Design And Synthesis Of Fluorescent Probe For Antimony Detection

Dyeing and printing industry has been seriously restricted by the high concentration of antimony in the wastewater,so it is of significant importance to achieve the simple and sensitive detection of antimony in aqueous solution.However,the widely used method alwasy suffer from expensive equipment and complicated testing procedures.Fluorescent detection is one of the ideal method,but simple fluorescent probe for antimony has not been reported yet,so fluorescent sensor for antimony with simple structure and easy to synthesis is still needed.Combine fluorogen and functional groups together is a easy way to design fluorescent sensors.As reported by previous works,tetraphenylethylene(TPE)and pyrene are two kinds of fluorogens with special fluorescent properties.Meanwhile,o-hydroxyphenamine(IPH),a functional group with N/O atoms,can coordinate with antimony specifically,is an ideal functional group.Thus,in this thesis,TPE and pyrene are combine with functional groups IPH by Schiffbase reaction respectively to prepare antimony fluorescent sensors with high sensitivity,selectivity and specificity.The detail contents of the thesis are as follows:In the first part,fluorescent probe based on tetraphenylethylene were design and synthesized and applied in antimony detection.Fluorescent probes TPE-IPH and TPE-2IPH for antimony were prepared by amino modified TPE and salicylaldehyde.1H-NMR and 13C-NMR were used to characterize their chemical structures,scanning electron microscope(SEM was used to study their surface morphology;ultraviolet absorption spectrometer(UV),fluorescence spectrometer(FL)and dynamic particle size meter(DLS)were used to measure their physical/chemical stability,optical property and antimony detective property,respectively.The results showed that both of TPE-IPH and TPE-2IPH presented perfect physical/chemical stability,they could exhibit typical AIE property in the mixture of THF and water,and their emission was greatly boosted with the addition of antimony when the water fraction was 90%,Moreover,they could distinguish antimony with other cations well,which indicated it as a potential indicator for antimony with high selectivity and specificity.Mechanism studies showed that the rotation of IPH functional groups could anchored by the intramolecular hydrogen formed by N atom and-OH groups in IPH group under aggregated state,and then the coordination between IPH groups and antimony caused the enhanced aggregation of the probes and achieved the enhancement on emission of the detection system.In the second part,fluorescent probe based on pyrene was design and synthesized and applied in antimony detection.The fluorescent probe Py-IPH was prepared by aldehyde pyrene and o-hydroxyaniline.1H-NMR and 13C-NMR were used to characterize its chemical structures and UV/FL were used to measure its physical/chemical stability,optical property and antimony detective property.The results showed that Py-IPH also had good physical/chemical stability with specical aggregated emission in the mixture of THF and water.Compared to TPE-IPH and TPE-2IPH,Py-IPH displayed better fluorescent response to antimony ions,as well as the specificity and selectivity.Mechanism studies showed that the weak coordination between IPH functional group in Py-IPH and antimony could keep the chromophore of Py-IPH in regular arrangement in the detection system with 80%of water and achieve the enhancement of the mixture.In conclusion,simple and specific fluorescent probes for antimony were successfully prepared by the Schiff base reaction between fluorogen TPE/pyrene and functional groups IPH with N/O groups.The prepared probes presented perfect physical/chemical stability and displayed enhanced response to antimony in the mixture of THF and water.The change of the emission was demonstrated to be caused by the aggregation of the fluorogens owing to the coordination between functional groups IPH and antimony.