Graduate Research and Discovery Symposium (GRADS)


Implantable Wireless Dual-analyte Biosensor for Trauma Patient Monitoring and Management


Anthony Guiseppi-Elie

Document Type




Publication Date

Spring 2013


Amperometric enzyme-based biosensors are being designed as rapidly deployable, minimally invasive diagnostic, microchip technology for the continual measurement of metabolic markers of trauma, such as glucose and lactate. Dual responsive, multi-disc electrode-array working electrodes consisting of 37 platinum microdiscs (d=50 µm, d/r=4) were coated with biosmart hydrogel. Electropolymerization of polypyrrole was used to generate a conducting electroactive polymer (0.1-250 mC/cm2) that formed an interpenetrating network throughout the biosmart hydrogel while simultaneously entrapping enzymes. Biosensors had a response time of 2-8s. Linear ranges for glucose response of the implantable MDEA system were 1-5 mM and 8-33 mM. A sensitivity of 0.42 µA/cm^2/mM, a KMapp of 0.566 mM, and an Imax of 5.40 µA/cm^2 were observed. The detection limit was 0.02 mM. A precise dose response within the physiologically relevant range of glucose was observed. Polypyrrole decreased sensitivity to negatively charged interferrents with a rejection ratio of 12:1. Interferrent response was limited to 3-5% of the total response to glucose at low concentration. The system was stable while stored in PBS and demonstrated increasing sensitivity over 21 days. Dual analyte sensing using a wireless potentiostat was successful with minimal crosstalk between electrochemical cells. Error between cells did not exceed 5%.

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