设计合成了甲苯2, 4-二异氰酸酯桥联纳米Fe3O4和罗丹明6G的PEG基荧光探针试剂。 并用红外光谱、 热重分析、 透射电镜方法进行了表征。 该探针与Fe3+结合显示红色, 可以作为一种裸眼检测的试剂用于溶液中Fe3+的检测。 该探针对Fe3+具有很强的选择性和高的灵敏性, 荧光滴定法研究表明, 对Fe3+的检测的灵敏度达到l.5×10－9mol·L-1, 即使溶液中在Fe2+, Mn2+, Ni2+, Y3+, Eu3+, Ce3+, La3+, Pr3+, Cd2+, Cr3+, Sm3+, Cu2+和Zn2+等共存的条件下, 该荧光探针能够高选择的识别出Fe3+, 检测不受干扰。 而且该探针分子能够穿透HeLa细胞检测细胞内的Fe3+, 对细胞有较好的标记功能。 该荧光探针试剂有很高的水溶性, 且合成过程简单, 易于操作。

A higher selective and sensitive probe for the detection of Fe(Ⅲ) in aqueous media was made using 2,4-Diisocyanatotoluene (TDI) as a bridge to couple Fe3O4 nanoparticles(NPs) and Rhodamine-6G hydrazide. The characterization of composite materials with Infrared spectra(IR), Thermal Gravimetric analysis(TGA) and Transmission Emission Microscopy(TEM) points to the graft of Rhodamine-6G hydrazide onto the surface of the Fe3O4. The obvious color change of the probe solution from light grey to pink upon the addition of Fe3+ demonstrated the probe could be used for “naked-eye” detection of Fe3+ in water at pH 7. The presence of 1 equivalent (10μmol·L-1 μm) of each of these metal ions, including Mn2+, Ni2+, Y2+, Eu3+, Ce3+, La3+, Pr3+, Cd2+, Cr3+, Sm3+, Fe2+, Cu2+and Zn2+ ions, did not demonstrate any obvious fluorescence change of the probe water solution, which confirmed the probe was a probe with remarkable selectivity for Fe3+. And the fluorescence images of HeLa cells in physiological solutions after incubation with Fe3+ and then further incubated with the probe leading to a strong intracellular fluorescence, which suggested the probe could penetrate the HeLa cell membrane and could respond to Fe3+ in intracellular within living cells.