A conductive compound of formula (I) below, an electrode coated with the conductive compound, a sensor including the electrode, and a target molecule detection method using the sensor are provided: ##STR00001## wherein Y is a carbonyl or --NH--; R is one of H, OH, a leaving group, and a probe group; l is an integer from 3 to 6; m is an integer from 1 to 4; and n is an integer from 0 to 3.