Electrochemiluminescence aptasensor for vascular endothelial growth factor 165 detection based on Ru(bpy)32+/Au nanoparticles film modified electrode and double signal amplification

Abstract

Vascular endothelial growth factor (VEGF165) is a signal protein that plays a central role in the regulation of angiogenesis and can stimulate angiogenesis. The development of highly sensitive and selective detection method for VEGF165 is very important for disease diagnosis and follow-up treatment monitoring. In this study, an electrochemiluminescence (ECL) aptasensor for VEGF165 has been developed based on quench of H2O2 toward Ru(bpy)32+/TPrA ECL system and RecJf exonuclease induced target recovery and hybridization chain reaction (HCR) as amplification strategy. The presence of VEGF165 makes a large number of glucose oxidase (GOD) fixed on the electrode surface through the double signal amplification strategies. The present of GOD cause the production of a large amount of H2O2 near the electrode surface under excess amount of glucose, resulting in the inhibition of the ECL signal of Ru(bpy)32+/Au nanoparticles (Ru(bpy)32+/AuNPs) film fixed on the electrode surface. The ECL response of the designed biosensor has a good linear relationship with the logarithm of the concentration of VEGF165 in the range of 0.5 pg/mL to 500 ng/mL with a detection limit of 0.2 fg/mL. The VEGF165 in serum samples has been detected by the proposed aptasensor with satisfactory results.