Abstract

Enzymatic Biosensor to Support the Diagnosis of Adrenal Gland Tumors

Michael Schöning, Director of Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences

Primary aldosteronism (PA) is a disorder in which aldosterone production is inappropriately high and causes hypertension. The clinical guidelines advocate using adrenal vein sampling (AVS) to diagnose PA. However, since AVS is a demanding procedure in which correct cannulation of adrenal veins is challenging, it is used only in a few centers worldwide. To facilitate this medical examination, the detection of adrenaline during AVS could be used as an indicator for the correct position of the catheter, since the adrenaline concentration in adrenal blood (100 nM) is about 100 times higher in comparison to peripheral blood (1 nM).

Two different biosensor approaches for the detection of adrenaline will be presented, which are based on the substrate recycling principle. The first variant is based on an amperometric bi-enzyme biosensor with a genetically modified laccase and a glucose dehydrogenase (GDH). The second example represents a chip-based biosensor with the enzyme PQQ-GDH. Both sensor types have been optimized under laboratory conditions and successfully applied for first measurements in real blood samples, to define an appropriate catheter position.