Abstract: This invention relates generally to electro-anatomical mapping method and an apparatus using a catheter and more particularly to a mapping catheter having an embedded MOSFET sensor array for detecting local electrophysiological parameters such as biopotential signals within an excitable cellular matrix geometry, for determining physiological as well as electrical characteristics of conduction path and its underlying substrate within the endocardial and epicardial spaces, the arterial structure and in ganglionic plexus. The apparatus with its MOSFET sensor is geometrically configured as a decapolar linear array and optionally with an 8×8 sensor matrix placed on a balloon-like structure.