Studies on an electrochemical DNA biosensor based on gold nanoparticle-labeled DNA probe

An electrochemical detection method for the analyzing sequence-specific DNA using gold nanoparticle labeled oligonucleotide DNA probes has been developed. Target DNA were covalently immobilized on a glass carbon electrode and. incubated with gold nanoparticle-labeled DNA probes, containing a complementary sequence. Binding events were monitored by electrochemical signal of gold nanoparticle hybridized to the electrode surface. The signal difference permits to distinguish the Match of,two perfectly complementary DNA strands from the near-perfect match where just one base pair was wrong. The sensitivity of this electrochemical DNA blosensor has been detected and a detection limit of 1.0 nmol/L of oligonucleotides was achieved.