Synthese Of Peptide-based Fluorescent Probe For The Detection Of Cu²⁺ And H₂S In Water

Abstract:Because of their rapid response, high sensitivity, and excellent selectivity, small molecule-based fluorescent probes have wide applications in analytical chemistry and bioimaging. Their design and synthesis have attracted increasing attention and become a very active research field. Both copper ion and H2S are important substance in enviroment and organism, and their sensors often have their defects of poor water solubility and selectivity. In this thesis, two kinds of probes were designed and synthesis. The main contents are as follows:Taking tripeptide, Gly-Gly-His (GGH), as the recognition unit, and Trp as the signal unit, a Cu2+fluorescent porbe Trp-Gly-Gly-His (WGGH) was synthesized by using solid phase synthesis. Due to the conjugation of GGH towards Cu2+and quenching effect of Cu2+, WGGH can act a turn-off fluorescent sensor for Cu2+. The synthesized probe has the advantages of rapid response, excellent water solubility, wide detection window and high sensitivity. The fluorescent probe allows detection of Cu2+with a linear range of10-1000nM and a LOD (limit of detection) of3.5nM.By conjugating GGH to coumarin, a novel probe C-GGH was synthesized for the detection of Cu2+. This probe also has the merits of rapid response (less than1min), excellent water solubility and selectivity. high sensitivity. C-GGH has a dynamic range of1-20μM for Cu2+with a LOD of0.28μM. Furthermore, based on the high affinity of S2-to Cu(Ⅱ), the complex C-GGH-Cu2+was successfully used for the detection of H2S with a dynamic range of4-20μM and a LOD of0.47μM.Due to the excellent water-solubility and cellular permeability, probe C-GGH-Cu was utilized for real-time fluorescence imaging of intracellular H2S in live HeLa cells.