Optimized Packaging and Storage Strategies to Improve Immunosensors’ Shelf-Life

Objectives: immunosensors are a versatile technology enabling affinity-based detection of a large variety of molecular targets. Their common use in practice, however, is limited due to the instability of the antibodies and therefore shelf-life issues. Despite the negative impact of these challenges on the commercialization of such sensors, not many studies have provided solutions in this regard. This work illustrates how the experience from the food packaging industry could help reduce the negative effect of environmental factors such as O-2, humidity, and temperature on the performance of immunosensors and improve their long-term stability. To the best of our knowledge, this approach is completely novel. Methods: Different packaging approaches, namely vacuum packaging, and packaging under modified atmosphere along with multilayer packaging material with good to excellent gas and water barrier properties based on the food packaging studies were compared. The packed samples were exposed to different storage conditions (humidity and temperature) to determine the optimum storage condition. Results: The tray-top-film with Polyamide (PA)/ethylene vinyl alcohol copolymers (EVOH)/PA/polyethylene (PE)/polypropylene (PP) foil, flushed with 100% N-2, packed within 2-h after the fabrication of the immunosensor was concluded as the optimum packaging. With regard to relative humidity, values below 50% should be considered during the packaging process and storage to avoid possible dehydration of the immunosensor and so its over time performance loss. When packed under these conditions, the shelf-life of the immunosensor is increased to more than six months even if stored in room temperature.