This communication describes the synthesis of an electrochemically active oligonucleotide probe and its application in sensing complementary oligonucleotides sequences using a T7 exonuclease enzyme. Target oligonucleotides are detected by hybridisation with a ferrocene labelled probe oligonucleotide followed by addition of T7 exonuclease. The T7 enzyme is a double strand specific exonuclease that removes the terminal 5' nucleotide of the probe sequence. The 5' nucleotide is attached to a ferrocene label, which is subsequently detected at an electrode using differential pulse voltammetry. Time and temperature resolved measurements were performed and an associated study using dual labelled fluorophore-quencher labelled probes was performed to confirm the validity of the electrochemical assay.
- T7 exonuclease
Hillier, S. C., Flower, S. E., Frost, C. G., Jenkins, A. T. A., Keay, R., Braven, H., & Clarkson, J. (2004). An electrochemical gene detection assay utilising T7 exonuclease activity on complementary probe-target oligonucleotide sequences. Electrochemistry Communications, 6(12), 1227-1232. https://doi.org/10.1016/j.elecom.2004.09.019