Construction Of Functionalized Polydiacetylene Liposome And Its Application In Detection

Conjugated polymers have more and more applications in the field of sensors due to their optical signal amplification characteristics.Among them,the polydiacetylene(PDA)material with an ene-yne conjugated skeleton can not only produce color changes visible to the naked eye under external stimulation,but also produce a phenomenon of fluorescence enhancement from no fluorescence to red fluorescence.This kind of polydiacetylene material with dual detection advantages has the advantages of fast,sensitive and simple operation during analysis and detection,so it is widely used in the field of biological and chemical sensors.Polydiacetylene-based chemical and biosensors have been reported continuously since the discovery of polydiacetylene materials,and their analytes range from chemical analytes including metal ions,organic solvents,surfactants,hydrocarbons to biological analyte including viruses,proteins,bacteria and etc.But we believe that with the passing of time and technology,there will be a variety of analytes that need to be tested.Therefore,improving the sensitivity of the sensor based on polydiacetylene,ensuring its specificity for the analysis target,and expanding its detection range are our most important and most difficult tasks at present.In this paper,based on the demand for sensors in biological and chemical analysis,two new polydiacetylene liposome sensing systems were successfully constructed by designing and synthesizing two functionalized diacetylene monomer,which successfully achieved rapid,efficient and specific analysis of heavy metal ions lead ions and cationic surfactants.At the same time,it also provides new methods and ideas for polydiacetylene materials in the field of biological and chemical sensors.1.An orotic acid-modified polydiacetylene liposome sensing system was successfully constructed,and a fast and specific analysis of lead ions was achieved through complexation between head group with lead ions.By rational design and synthesized,an orotic acid(OA)group was introduced at the carboxyl group of the head group of the 10,12-pentadecanediyne acid(PCDA)of the diacetylene molecule,then an orotic acid-modified diacetylene monomer was synthesized.The polydiacetylene liposome(PDA-OA)sensing system was prepared by ultrasound-assisted dispersion method with two monomers PCDA and PCDA-OA in a molar ratio of 9:1.Through experiments such as titration experiments and selective tests,it was proved that the prepared PDA-OA sensor system successfully achieved colorimetric and fluorescent detection of lead ions in pure water,and had good specificity and detection limit.The detection limit can as low as 0.25 ?M.2.A 3,4-dihydroxyphenylacetic acid modified polydiacetylene liposome sensor was successfully constructed,which realized the detection and differentiation of four cationic surfactants(CS).In this study,we modified the diacetylene monomer PCDA with the 3,4-dihydroxyphenylacetic acid group to obtain the diacetylene monomer PCDA-BA,and then a functional polydiacetylene liposome sensor(PDA-BA)was prepared from two monomers,PCDA: PCDA-BA,in a molar ratio of 9:1.Titration,selectivity and other experiments prove that the PDA-BA sensor we prepared realizes the recognition and differentiation of several cationic surfactants,and has good specificity and low detection limit.By consulting the literature,it is known that the detection limit of the system for the four CS is lower than the effective toxic concentration of CS to aquatic organisms in water phase in international standards.