A sensor for detecting analytes is described. Analyte presence or concentration is determined through measurement of changes in induced electromotive force, current or other electrical property in a base member during analyte exposure to the sensor. According to one class of embodiments, the present device immobilizes natural or synthetic macromolecules sufficiently close to an electrically-conductive base member to insure that any alteration in the motion and/or electrostatic fields of the macromolecules during interaction with a predetermined analyte will induce an increased electromotive force in the base member.