A lift-off method for patterning enzyme-immobilized membranes in multi-biosensors

Abstract A new method for preparing enzyme-immobilized membranes of multi- biosensors has been developed and demonstrated by fabricating a multi- biosensor for glucose and urea, based on the pH-selective ion-sensitive field effect transitor. The enzyme solution, containing glutaraldehyde, is spin coated onto a water covered with a patterned photoresist. The resulting enzyme-immobilized membrane is lifted off by ultrasonic vibration in acetone, except for the membrane on the transitor gates. The deposited membrane is precisely patterned and difficult to peel off. The method is compatible with IC processes and applicable to multi-biosensor mass production