Sensitive detection of tumor cells by a new cytosensor with 3D-MWCNTs array based on vicinal-dithiol-containing proteins (VDPs)

Vicinal-dithiol-containing Proteins (VDPs) are overexpressed in cancer cells and become a potential biomarker for aggressive tumors, the synthesized 2-p-aminophenyl-1, 3, 2-dithiarsenolane (VTA2) is proved to be a highly selective ligand for vicinal dithiols of VDPs in cells. In this report, we developed a new cytosensor based on three-dimensional (3D)-like VTA2-conjugated multiwalled carbon nanotubes (VTA2@MWCNTs) array modified indium tin oxide (ITO) electrode for sensitive and selective detection of VDPs-overexpression tumor cells. The layer-by-layer assembling and cellular detection performances of the 3D-VTA2@MWCNTs-based cytosensor were investigated by atomic force microscopy (AFM) and electrochemical methods including cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). Attributed to signal amplification and targeting recognition of the 3D-structured MWCNTs@VTA2, the fabricated cytosensor showed high specificity and sensitivity to the detection of VDPs-overexpression HL-60 cells ranging from 2.7×102 to 2.7×107cellsmL−1 with a low detection limit of ca. 90cellsmL−1. Furthermore, the captured cancer cells on the cytosensor also could be directly visualized by optical microscopy technology. This proposed 3D-MWCNTs array-based cytosensing strategy provides a simple, sensitive approach for non-invasive cell detection, presenting potential applications in cancer diagnosis. •A sensitive and selective cytosensor based on three-dimensional (3D)-like MWCNTs array modified ITO electrode was developed.•Synthesized target ligand VTA2 molecule was introduced into the cytosensor for specific recognition of VDPs overexpressing tumor cells, which affords an alternative to antibody-based biosensor.•The proposed cytosensor may enable for a dual functional detection of cancer cells based on both electrochemical and optical image technology.