Manganese dioxide screen printed graphite electrodes for electro-analytical sensing purposes have been fabricated. The prepared sensors exhibit attractive performances as electro-catalysts for the sensing of nitrite ions and ascorbic acid with detection limits comparable or lower than those obtainable with other electrochemical sensors. The manganese dioxide platforms are also explored towards the electrochemical reduction of oxygen which has importance in electrochemical energy storage. While the platforms are found to operate by a four-electron reduction producing water (rather than hydrogen peroxide which is undesirable), a large overpotential, compared to other possible electrode compositions reported in the literature, is required. Nevertheless, the promising results towards the electro-analytical sensing of nitrite ions and ascorbic acid and also given the disposable nature and scale of economies make these electrodes useful as sensor platforms.