Abstract: We devised and fabricated a chemosensor for determination of genetically relevant 5' GCGGCGGC 3' (G-guanine, C-cytosine) oligonucleotide. For that, we simultaneously electrosynthesized and electrode immobilized a sequence-defined octakis(2,2'-bithien-5-yl) DNA hybridizing probe using both a 'macromolecular imprinting in polymer strategy' and a sequence-programmable peptide nucleic acid (PNA) template. With EIS and SPR transductions under stagnant-solution and FIA, respectively, conditions, we determined the above oligonucleotide with 200 pM EIS limit of detection. With its EIS determined apparent impact factor of ~4.0, the chemosensor was discriminative to both mismatched oligonucleotides and Dulbecco Modified Eagle Medium sample interferences