Recent significant developments in sensor science and technology, such as the design of ultramicroelectrodes and arrays, are providing considerable stimulation in research. This book offers insight into the various extended applications and developments of N4 macrocycle complexes in the field of biomimetic electrocatalysis. Chapters are devoted to the chemistry, electronic and electrochemical properties of porphyrin- based polymetallated supramolecular redox catalysts and their applications in analytical and photoelectrochemical molecular devices; the use of porphyrins, phthalocyanines and related complexes as electrocatalysts for the detection of a wide variety of environmentally polluting and biologically relevant molecules; and the use electropolymerized metalloporphyrin and metallophthalocyanine films as powerful materials for analytical tools, especially for sensing biologically relevant species.