Electrochemical detection of DNA is a highly important topic. Here we show that the electrochemical responses of one DNA base (guanine, adenine, cytosine or thymine), in terms of oxidation potential, current intensity, peak width and resolution can be highly influenced by the presence of other DNA bases at electrochemically reduced graphene oxide (ER-GO) as well as standard glassy carbon electrode. We have observed that the effects were more significant for adenine base on ER-GO and cytosine base on glassy carbon (GC) electrode. Differences in responses were generally low in a mixture of four different DNA bases but interestingly, deviations become significantly larger when only one or two other bases were present. Our findings are of paramount importance for future developments in DNA detection and analysis since individual DNA bases are not present in isolation in nature or in typical biosensing systems.