Study On Environmental Analysis Method Of Aggregation-Induced-Emission Guest Functionalized Metal-Organic Coordination Polymers(AIE@MOCPs)

In recent years,with the increase of population and the development of industry,a variety of exogenous emerging pollutants are continuously imported into the environment along with human production and living behavior,which has made the carrying capacity of the ecosystem decline.In the long run,it will pose a great threat to the stability and service function of the ecosystem and biological health.Therefore,it is necessary to develop highly sensitive,high spatio-temporal resolution environmental analysis and detection platforms for emerging pollutants or microbial pollution markers in the environment.With the combination and development of coordination chemistry and supramolecular chemistry,metal-organic coordination polymers(MOCPs)have attracted great attention.First of all,due to the diversity and designability of metal ions and ligands,the optical properties of MOCPs show great adjustability.Secondly,due to the self-assembled encapsulation properties of MOCPs,guests with suitable optical properties are readily to be introduced into the host MOCPs to obtain the functionalized materials that inherit the properties of hosts and guests,which is of significance to construct sensor arrays with multiple optical sensing units,to improve the performance and reliability of the analysis method,and to broaden the design idea of sensing strategy.Based on the background,firstly,we selected tetraphenylethylene derivatives with aggregation-induced emission(AIE)as the guest to obtain functionalized lanthanide metal infinite coordination nanoparticles(AIE@Ln-ICPs).Based on the theoretical study,the time-resolved fluorescence response(TRF)of sensitized Eu³⁺and the aggregation induced emission(AIE)of the guest were selected as the main sensing elements of the sensor array.Through the design of metal coordination,a pH-regulated fluorescent sensor array was constructed,which realized the pattern recognition and systematical analysis of three families of antibiotics(sulfadiazine,flumequine and oxytetracycline)and three kinds tetracyclines(oxytetracycline,tetracycline and doxycycline).In addition,benefitting from the anti-ACQ effect of AIE@Ln-ICPs on test papers,through recognizing and differentiating the fingerprints stemmed from the obvious fluorescence color changes on test paper,a low-cost and high-throughput paper-based sensor array was constructed which also enabled the pattern recognition and systematical analysis of tetracyclines in real water samples.Finally,two fluorescent molecules,one with AIE effect and one with ACQ effect were selected and encapsulated to obtain AIE/ACQ guests functionalized metal organic coordination polymers(AIE/ACQ@MOFs).Through regulating the metal coordination,a double ratiometric fluorescence method was successfully established on three fluorescence signals changes,which realized ATP(a biomarker of microbial contamination)analysis with high reliability.Furthermore,combining the apparent fluorescent color changes during the stimulus response with a color recognition and processing application installed on smart phones,point-of-use analysis for ATP was realized.Moreover,we successfully monitored the growth of Pseudoanabaena using ATP as a biomarker.In this paper,by fully exploring the metal coordination interaction,different responses of metal organic coordination polymers towards emerging pollutants or important markers were regulated.At the same time,a variety of environmental analysis methods have been developed and were integrated with test papers,smart phones and etc.,which not only provides the possibility for the improvement of spatial-temporal resolution in environmental field analysis,but also is of extensive application prospects in environmental emergency rescue or management and daily environmental monitoring by Environmental Protection Department.The article is divided into four chapters as follows:Chapter 1.OverviewFirstly,in this chapter,MOCPs materials with single luminescent response in environmental analysis were systematically summarized,and then the key issues and challenges may encounter in their development were proposed.Next,we introduced functionalized MOCPs materials with multiple luminescent responses.Although the reported analysis method based on ACQ@MOCPs with ratiometric response can effectively improve their analytical performance,their practical application is still limited.Taken the anti-ACQ effect of the novel aggregation induced emission(AIE)molecules into consideration,we next summarized the luminescent behavior of AIE molecules,and the applications of AIE functionalized MOCPs(AIE@MOCPs)in environmental field.Finally,the future development of AIE@MOCPs materials in environmental field was prospected,which is of great significance.Chapter 2.A pH-Regulated Sensor Array Based on H₄TCPE@Eu/AMP ICP:Towards Systematical Analysis of Environmental AntibioticsIn this study,1,1,2,2-tetrakis(4-carbonylphenyl)ethylene(H₄TCPE)with AIE effect was selected as the guest,and Eu/AMP ICP,an infinite coordination polymer with flexible and variable structure was used as the host to obtain functionalized infinite coordination polymers with AIE effect H₄TCPE@Eu/AMP ICP.After analyzing the molecular structures of different antibiotics,we studied the antenna effect between the antibiotics and metal ions in the host and the photo-induced electron transfer between the antibiotics and the guest.Then,the time-resolved fluorescence response(TRF)from the sensitized hosts and the unique aggregation-induced emission(AIE)fluorescence from the guest were selected as the main sensing elements to construct a sensor array.In order to further improve the analytical performance of the sensor array,pH was set as the extended response elements.By the rational regulation of metal coordination interaction,various fluorescent signal responses generated by three types of antibiotics(sulfadiazine,flumequine and oxytetracycline)with structural differences were recorded,and the pattern recognition and systematical analysis of environmental antibiotics were successfully realized using the principal component analysis(PCA)method.Chapter 3.H₄TCPE Guest Functionalized Infinite Coordination Polymers Based Sensor Array and Its Fingerprinting on Test Papers:Towards Point-of-Use Systematical Analysis of TetracyclinesBased on the study above,we found that tetracycline antibiotics with?-diketone group and hydroxyl group not only can effectively sensitize the fluorescence of Eu³⁺in the H₄TCPE@Eu/AMP ICP,but also can quench the fluorescence of H₄TCPE due to the“reductive photo-induced electron transfer”,which simultaneously led to the dual responses from the guest and the host of the H₄TCPE@Eu/AMP ICP.In this work,we further used the above-mentioned H₄TCPE@Eu/AMP ICP sensor array to systematically identify and analyze three tetracycline antibiotics(oxytetracycline,tetracycline and doxycycline)with structural similarities.In addition,with the excellent“anti-ACQ”characteristics of H₄TCPE@Eu/AMP ICPs on the papers and the different fluorescence color changes caused by the ratiometric fluorescent signal changes,a test paper sensor array was further developed.With the assistance of smart phone color recognition applications,based on the fingerprints of the test papers,the point-of-use systematical identification and analysis of tetracyclines in actual samples can be realized.Chapter 4.A Double Ratiometric Fluorescence Method and its Visual Analysis towards Microbial Pollutant Adenosine Triphosphate Based on AIE/ACQ@ZIF-8-like NanoflowerIn order to further expand the applications of AIE functionalized metal organic coordination polymers in the field of environment,two guests exhibit opposite fluorescence characteristics at different emission wavelengths(which are referred as ACQ guest and AIE guest)were introduced into non-lanthanide metal organic coordination polymers zeolite imidazole framework(ZIF-8)to obtain AIE/ACQ@ZIF-8-like nanoflowers.Through regulating the competitive coordination between ATP and the ligands with Zn²⁺,the structure of AIE/ACQ@ZIF-8-like nanoflowers altered.With the above changes,the confinement of the host disappeared,and triple fluorescence signal changes generated from the two guests(ME,AIE,ACQ),which can realize the double ratiometric fluorescence analysis towards ATP.In addition,during the above stimulus response process,the“turn-on”of ACQ guest and the“turn-off”of the AIE guest led to the fluorescence color change,which can also realize the visual analysis of ATP with the help of color recognition application on smart phones easily.Meanwhile,the above method can be applied for the dynamic monitoring of intracellular ATP,which can serve as a biomarker for the growth of Pseudoanabaena and is expected to be utilized for the early warning of harmful algal blooms.