In this work, to show the proof of concept, we have considered two anti-hypertensive tripeptides Isoleucine-Proline-Proline (IPP) and Leucine-Lysine-Proline (LKP) derived from milk β-casein . The FET sensor is immersed in an electrolyte with SiO2 as the gate oxide. (3-Aminopropyl)triethoxysilane (APTES) is deposited on SiO2 as a linker to facilitate the immobilization of the oligopeptides , , . The presence of linker , , and nonspecific binding - , , can be extracted by calibrating the sensor. The variation in device behavior is captured by analyzing surface potential (Ψo), 2 nd gradient of Ψo ( ⁄