Sensitive electrochemical detection of von Willebrand factor using an immunosensor comprising 7,7,8,8-tetracyanoquinodimethane and nickel-based metal–organic framework

Abstract

In this work, we developed an immunosensor for determining von Willebrand factor (VWF) by combining a nickel-based metal–organic framework (NiBTC) with 7,7,8,8-tetracyanoquinodimethane (TCNQ), assembling them on a screen-printed electrode (SPE), and immobilizing VWF antibodies on the surface to obtain Ab/TCNQ-NiBTC/SPE. The capture of VWF antigens caused steric hindrance, which mitigated the electrochemical response. The immunoreaction caused a change in the peak current of Ab/TCNQ-NiBTC/SPE, which was proportional to the logarithm of VWF concentration in the range of 1–200 ng/mL, with limits of detection and quantification of 0.887 ng/mL and 2.958 ng/mL, respectively. The proposed Ab/TCNQ-NiBTC/SPE was used to investigate the release of VWF from H2O2-induced oxidative-injured human umbilical vein endothelial cells. The extent of cell injury and the amount of VWF released increased with an increase in the exposure time to H2O2; however, as the cells died due to excessive injury, the amount of VWF released decreased. The proposed TCNQ-NiBTC-based immunosensor can facilitate the convenient and accurate detection of VWF.