The Study Of Fluorescence Sensors Based On Tripolythiophene And Phenothiazine Derivatives

With the development of industry,many metal ions have been discharged into the environment,which eventually accumulate in the human body and harm human health.Fluorescence detection method is widely used because of its advantages of simple operation,high sensitivity and cheap equipment.In this thesis,four kinds of fluorescence sensors were designed and synthesized based on phenothiazine and tripolythiophene fluorophores.These sensors have good selectivity,strong anti-interference ability,high sensitivity and short response time.Finally,some practical applications were studied.Specific work has the following several aspects:?1?A new phenothiazine-based fluorescence sensor PPM was successfully designed and synthesized for detect Hg²⁺.The sensor based on the ICT sensing mechanism shows high selectivity,high sensitivity to Hg²⁺?detection limit is 12.5 n M?,strong anti-interference and fast response time in?DMSO/H₂O=1:3,V/V?solution.After adding Hg²⁺,the blue fluorescence at 455 nm was weakened,while the green fluorescence at 528 nm was enhanced,showing a ratio-type fluorescence on response.It is important to use PPM to detect Hg²⁺in seafood with good accuracy and precision.Importantly,PPM was successfully employed for highly selective detecting and imaging of Hg²⁺in living cells,as well as on paper/TLC-based“naked-eye”colorimetric assay.?2?A novel phenothiazine-based acylhydrazone fluorescent sensor was designed and synthesized,which can be applied to the detection of Cu²⁺in environmental water samples.In this study,It was found that adding Cu²⁺in the solvent?DMSO/H₂O=1:3,V/V?could quench the fluorescence of the sensor PN and not affected by other ions,it was found that,the sensor had a high selectivity to Cu²⁺,was not disturbed by the general metal ions.It has high sensitivity?detection limit of 0.179?M?,short response time and good reversibility for Cu²⁺detection.The complexation mechanism of PN and Cu²⁺binding constant of 1:1 was proposed by Job's plot,and the mechanism was well verified by ¹H NMR,HR-MS and FE-IR.Sensor PN could serve as a cost-effective solid-state sensor for immediate,convenient and“naked-eye”colorimetric detection of Cu²⁺in environmental samples.In addition,sensor PN has high accuracy and precision for the detection of Cu²⁺in water samples,which broadens the application range of this sensor.?3?A novel terthiophene-derived colorimetric and fluorescent dual-channel sensor termed TTA was designed and synthesized.The sensor TTA showed a significant fluorescence“turn-on”response to Fe³⁺and obvious fluorescence turn-off response to Cu²⁺with some good features including chromogenic reaction,high sensitivity and selectivity,ultrafast response time,high reversibility,wide p H working range along with recognition mechanism of the sensor were investigated by Job's plot,¹H NMR titrations,FT-IR and HR-MS spectra.Moreover,the sensor was employed to rapidly and visually determine Fe³⁺and Cu²⁺in water based on TTA-based paper test strips and solid silicagel with good results.?4?A novel fluorescent sensor TTB based on terthiophene derivative was designed and synthesized.The results show that the sensor can specifically recognize Hg²⁺without interference from general metal ions.The detection limit is 2.349×10^-7M,and the detection of Hg²⁺can be completed within one minute.In addition,Hg²⁺in water can be detected intuitively through filter paper containing fluorescent sensor TTB.