A self-assembled monolayer based electrochemical immunosensor for detection of leukemia K562A cells

A novel strategy to quantify the cell number of leukemia K562A cells using electrochemical immunosensor was developed by effective surface immunoreaction between P-glycoprotein (P-gp) on cell membrane and P-gp mouse monoclonal antibody bound on an epoxysilane monolayer modified glassy carbon electrode. The surface morphologies of the epoxysilane monolayer and the bound antibodies were studied with atomic force microscopy. The binding of target K562A cells onto the immobilized antibodies increased the electron-transfer impedance of electrochemical probe, which depended linearly on the cell concentration in the range of 5.0 x 10(4)-1.0 x 10(7) cells mL(-1). The detection limit of the immunosensor was 7.1 x 10(3) cells mL(-1). The proposed strategy showed acceptable reproducibility with an RSD of 3.4%, for the linear slope and good precision with the RSD of 3.7% and 3.0% examined at the cell concentrations of 2.0 x 10(6) and 1.0 x 10(7) Cells mL(-1). (c) 2007 Elsevier B.V. All rights reserved.