| 초록 |
A portable, highly sensitive and selective phage-based electronic nose towards explosives is designed using computationally guided experimental genetic engineering. Big database for 8,000 tripeptides with nine volatile organic compounds belonging to three chemical classes is established to investigate unique chemical affinity. With the help of first principles density functional theory calculations, we unveil the underlying sensing mechanism that even the partial difference in genetic sequences of peptides demonstrates unique optical properties, as both aromatic and aliphatic molecules are attached. With high-throughput computational screening and binding energy score program we identify promising peptides, enabling bacteriophage based electronic nose to detect specific explosives with outstanding sensitivity and selectivity. Density functional theory calculations show distinct electronic bandgap redshift with varying peptide, inciting that the peptide sequence is the key descriptor for the chemical affinity toward the explosive molecules, thus the molecules can be easily identified with appearing colors of the phage bundles. The computational prediction is validated using in-vitro experiments with multiarray of genetically modified phages of five selected tripeptide sequences (AHW, WAW, WHA, WHW, WWW) and wild-type phages. Classification success rates from hierarchical cluster analysis very consistently agree the computational outcomes on the electronic nose performance. Our result elucidates the fundamentals for selective and efficient optical biosensor generated from genetically engineered phages, and their ability of distinguishing not only the explosives in different, but also in same chemical classes. Thus, the design principle proposed in this study provides guidelines for the construction of practical electronic nose. |
