2024 Development of an Aptamer-Based QCM-D Biosensor for the Detection of Thrombin Using Supported Lipid Bilayers as Surface Functionalization
Authors:
Anne Görner1, Leyla Franz1, Tuba Çanak-Ipek2, Meltem Avci-Adali2 and Anna-Kristina Marel1,*
Journal:
Journal: Biosensors 2024,14, 270. doi.org/10.3390/bios14060270
Institute:
1Department of Food Technology and Bioprocess Engineering, Max Rubner-Institut, Federal Research Instituteof Nutrition and Food, 76131 Karlsruhe, Germany; 2Department of Thoracic and Cardiovascular Surgery, University Hospital Tübingen,72076 Tübingen, Germany;
Abstract:
Biosensors play an important role in numerous research fields. Quartz crystal microbalanceswith dissipation monitoring (QCM-Ds) are sensitive devices, and binding events can be observedin real-time. In combination with aptamers, they have great potential for selective and label-freedetection of various targets. In this study, an alternative surface functionalization for a QCM-D-based aptasensor was developed, which mimics an artificial cell membrane and thus creates aphysiologically close environment for the binding of the target to the sensor. Vesicle spreadingwas used to form a supported lipid bilayer (SLB) of 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine(POPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphethanolamine-N-(cap biotinyl) (biotin-PE). The SLBwas then coated with streptavidin followed by applying a biotinylated aptamer against thrombin.SLB formation was investigated in terms of temperature and composition. Temperatures of 25◦Cand below led to incomplete SLB formation, whereas a full bilayer was built at higher temperatures.We observed only a small influence of the content of biotinylated lipids in the mixture on the furtherbinding of streptavidin. The functionalization of the sensor surface with the thrombin aptamer andthe subsequent thrombin binding were investigated at different concentrations. The sensor could bereconstituted by incubation with a 5 M urea solution, which resulted in the release of the thrombinfrom the sensor surface. Thereafter, it was possible to rebind thrombin. Thrombin in spiked samplesof human serum was successfully detected. The developed system can be easily applied to othertarget analytes using the desired aptamers.