Development of electrochemical sensor based on aptamer specific to lung cancer tumor marker

Electrochemical aptasensor is a sensor based on an indicator electrode covered with a layer of an aptamer that is able to bind target molecules with high specificity. In this work, DNA-aptamer LC-2108 specific to lung cancer tumor marker was immobilized onto the surface of golden screen-printed and disc electrodes. The electrodes were studied by conventional electrochemical methods–cyclic voltammetry and electrochemical impedance spectroscopy. The current increase and electron transfer resistance decrease were registered. It seems as if the aptamer presence facilitated the electron transfer through the electrode-solution boundary. As the possible reasons of such an unusual electrochemical behavior we proposed the unordinary or irregular structure of the aptamer layer on the Au surface or the specific electrochemical properties of the aptamer itself