Preparation Of AIE Functional Mesoporous Silica Material And Its Application In Sensing And Drug Controlled Release

Mesoporous silica nanoparticles?MSN?possess some unique properties,such as pores with discrete but adjustable diameters,modifiable surface properties,regular mesoporous structures,which ensure their wide applications in the adsoprtion,sensors,catalysis,drug delivery.In particular,MSN as an ideal optical sensing support materials can allow for the optical groups to be anchored onto the silica matrix for the construction of functionalized MSN by the co-assembly and subsequent modification pathways,so as to expect the high stability and matrix protection of the fluoropHores.Moreover,the fluorogens with aggregation-induced emission?AIE?can emit strong fluorescence in the state of aggregation,which provides an elegant alternative to overcome the pHenomenon of aggregation-caused quenching?ACQ?effects.Therefore,it is of great significance to combine AIE molecules with MSN to prepare favorable fluorescent probes and act as the drug controlled release materials.In this thesis,AIE functionalized mesoporous silica nanoparticles have been prepared and applied for the sensing and drug controlled release.On one hand,AIE organosilicas precursors were synthesized by the silanization modification consisting of the AIE organic molecules and condensable silane molecules.Furthermore,these organosilicas precursors were immobilized onto the surface of MSN by post-grafting method.On the other hand,the so synthesized AIE-functionalised mesoporous silica nanoparticles were applied for the fluorimetric sensing detection of copper ions and drug release control release.?1?A fluorescent nanoprobe was fabricated with AIE-functionalised mesoporous silica for the sensitive detection of Cu?II??Chapter 2?.A organic fluorescent molecule of methylenemalononitrile compound?defined as MC?was synthesized by the Schiff-bases reaction of N-?4-formylpHenyl?carbazole with diaminomaleonitrile.Moreover,AIE luminogen functionalized mesoporous silica nanoparticles were synthesized using the MC molecule-derived organosilicon precursor?MC-Si?that were immobilized on the surface of mesoporous materials.The N atom at C=N of MC molecules there can specifically coordinate and chelate with Cu²⁺ions.A highly efficient enhanced-fluorescence emission of the MC-MSN was thereby achieved for the highly sensitive fluorescent analysis of Cu²⁺ions.Besides,MC-MSN probes were reused by the suitable chemical treatment route?i.e.,adding EDTA?.?2?A drug controlled release system has been constructed using AIE functionalized mesoporous silica materials?Chapter 3?.Herein,on the one hand,a maleimide organic fluorescent molecule with AIE function?defined as MN?was synthesized for the further silanization modification to produce the organosilicas precursors MN-Si consisting of the MN organic molecules and condensable silane molecules.Moreover,they were coated on the surface of the dye-loaded mesoporous silica material by grafting to yield the AIE functionalized mesoporous silica material MN-MSN.And rhodamine dye was used as a drug model reagent to be loaded into the pores of the mesoporous silica materials.On the other hand,the cyclodextrin molecule with the ability of coating MN-Si molecule and pH-responsive degration was attached to the surface of the MN-MSN to serve as pH-responsive gatekeeper for controlling the release of dye molecules from the pores.Subsequently,the AIE luminogen-functionalized mesoporous silica nanoparticles can release the dye molecule by controlling the pH stimulant.A drug controlled release system was thereby constructed with AIE functionalized mesoporous silica nanoparticles.The controlled release behavior of rhodamine molecules in the mesoporous silica pores was systematically studied in detail.