General Overview - Engineering Routine from Laboratory Biosensor to On-site Test Kit
      In order to make engineered biosensor cells suitable for on-site testing, we have adopted a PVA-PEG hydrogel cell immobilization approach. The primary reason is to avoid liquid bacteria culture handling, ensuring both safety and user-friendliness. Another reason is to speed up the detection process. We found in the literature that hydrogel could allow hydrophobic substances, in our case, cereulide, to diffuse in the medium and better interact with biosensor cells, enhancing detection efficiency.
      To make our on-site test kits a qualified product for the market, a long enough shelf life is needed. Therefore we put spores instead of cells into the hydrogel. Sporulation of B. sub. was induced by nutrient exhaustion during construction. When the cells become endospores, they can survive in a non-favourable environment. After activation by nutrients, the performance of the sensor remains unaffected.
Hardware Cycle 0
Is PVA hydrogel good for biosensors that use fluorescence as reporters?
Hardware Cycle 1
Biosignal Optimization: Hydrogel-based Cell Biosensor
Hardware Cycle 2 for Improving User-Friendliness and Safety
Hardware Cycle 3 for Scalability and Storability
References
- [1] Delbrassinne, L., Andjelkovic, M., Rajkovic, A., Dubois, P., Nguessan, E., Mahillon, J., & Van Loco, J. (2012). Determination of Bacillus cereus Emetic Toxin in food products by means of LC-MS². Food Analytical Methods, 5, 969-979.