DNA Aptamers that Bind to PQQGDH as an Electrochemical Labeling Tool

We screened DNA aptamers that bind to pyrroquinoline quinone glucose dehydrogenase (PQQGDH) for the development of an electrochemical labeling tool. PQQGDH is an excellent enzyme for the signal amplification of biosensors. We focused on DNA aptamers as labeling agents and tried to select those DNA aptamers that bind to PQQGDH without affecting its enzymatic activity. After 7 rounds of screening, one aptamer was obtained: ‘PGa4’. It bound to PQQGDH with specificity and showed no effect on the glucose dehydrogenase (GDH) activity. Moreover, beads labeled with PQQGDH via PGa4 generated an electrical current upon glucose addition. Therefore, we believe that the PGa4 aptamer against PQQGDH may become a powerful labeling tool for electrochemical biosensors.