Design And Synthesis Of Fluorescence Probes For Recognition And Imaging Of Hg²⁺ In Living Cells

Fluorescence probes possess the ability of selectively converting the related information of analysis object into easily measured fluorescent signal, achieving good selectivity, high sensitivity and real-time detection in situ etc. Therefore, the design of excellent fluorescence probes for studying the molecular and biochemical indicators of interests has been a hot topic in related fields. As one of the most toxic metal ions, the gathering of mercury ions in the human body will result in serious damages. Consequently, it's crucial to develop a novel method for accurate, fast and convenient detection of mercury ions in the environment and organisms. In this paper, on the base of research results in related research fields in recent years, two types of fluorescein derivatives probes for recognition and imaging of mercury ions in living cells are designed and synthesized.1. A novel fluorescence probe P1 is designed and synthesized by introducing alkyne functional groups into fluorescein. Taking advantage of the alkyne-philic of mercury ions, the interaction between mercury ion and alkyne functional group can result in the converting of fluorescein from the non-fluorescent spirocyclic form into the fluorescent open ring form, achieving enhanced fluorescence signal and realizing the selective detection of mercury ion. Spectroscopy experimental results show that probe PI exhibit high selectivity to Hg2+and is insensitive to pH. Mercury ion titration experiments indicate that the detection limit of probe P1 for mercury ion is 12.4?M, which is suitable for the quantitative detection and analysis of mercury ions. Cells fluorescence imaging experiments show that the probe can be applied to image mercury ions in living cells, thus providing a visual detection means for the early prevention and diagnosis of mercury ion-related diseases.2. Another novel fluorescence probe P2 is designed and synthesized by introducing hetero carbon chain, methyl pyridine and coumarin fluorophore into the fluorescein. Theoretically, Cu2+ and Hg2+ will occupy two different complexing sites, resulting in the different fluorescent signal, so as to achieve the purpose of simultaneous identification for Cu2+ and Hg2+. Experimental results show that the probe P2 only response to mercury ions to a certain extent. In order to achieve the desirable recognition results, further optimization of the probe's structure is needed.