A quantum dots-based electrochemical assay towards the sensitive detection of tumor cells

A new electrochemical assay strategy was proposed based on the specific recognition of folate receptors on a cell surface to folic acids. Indium tin oxide glass (ITO) surfaces were silanized by (3-aminopropyl) trimethoxylsilane (APTMS) to associate to Au nanoparticles (AuNPs) which can effectively capture cells. Then, CdSe/ZnS quantum dots (QDs)-labeled folic acids (FAs) can couple with the folate receptors (FRs) on the KB cells, which can overexpress FRs. By square wave stripping voltammetry (SWSV), the developed electrochemical assay showed an excellent analytical performance for the sensitive detection of KB cells as low as 2000 cells mL(-1). The QDs-based electrochemical assay provides a rapid and reliable platform towards the tumor cell quantification and thus has the potential in the improvement of cancer diagnosis and treatment. (c) 2013 Elsevier B.V. All rights reserved.