Electrochemiluminescence aptasensor for vascular endothelial growth factor 165 detection based on Ru(bpy)₃²⁺/Au...

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 RecJ_f 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.