Long-term stability study of botulinum toxin detection with AlGaN/GaN high electron mobility transistor based sensors

The long-term stability of antibody-functionalized, Au-gated AlGaN/GaN high electron mobility transistors for detecting botulinum toxin is reported in this study. The botulinum toxin sensor, which initially showed good data reproducibility and recyclability, was repeatedly tested over a 9-month period. The botulinum sensor was packaged and stored in phosphate buffered saline (PBS) at 4 °C in a refrigerator for long-term storage. The sensor was tested over time at room temperature and we found sensitivity losses of 2%, 12% and 28% after 3, 6 and 9 months, respectively. These results clearly demonstrate a significant step towards the realization of electronic detection of biomolecules by field-deployed sensor chips based on AlGaN/GaN HEMTs.