In this research, specific molecular sensors are classified according to the type of receptor-cation interaction, that is ligand-metal interactions. Receptors are based on a multidentate protoporphyrin-appended pyridi...In this research, specific molecular sensors are classified according to the type of receptor-cation interaction, that is ligand-metal interactions. Receptors are based on a multidentate protoporphyrin-appended pyridine platform, which leaves at least a vacant coordination site for the incoming metal ions. A protoporphyrin-appended pyridine, 2,5-pyridine dicarboxyamidyl-8,13-bis(vinyl)-3,7,18,17-tetramethyl-21 H, 23 H-porphyrin(P-PTP), was designed and synthesized. Its application as potential fluoroionophore for recognition of cadmium and mercury ions is reported. P-PTP shows chelation-enhanced fluorescence effect with Cd(Ⅱ) and Hg(Ⅱ) via the interruption of photoinduced electron transfer (PET) process, which has been utilized as the basis of the fabrication of the metal ions-sensitive fluorescent chemosensor. The analytical performance characteristics of the proposed Cd(Ⅱ)- and Hg(Ⅱ)- sensitive chemosensors were investigated. It shows a linear response toward Cd(Ⅱ) and Hg(Ⅱ) in the concentration range of 1.0×10-3 to 1.0×10-7 M with a limit of detection of 1.0×10-7 M and 0.5×10-7M for Cd(Ⅱ) and Hg(Ⅱ), respectively. The chemosensor shows good selectivity for Cd(Ⅱ) over a large number of other transition metal ions, i.e., Cu(Ⅱ), Zn(Ⅱ) and mixed metal ions.展开更多
文摘In this research, specific molecular sensors are classified according to the type of receptor-cation interaction, that is ligand-metal interactions. Receptors are based on a multidentate protoporphyrin-appended pyridine platform, which leaves at least a vacant coordination site for the incoming metal ions. A protoporphyrin-appended pyridine, 2,5-pyridine dicarboxyamidyl-8,13-bis(vinyl)-3,7,18,17-tetramethyl-21 H, 23 H-porphyrin(P-PTP), was designed and synthesized. Its application as potential fluoroionophore for recognition of cadmium and mercury ions is reported. P-PTP shows chelation-enhanced fluorescence effect with Cd(Ⅱ) and Hg(Ⅱ) via the interruption of photoinduced electron transfer (PET) process, which has been utilized as the basis of the fabrication of the metal ions-sensitive fluorescent chemosensor. The analytical performance characteristics of the proposed Cd(Ⅱ)- and Hg(Ⅱ)- sensitive chemosensors were investigated. It shows a linear response toward Cd(Ⅱ) and Hg(Ⅱ) in the concentration range of 1.0×10-3 to 1.0×10-7 M with a limit of detection of 1.0×10-7 M and 0.5×10-7M for Cd(Ⅱ) and Hg(Ⅱ), respectively. The chemosensor shows good selectivity for Cd(Ⅱ) over a large number of other transition metal ions, i.e., Cu(Ⅱ), Zn(Ⅱ) and mixed metal ions.