In this work, high performance organic thin-film transistors (OTFTs) are demonstrated based on an eco- friendly gate dielectric consisting of a bilayer combination of two biodegradable nature-based materials chitosan and gelatin. TIPS-pentacene and Polystyrene (PS) blend was used as an active layer to obtain highly stable OTFT devices. Fabricated p-type devices exhibited excellent electrical characteristics with maximum field-effect mobility of 1.6 cm2 V-1s-1 with average of 1.1 cm2 V- ¹ s- ¹ and a relatively low threshold voltage of −0.5V for a low operating voltage of −5 V. Various electrical tests, including repeatability and bias-stress stability were performed to evaluate the device's operational and electrical stability. Further, circuit applicability was also evaluated by the external resistive load connected inverter characteristics.