Quantum mechanical investigations were performed to find a suitable sensitizer to peptide nucleic acid (PNA) monomer with Adenine and Guanine basis. It was shown that interaction of the orbitals of the isolated PNA sequence with Adenine-Guanine and isolated sensitizer should be present. It was found that the 3-(N, N-dimethyl)-6-(N’-acetilaminel-N’-methyl) acridindiamine molecule could be used as a sensitizer.