The Fluorescent Probe Using Trimethyl Lock Strategy: Design, Synthesis And Application

Typical analytical methods used for quantification of biological thiols or metal ions often require complicated sample preparation steps,rigorous experimental conditions, sophisticated instrumentation, and well-trained individuals. Thus, current research has been focused on fluorescent methods, because of their low cost, simplicity, sensitivity,selectivity, rapid response, and high spatial resolution via microscopic imaging. In this paper, the research mainly consists of the following three parts.Part 1: A novel turn-on fluorescent probe TML-P1 based on trimethyl lock for the detection of glutathione has been developed. The probe can selectively and sensitively detect glutathione over other biothiols including cysteine/homocysteine in solution, and the limit of detection was calculated to be 26 nM. Probe TML-P1 displays obvious response for glutathione in the pH region of 6.8–8.0. Furthermore, the probe has been successfully used to detect glutathione in living cells. Due to its sensitivity and selectivity, the proposed chemodosimeter can be used to detect glutathione at physiological levels.Part 2: A novel fluorescent probe TML-P2 based on trimethyl lock forthe detection of glutathione and cysteine/homocysteine has been developed.We have demonstrated the design and application of a platform to effectively measure cysteine/homocysteine and glutathione ratios using a dualfluorophore fragmentation strategy. Probe TML-P2 displays obvious response for glutathione and cysteine/homocysteine in the pH region of 7.2-8.0. The strategy described here introduces a novel fluorescent probe that could detection of glutathione and cysteine/homocysteine.Part 3: A novel turn-on fluorescent probe P3 for the detection of palladium has been designed. The probe can selectively and sensitively detect palladium in solution, and the limit of detection was calculated to be 11.4 nM.To demonstrate the potential application of the probe to detect various sources of palladium species, we tested whether it could respond to different initial oxidation states of palladium with various kinds of ligand. The results revealed that probe P3 remarkably responds to the different oxidation states of palladium. Furthermore, the probe was successfully used for fluorescence imaging of palladium in living cells. The current work provides a new mild and promising strategy for the detection of palladium species in biological and environmental systems.