A label and indicator free electrochemical DNA hybridization detection method based on a manganese(IV) oxide nanomaterial modified glassy carbon paste composite electrode (MnO2-Nm/GCPE) was developed. 22-mer oligonucleotides representing E. coli bacteria were used as a model case. To the best of our knowledge, this study is the first study in which MnO2-Nms were incorporated into GCPE and used as a genosensor transducer. The extent of hybridization was determined by using differential pulse voltammetric signals of guanine oxidation. By incorporating MnO2-Nm into the electrode structure, a more sensitive guanine signal was obtained when compared to plain GCPE. After optimization of the experimental parameters, the detection limit was calculated to be 1.31 x 10(-9) M.