Introduction: Vascular endothelial growth factor (VEGF) is acknowledged as a crucial biomarker for tumor angiogenesis, playing a significant role in the progression, development, and metastasis of tumors. Therefore, developing an ultra-sensitive detection method for VEGF is vital for early cancer prevention and surveillance of disease status.
Methods: In this research, we constructed a sandwich-style quenching electrochemiluminescence (ECL) immunosensor by employing the mechanism of electrochemiluminescence resonance energy transfer (ECL-RET), aiming for highly sensitive identification of VEGF165.
Results: The PTC@UIO-66-NH2 complex was prepared by integrating the organic luminescent probe, derived from the ammonolysis of Perylene-3,4,9,10-tetracarboxylic dianhydride (PTC), into the UIO-66-NH2 metal–organic framework. This complex was subsequently modified on the surface of a polished carbon electrode to serve as an ECL substrate. The VEGF antibody was then conjugated to this substrate via an amide reaction. Meanwhile, bovine serum albumin-functionalized MnO2 nanosheets (BSA-MnO2), which were linked to VEGF165 aptamers, functioned as the ECL acceptor. Upon selective recognition and binding to VEGF165, ECL-RET occurred between the PTC@UIO-66-NH2 (ECL donor) and BSA-MnO2 (ECL acceptor), leading to a significant reduction in the ECL signal, which could be readily captured by the instrument. Additionally, the intensity of the ECL response diminished as the concentration of VEGF165 increased. Under optimal experimental conditions, the ECL immunosensor exhibited a linear detection range spanning from 5 pg/mL to 50 ng/mL, with a minimum detectable limit of 3.5 pg/mL, which underscores its exceptional sensitivity. Furthermore, the ECL-RET immunoassay was subjected to rigorous validation procedures to confirm its specificity and stability.
Conclusions: In a nutshell, our ECL immunosensor presents a novel method for the early identification of VEGF in human serum, offering a fresh approach for timely detection. Furthermore, this technology depicts its potential to function as a flexible and promising platform, capable of detecting other circulating tumor biomarkers.
