With an excellent stability profile, ferrocene has always attracted considerable interest for DNA labeling to generate probes for electrochemical detection. Dimethylaminophenothiazin-5-ium chloride, Methylene Blue (MB), has many uses in chemistry and biology. For decades, this compound has been used for applications including redox indicator, photosensitizer, dye for cellular staining procedures, antiseptic and in medicine against Alzheimer's disease. For the detection of biological analytes, MB has also been used as a redox reporter bound to DNA probes.