicate the suitability and sensitivity of the PD-IFL assay for clinical analysis. Overall, our method shows superior sensitivity, specificity, and stability when compared to traditional methods such as ELISA, making it a promising tool for the clinical analysis of VEGF levels in patients with early-stage cancer.
2025.
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