Reagentless Aptamer Based Impedance Biosensor for Monitoring Adenosine

A simple and highly sensitive electrochemical impedance spectroscopy (EIS) biosensor based on nano-MnO2 as a platform for the immobilization of the aptamer was developed for the determination of adenosine. In the measurement of adenosine, the change in interfacial electron transfer resistance (R-et) of the biosensor using a redox couple of [Fe(CN)(6)](3-/4-) as the probe was monitored. The change of the electron transfer resistance (Delta R-et) of the biosensor was linear with the concentration of adenosine in the range from 1.0 nM to 100 nM. Pie fabricated sensor was shown to exhibit high sensitivity, desirable selectivity and good stability.