Electrochemical Aptasensing of Vascular Endothelial Growth Factor by Construction of DNA Triangular Pyramid Frustum Reaction Interface

Vascular endothelial growth factor (VEGF) is an important regulatory factor of angiogenesis, which is considered a meaningful biomarker for certain diseases. In this study, we demonstrate the development of a highly sensitive electrochemical method for the detection of VEGF based on aptamer-mediated recognition and gold nanoparticle-assisted signal enhancement. The aptamer sequence is localized at the top of the DNA triangular pyramid frustum nanostructure, which was previously immobilized on the surface of a gold electrode. The three-dimensional DNA nanostructure provides a suitable reaction interface. Reliable impedimetric responses are measured to reflect the initial level of VEGF as the trigger of DNA nanostructural transition. Under optimized experimental conditions, a limit of detection as low as 5.0 pg/mL is achieved. In addition, this method performs satisfactorily in biological samples and is well-consistent with the commercial enzyme linked immunosorbent assay (ELISA). The selectivity is also excellent, which could distinguish the target protein from potential interfering species.