Biosensor for caffeine detection using Drosophila gustatory receptor-derived peptide

High-dose caffeine intake by humans may trigger a series of adverse reactions, making it necessary to establish a rapid, simple, reliable, and highly sensitive method for detecting and analyzing caffeine. Previous research demonstrated that the gustatory receptor DmGr66a of Drosophila melanogaster could recognize caffeine. In this study, the binding sites of DmGr66a for recognizing caffeine were identified by modeling DmGr66a and using molecular docking technology, and ultimately four gustatory receptor-derived peptides (GRP) were designed. Subsequently, a GRP biosensor for identifying caffeine was designed and fabricated, which was capable of detecting caffeine at a concentration as low as 10 pM, two orders of magnitude lower than the lowest detection limit reported so far. And the sensor could detect caffeine with high sensitivity and selectivity. Meanwhile, it exhibited excellent performance in terms of operation and storage stability, and could accurately detect caffeine in real beverage and serum samples. Therefore, the GRP sensor could be applied to the real-time monitoring of caffeine in beverages and serum, and find applications in the food and medical industries.