Synthesis And Properties Of Fluorescent Probe Based On Bis-rhodamine For Iron(?) Ion And Cellular Imaging

In the earth crust, the second reserve of metal element is iron. Iron is also one of the most important essential trace elements in living cells, which is inextricably linked to the maintenance of the organism's life activity and health. The deficiency or overload of Fe3+ in human and animal bodies would result in various disorders and harmfully impact on the health of living body subsequently. In addition, Fe3+ has severe effects on the production and quality of crops and water bodies via various industrial and agricultural activities. Hence, it is still a great significance and value to develop efficient method for the detection of Fe3+ to meet the needs of biological and environmental application.In this work, based on the principle of the ring-opening of rhodamine derivatives with spirolactam structure induced by specific metal ions can give rise to strong fluorescence emission and a remarkable color change for naked-eye, we have developed two novel turn-on fluorescent probes based on bis-(rhodamine) for Fe3+. The work was carried out as follows: 1. The fluorescent probe Rh-1 for trivalent ferric ion(Fe3+) was synthesized based on the reaction of terephthaloyl chloride and rhodamine lactam derivatives. It was studied that the various factors, such as solvent, p H, reaction time, interfering ion, affected the selective response of Rh-1 to Fe3+ and the proposed binding mechanism between Rh-1 with Fe3+. And an approach was developed for the detection of trace amount of Fe3+ based on Rh-1 as fluorescent probe. The linear range covered from 1.0×10-7 mol/L to 2.6×10-5 mol/L, and the detection limit was found to be 2.31×10-8 mol/L. the chemosensor Rh-1 has been used to monitor Fe3+ level in real samples and image Fe3+ in SGC-7901 cells with satisfying results.2. The fluorescent probe Rh-2 for trivalent ferric ion(Fe3+) was synthesized based on the reaction of succinyl chloride and rhodamine lactam derivatives. It was studied that the various factors, such as p H, reaction time, interfering ion, affected the selective response of Rh-2 to Fe3+ and the proposed binding mechanism between Rh-2with Fe3+. And an approach was developed for the detection of trace amount of Fe3+ based on Rh-2 as fluorescent probe. The linear range covered from 3.0×10-7 mol/L to 1.4×10-5 mol/L, and the detection limit was found to be 1.24×10-8 mol/L. the chemosensor Rh-2 has been used to monitor Fe3+ level in real samples and image Fe3+ in PC-12 cells with satisfying results.