ElectrochemicalAptasensing of Vascular EndothelialGrowth Factor by Construction of DNA Triangular Pyramid Frustum ReactionInterface

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.