Study Of Fluorescent Probe For Cations Based On Rhodamine-B

The advantages of molecular fluorescent Probes for sensing can be summarized:high sensitivity of detection down to the single molecule,"on-off",switch ability, subnanometer spatial resolution and submillisecond temporal resolution,observation in situ,remote sensing by using optical fibres,et al,and already has played an important role in metal cations,nucleic acids,immune cells and testing.The Rhodamine dyes have excellent PhotoPhysics and Photochemistry properties such as high molar extinction coef-fieient,high stability against light and chemical reactions,and high fluorescence quantum yields,etc.Therefore,the studies on fluorescence molecular probes for cations based on Rhodamine dyes are attracting many people's attentions.A new kinds of Rhodamine B-based Fluorescent probes RBS1 and RBS2 are designed, synthesized and structural characterized for the selective detection of Hg²⁺ based on its thiophilicity in DMF/H₂O(v/v=1:1) solution.They feature brightness red emission in the presence of Hg²⁺ with the fluorescent detection limit for Hg²⁺ in aqueous media being ppb levels and exhibit excellent Hg²⁺-specific luminescence enhancement over various competitive cations,including alkali and alkaliearth,the first-row transition metals and heavy metals.By immobilizing RBS3 to the mesoporous SBA-15-NH₂,a highly selective and sensitive chemosensor toward mercury cations in aqueous solution is achieved.RSA could quantitative determinate mercury cations at ppb level in the practical environmental media,suggesting the the possiblity for real-time quantitative detection of Hg²⁺ and the convenience for potential application in toxicology and environmental science.Based on "off-on"fluorescent switch principle,two fluorescent probes have been designed and synthesized.RBO1 and RBO2 showed can selectively recognize Cr³⁺ in water through the emission spectrum.The coordinations of RBO1 and RBO2 with Cr³⁺ are reversible process through RBO1 and RBO2 with Cr³⁺ and EDTA tiration esperiments.The fluorescences image that RBO1 and RBO2 with Cr³⁺ in HeLa cells showed RBO1 and RBO2 to be acted as fluorescent probes for monitoring Cr³⁺ in living cells.