Fluorescence Visualization Investigation Of Aggregation-induced Emission Surfactants Complexes

Surfactant-based system plays an important role in scientific researches and industrial processes,which has attracted a lot of attention.Actually,the complexed systems based on surfactants have been widely used in practical applications.A plenty of traditional measurements have been developed for the investigations of these systems.More attention is paid to the fluorescence visualization method because of its advantages of high sensitivity,easy operation and rapid response.However,most fluorescence visualization methods are used to study the surfactant-based systems by the fluorescence property of invasive dyes,rather than the fluorescence property of surfactant itself.Hence,it's conceivable that a fluorescent surfactant can directly study the interactions of surfactant-based systems.It is noting that the aggregations of high concentration of traditional surfactants cause fluorescence quenched.In order to resolve the ACQ problem,our group designed and synthesized two types of AIE-active surfactants:anionic tetraphenylethene-cored sodium dodecyl sulfonate(TPE-SDS)and cationic tetraphenylethene-cored dodecyl trimethyl ammonium bromide(TPE-DTAB).In this work,AIE-active surfactant was used to study the fluorescent visualization interactions of surfactants and polymers,surfactants and bacteria,respectively.(1)The addition of different concentrations of anionic TPE-SDS to the constant concentration of chitosan solutions had been used to investigate the interactions between surfactants and polymers.The result demonstrated that the fluorescent images in different stages coincided with the interactions stages of surfactants and polymers.Moreover,the interactions between TPE-SDS and uncharged polyethylene oxide(PEO)were also used to verify the generality of fluorescent visualization method.It is concluded that the AIE-active surfactant can be used to realize the fluorescence visualization of the interactions between surfactants and polymers.The investigation provides other researchers a new opportunity to explore the interactions of different surfactant and polymer systems.(2)Under the same condition,Gram-negative E.coli was incubated with anionic TPE-SDS and cationic TPE-DTAB,respectively.With the addition of propidium iodide(PI)to the mixtures solution,the effect of surfactant on bacteria was evaluated.The results show that TPE-DTAB has killed 78.6%of E.coli.In contrary,anionic TPE-SDS have no obvious antibacterial activity.Due to the AIE property of the used surfactant,the interactions of surfactant and bacteria was visualized.In addition,TPE-DTAB/TPE-SDS with a ratio of 5:1 enhances the bacteria killing efficiency from 78.6%to 99.4%.This is the first time to verify the antibacterial mechanism of cationic surfactant and realize the fluorescence visualization of the...