ABSTRACT
For the short-lived species nitric oxide and superoxide various sensor approaches for their detection have been reviewed. Sensors provide access to a time and spatially resolved analysis basing a deeper insight into the physiological role and interaction of both radicals. Superoxide sensing is mainly based on electrodes modified with cytochrome c or superoxide dismutase as recognition elements. For NO quantification optrodes as well as electrodes can be used, with a higher sensitivity for the latter. Electrodes were modified with transition metal complexes, simple gas permeable membranes or heme proteins.