A new triferrocenyl-tris(hydroxymethyl)aminomethane derivative as a highly sensitive electrochemical marker of biomolecules: application to the labelling of PNA monomers and their electrochemical characterization

We have designed and synthesised a new organometallic molecule containing three ferrocene groups for use as a highly sensitive electrochemical marker in biological assays. This trisferrocene derivative was conjugated to different PNA monomers, and the electrochemical activities of the conjugates were extensively investigated in organic solvents, in view of their potential diagnostic applications. The results showed that the introduction of a trisferrocene unit on the PNA monomer triples the current signal in comparison with the monoferrocene-labelled one. Despite their greater molecular molecular complexity, trisferrocene-conjugated PNA monomers are even more electrochemically active than the reference ferrocene. By using differential pulse voltammetry (DPV), the detection limit can reach 10-8 M in acetonitrile solution. These results are a good premise for the use of the trisferrocene unit as an effective electrochemical probe for biomolecules.