A simple and rapid electrochemical strategy for non-invasive, sensitive and specific detection of cancerous cell

Developing non-invasive, sensitive and specific sensing strategies for cancerous cell detection with simple and low cost instrumentations provide great advantages in cancer research and early diagnosis of diseases. In the present work, gold nanoparticles (Au NPs) functionalized with recognition components (folic acid) and signal indicator (ferrocene) was designed to fabricate electrochemical cytosensor. The Au NPs can not only accelerate electron transfer between signal indicator and the underlying electrode but also accumulate more ferrocene on the cytosensor surface to magnify signal for improving detection sensitivity. The surface-tethered folic acid plays a key role in specific binding folate receptor-riched HeLa cells on the cytosensor surface, resulting in corresponding current signal change measured by differential pulse voltammetry method. A wide detection range from 10 to 106 cells/mL with a detection limit as low as 10 cells/mL for cancerous cells was reached in the presence of a large amount of normal ones with fast differential pulse voltammetry measurement. Detection of the captured cells can be finished within 1 min. The developed strategy provides a new way for operationally simple, rapid, sensitive and specific detection of cancerous cells.