Biochemical microsensors on the basis of metabolically sensitive hydrogels

With the rapid development of micro systems technology and microelectronics, smart electronic systems are emerging for the continuous surveillance of relevant parameters in the body and even for closed-loop systems with a sensor feedback to drug release systems. With respect to diabetes management, there is a critical societal need for a sensor that can be used to continuously measure a patient's blood glucose concentration twenty four hours a day on a long-term basis. In this work, thin films of "stimuli-responsive" or "smart" hydrogels were combined with microfabricated piezoresistive pressure transducers to obtain "chemomechanical sensors" that can serve as selective and versatile wireless biomedical sensors. The sensitivity of hydrogels with regard to the concentration of glucose in solutions with physiological pH, ionic strength and temperature was investigated in vitro. The response of the glucose-sensitive hydrogel was studied at different regimes of the glucose concentration change and at different temperatures. Sensor response time and accuracy with which a sensor can track gradual changes in glucose was estimated.