Templated seed-mediated derived Au nanoarchitectures embedded with nanochitosan: Sensitive electrochemical aptasensor for vascular endothelial growth factor and living MCF-7 cell detection

Abstract We synthesized a novel Au nanoarchitecture (Au NA) embedded with nanochitosan (NC) (denoted as AuNA@NC) and employed as a new platform of the aptasensor for simultaneously and sensitively detecting the cancer marker, vascular endothelial growth factor (VEGF165), and living MCF-7 cells. Comparing with the hollow pristine Au NA, the NC containing in AuNA@NC covers the surface and fills in the interior of the whole framework, giving a relatively solid structure and therefore leading to enhanced conductivity and high electrochemical activity of AuNA@NC. The AuNA@NC composite was then employed as the sensitive layer for immobilizing the vascular endothelial growth factor (VEGF165)-anti aptamer strands to construct electrochemical aptasensor for detection of VEGF165 and living MCF-7 cells. Since the AuNA@NC composite combines the advantages of good biocompatibility of NC, and strong bioaffinity and hollow framework of Au NAs, the developed AuNAs@NC-based aptasensor exhibits high sensitivity for detecting VEGF165 with a low limit of detection (LOD) of 6.77 pg·mL−1 and MCF-7 cells, along with high selectivity, good stability and reproducibility, acceptable regenerability, and applicability in real serum samples. All of these suggest that the AuNAs@NC displays promising applications in disease diagnosis and subsequent therapy monitoring.