Switchable ‘on–off–on’ electrochemical technique for direct detection of survivin mRNA in living cells

Survivin is a new member of apoptosis inhibition protein in cells which can promote cell proliferation and inhibit apoptosis through karyokinesis. Survivin mRNA in cells has become an important biomarker for early and accurate cancer diagnostics. Here, a switchable electrochemical sensor for survivin mRNA in living cells has been designed, which is based on the changes of electron transfer efficiency between ferrocene at the end of DNA and the electrode surface after reaction with survivin mRNA. The method was then used to study populations of individual cells with different levels of mRNA. Based on the different current changes, it was possible to evaluate different cell populations and cell status on the basis of the amount of mRNA levels in cells. This strategy may provide a new direction in the fabrication of high-performance electrochemical biosensors for the detection of biomolecules in living cells.