Organic-Inorganic Hybrid Nanomaterials For Chemical Sensors

One good sensor using to detect pollutant should have good selectivity,high sensitivity,recyclable and low toxicity,while the small organic molecule fluorescent sensors have high toxicity,poor water solubility and unrecyclable.In this paper,aiming to solve these problems,the fluorescent sensors based on naphthalimide compounds were combined with nanoparticles such as Fe₃O₄@SiO₂ nanoparticles,Fe₃O₄@Meso-SiO₂ nanoparticles,and bcc-Fe-Au dumbbell nanoparticles.The synthesized organic-inorganic hybrid fluorescent sensors have good selective response to Fe3+ with fluorescence quenching and Hg2+ with fluorescence improving in water and cells,respectively.Both sensors can be recycled using external magnetic field.With adding EDTA to the detecting systems,ions can be removed from the complexes and their fluorescence probing ability recover,which means these fluorescence probes could be reversed and reusable.In order to realize pollutants portable detection in a large scale and high concentration,nanogenerator can be used in the research of the fluorescent sensors.In this paper,aiming to improve the output perfermance of nanogenerator,the piezoelectric PVDF-HFP nanofibers doped with Au nanoparticles.By doping,the piezoelectric phase mounts in PVDF-HFP have improves and the mechanical property of Au-PVDF-HFP also strengthen.Using the Au-PVDF-HMP nanofibers to prepare nanogenerator,the output voltage and current both has improved significantly.If this nanogenerator can be combined with hybrid fluorescent sensors to built fluorescent detection divices,they could have a board applicaition prospect and realize portable and real-time detection.This paper involves in organic chemistry,inorganic chemistry and materials science.Combined with the basic research of supramolecular chemistry.the main work can be described as follow:Two kinds of organic-inorganic hybrid fluorescent sensors for detecting iron ions and mercury ions were prepared.Both systems have low toxicity,high water solubility and can be recovered.Nine new naphthalimide compounds were designed and synthesized.Their structural characterization was given.This is the basic step to prepare hybrid fluorescent sensors.Silica coated magnetic nanoparticles,mesoporous silica coated magnetic nanoparticles and bcc-Fe-Au dumbbell nanoparticles were prepared successfully.This is the key step to prepare hybrid fluorescent sensors.The various parameters which affect the size and uniformity of the nanoparticles during the preparation were discussed.Finally,the optimization of the preparation process was realized.Based on the principle of "on-off",three kinds of organic-inorganic hybrid nanomaterials（L1-Fe₃O₄@SiO₂,L2-Fe₃O₄ @SiO₂ and L3-Fe₃O₄@SiO₂）were prepared.By studying and analyzing the fluorescence response and selectivity of the three hybrid nanomaterials,we found that in the solution of CH3CN/H2O 1:1（HEPES buffer,pH 7.36）,L2-Fe₃O₄@SiO₂ could be selectively used to detect Fe3+ at low concentration through effective coordination effect,and the experiment results also proved that the coordination process is reversible and recycled.Combined with the superparamagnetism of ferroferric oxide nanoparticles,the hybrid nanomaterials could be expected to realize the recognition and separation of Fe3+ at the same time.L2-Fe₃O₄@SiO₂ is also successfully used to detect Fe3+ in living HeLa cells,which shows its great potential in bioimaging detection.L3-Fe₃O₄@SiO₂ could be used to the detect and separate Fe3+ in aqueous solution.Based on the principle of "off-on",three kinds of organic-inorganic hybrid nanomaterials（L4-Fe₃O₄@Meso-SiO₂,L5-Fe₃O₄@Meso-SiO₂ and L6-bcc-Fe-Au）were prepared.By studying and analyzing the fluorescence response and selectivity of the three hybrid nanomaterials,we found that in the solution of C2H5OH/H2O 1:2（HEPES buffer,pH 7.42）,L5-Fe₃O₄@Meso-SiO₂ could be selectively used to detect Hg2+ at low concentration through effective coordination effect,and the experiment results also proved that the coordination process is reversible and recycled.By connecting to the mesoporous nanoparticles,the selectivity and sensitivity of the fluorescent sensors were significantly improved,while the limit of detection was reduced.Combined with the superparamagnetism of ferroferric oxide nanoparticles,the hybrid nanomaterials could be expected to realize the recognition and separation of Hg2+ at the same time.L5-Fe₃O₄@Meso-SiO₂ is also successfully used to detect Hg2+ in living HL60 cells,which shows its great potential in bioimaging detection.L6-bcc-Fe-Au could be used to the detect and separate Hg2+ in aqueous solution.The results have shown that the organic-inorganic hybrid fluorescent sensors not only have the property of the fluorescent probe,but also keep the properties of nanoparticles.Therefore,the hybrid nanomaterials could have potential applications value in the fields of biology and environment.Aiming at the low output performance of nanogenerator,the output voltage of the BaTiO₃/PDMS composite PENG with different volume ratio of evenly distributed BaTiO₃ cubes was studied,and found that there exists an optimal volume ratio（46%）of the BaTiO₃ cubes at which the PENG can output the highest voltage.Based on this result,a new organic-inorganic hybrid Au-PVDF-HFP nanofiber was designed and synthesized.Since the doped-Au can improve the amount of piezoelectric phase of PVDF-HFP,the new nanomaterial was used as electrode materials to build Au-PVDF-HFP nanogenerator.the output voltage and electricity of Au-PVDF-HFP nanogenerator both greatly improved.