Robust Electrochemical Aptasensing of VEGF Based on Poly-adenine Mediated DNA Self-Assembly and Triple Labeling of Silver Nanoparticles

Vascular endothelial growth factor (VEGF) is a cell-secreted signaling protein that is regarded as the biomarker and therapy target for certain diseases. In order to provide an accurate and robust sensing method, we herein construct a cost-effective electrochemical interface based on polyadenine-mediated DNA self-assembly and tetrahedral DNA (TDNA). The three-dimensional DNA nanostructure possesses multiple sites to immobilize silver nanoparticles (AgNPs) for strong electrochemical response, which also contains aptamer sequence against target VEGF. Thus, the density of AgNPs can be modulated by VEGF and the recorded stripping voltammetric signal can sensitively reflect the level of target protein. The electrode modification technique and recognition element improved the practical utility of this method. It is also challenged with human serum samples, and the results are consistent with the standard method. This sensor provides a feasible way to identify VEGF for potential clinical applications.