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Fabrication Of The Functional Micro/nano Materials And Their Applications In Environmental And Biological Analysis

Posted on:2017-11-11Degree:MasterType:Thesis
Country:ChinaCandidate:Y Y LiuFull Text:PDF
GTID:2381330590463675Subject:Applied Chemistry
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Micro/nano materials with excellent optical properties and good biocompatibility have been widely used in the field of environment,biology and energy,etc.However,the actual samples in environment and biology possess the characteristics of low concentration,complexity,instability that lead to the limitation of its applications in the actual analysis.Thus,to fabricate a novel functional micro/nano composite material with high sensitivity and good selectivity has important research significance.Based on this phenomenon,the composite film with strong adsorption properties was prepared by the modification of graphene,carbon nanotubes,precious metals and other materials to achieve the efficient removal and sensitive detection of antibiotic in water.Meanwhile,due to the complexity in biological systems,we manufactured a nanosensor with high sensitivity and selectivity for the detection of small biological molecules in cells.Specific studies included the following three aspects:1.Ultrathin/Ultralight Hybrid Porous Carbon Membranes and Their High Performance in Removing AntibioicsIn recent years,the abuse of antibiotics in medicine,agriculture and aquaculture has led to serious water pollution that threaten to human health and ecological safety directly.Thus,in order to ensure water security,a new kind of functional materials for efficient removal of antibiotics is needed.For this problem,we embedded activated carbon in the graphite oxide sheet to fabricate a novel functional porous composite carbon membrane?GO/AC?by vacuum filtration method and studied the adsorption properties to remove antibiotics from water.The results show that the composite film has features of large surface area,available transmission channels,great mechanical properties,more active sites and enhanced adsorptive capacity.The most important is that the production holds the advantages of greater removal efficiency of tetracycline hydrochloride?>99%?and large adsorption capacity?349.4 mg/g,p H = 7?and many reused times.We utilize the single molecule fluorescence detection technology to detect the TCH with low concentrations and the limitation was p M level.This provides a new treatment materials and testing tools for the antibiotics pollution of water.2.Ag NPs/CNTs-intercalated GO membranes for high-capacity enrichment and surface enhanced Raman scattering detection of antibioticDuring the above-mentioned study,we found that the water content of antibiotic residues in the environment are relatively low and difficult to achieve on-site testing.Surface-enhanced Raman spectroscopy?SERS?technique possess the ascendancies in simple technical operations,information-rich content,high sensitivity,without sample pretreatment and real-time on-site detection,etc.Based on the fabrication of high-performance SERS active nano-materials,we can achieve the detection at single-molecule level.Therefore,in this chapter,we uniformly dispersed Ag NPs on CNTs modified GO surface and insert its nanosheets by physical and chemical methods to prepare Ag NPs/GO-CNTs substrates with the abilities of both enrichment and enhancement of Raman spectroscopic signals,and combined with a portable Raman Spectrometer to detect residues of tetracycline hydrochloride in the environment.Wherein,the GO-CNTs and Ag NPs play the role of the enrichment of molecules and SERS enhancement,respectively.The results showed that the novel substrate has perfect stability and reproducibility with the detection limit of the n M level,and can solve the problem of Ag NPs reunion that can realize the rapid,sensitive,on-line,real-time,on-site or in situ analysis of antibiotics in environment and offer a new method for the emergency detection of sudden antibiotic pollution incident.3.Highly selective and sensitive surface enhanced Raman scattering nanosensors for detection of hydrogen peroxide in living cellsDetermination of hydrogen peroxide?H2O2?with high sensitivity and selectivity in living cells is a challenge for evaluating the diverse roles of H2O2 in the physiological and pathological processes.In this work,we present novel surface enhanced Raman scattering?SERS?nanosensors,4-carboxyphenylboronic acid?4-CA?modified gold nanoparticles?Au NPs/4-CA?,for sensing H2O2 in living cells.The nanosensors are based on that the H2O2-triggered oxidation reaction with the arylboronate on Au NPs would liberate the phenol,thus causing changes of the SERS spectra of the nanosensors.The results show the nanosensors feature higher selectivity for H2O2 over other reactive oxygen species,abundant competing cellular thiols and biologically relevant species,as well as excellent sensitivity with a low detection limit of 80 n M,which fulfills the requirements for detection of H2O2 in a biological system.In addition,the SERS nanosensors exhibit long term stability against time and p H,and high biocompatibility.More importantly,the presented nanosensors can be successfully used for monitoring changes of H2O2 levels within living biological samples upon oxidative stress,which opens up new opportunities to study its cellular biochemistry.
Keywords/Search Tags:Micro/nano-Structures, Functional Materials, Single-Molecule Fluorescence Spectroscopy, Surface-enhanced Raman Scattering(SERS), Environmental Detection, Biological Analysis
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