To provide a method of probing for a nucleic acid and comprising: bringing a nucleic acid solution into contact with an oligonucleotide probe labeled with an electrochemically active marker; providing conditions at which the probe is able to at least partially hybridize with any complementary target sequence which may be present in the nucleic acid solution; selectively degrading either hybridized, partially hybridized or unhybridized nucleic acid probe; and electrochemically determining information relating to the electrochemically active marker, and further to provide a new molecule with use in the method.

A compound with a specific structure comprises an oligonucleotide having a labeled atomic group and a sequence hybridizable to a target.