A high sensitive electrochemical aptasensor for the determination of VEGF165 in serum of lung cancer patient

Herein, a label free electrochemical aptasensor based on ordered mesoporous carbon-gold nano-composite modified screen printed electrode has been fabricated for the detection of vascular endothelial growth factor (VEGF(165)) as a tumor marker. The electrochemical behavior of prepared biosensor was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The principle of operation of the proposed aptasensor is based on the changes in the interfacial properties of the electrode due to interaction of the immobilized antiVEGF(165) aptamer at the electrode surface with VEGF(165) tumor marker in the sample solution, which results in a change in the interfacial charge transfer resistance as detected by electrochemical impedance spectroscopy. The calibration curve for VEGF(165) determination was linear over 10.0-300.0 pg mL(-1) with a limit of detection (3 sigma/S) of 1.0 pg mL(-l). The prepared aptasensor exhibited high sensitivity and good selectivity and reproducibility. The aptasensor was successfully applied to the determination of VEGF(165) in serum sample of a lung cancer patient. (C) 2015 Elsevier B.V. All rights reserved.