Electrochemical determination of vascular endothelial growth factor using functional metal-polymer nanocomposites

Abstract

Vascular endothelial growth factor (VEGF) is a homo-dimeric glycoprotein that plays a prominent part in the pathophysiology of angiogenesis and vasculargenesis, such as tumorigenesis, vascular permeability and metastasis. Quantification of VEGF in the body is significant for clinical diagnosis and treatment. An electrochemical sensor for the sensitive determination of VEGF was developed. Functional metal-polymer nanocomposites, gold nanoparticles@poly(o-phenylenediamine) (AuNPs@PoPD), and AuNPs@PoPD-labeled VEGF antibodies (Ab-AuNPs@PoPD) were synthesized. The glassy carbon electrode modified with graphene nanoribbons (GNRs), AuNPs and VEGF, GCE/GNRs-AuNPs/VEGF, was fabricated and it was employed to capture Ab-AuNPs@PoPD. Free VEGF proteins had an inhibitory action on the assembly of GCE/GNRs-AuNPs/VEGF/Ab-AuNPs@PoPD, leading to the decrease of the electrochemical probe, PoPD, on the modified electrode and the decline of current signal in the voltammetic measurement. Under the optimal experimental conditions, the peak current difference was proportional to the VEGF concentration in the range of 0.500–500 ng mL−1 and the limit of detection was 300 pg mL−1. The proposed sensor exhibited a good selectivity, reproducibility and stability. High-salt microenvironment induced the dysfunction of human umbilical vein endothelial cells (HUVECs). Electrochemical measurements reveal that increasing NaCl concentration in the growth medium promoted the release of VEGF from dysfunctional HUVECs.