Enzymatic redox 3′-end-labeling of DNA oligonucleotide monolayers on gold surfaces using terminal deoxynucleotidyl transferase (TdT)-mediated single base extension

The creation of electrochemical DNA detection methods is of scientific and technological significant importance. In this study, we report an unprecedented surface enzymatic methodology for easy, rapid, and efficient redox labeling of ssDNA. This labeling strategy, based on the use of terminal transferase enzyme (TdT), localizes a single ferrocene unit at the 3'-end of the 5'-grafted ssDNA probe, and has the unique advantage of being template-independent. The application of such universal technology is expected to be easily adapted to various specific researches.