| The major tasks of analytical chemistry are the determination of chemical compositions and concents,and characterization of chemical structrues of materials.Update,modern analytical and testing technology has play important roles in life science,medicine,materials science,environment science,food safety,and energy science.With the development of society and advances in science and technology,developing highly sensitive,selective and highly throughput analytical technologies for targets has became one of the major requirement of the society.As the most widely used analytical technology,luminescence sensing technology also need innovations to realize high throughput,high sensitivity and high selectivity in the process of applications of sensors.Therefore,the author of this dissertation is interested in developing novel luminescence imaging technology and new chemical sensors based on functional materials to improve the sensitivity,selectivity and throughput of luminescence sensing technology.As a new technology,electrochemiluminescence(ECL)imaging may solve the problem of low throughput of present luminescence sensors.Electrochemiluminescence(ECL)imaging is developed based on the combination of electrochemiluminescence(ECL)with imaging techniques.This technique has not only many advantages of electrochemiluminescence,such as low background signal,high sensitivity and wide linear response range,but also has many advantages of imaging techniques,such as visualization and high throughput.As new materials,functional metal-organic frameworks(MOFs)may solve those problems of low sensitivity and bad selectivity met in luminescence sensors.First,functional metal-organic frameworks(MOFs)maintain properties inheriting from MOFs,such as highly selective and efficient adsorption for some metal ions and small molecules,which may lead to the accumulation of target analytes to improve the sensitivity of the sensor.The second,the functionalized MOFs have unique properties of the doping agent,for example,the fluorescence properties of the doping agent and the sensing selectivity,which improves the selectivity of light sensing.In this dissertation,studies were focused on ECL imaging and functional metal-organic frameworks in luminescenc sensors.In Chapter 1,the general introduction and characteristics of ECL imaging,the mechanisms of ECL were briefly reviewed.Then some basic concepts related with MOFs,their synthesis,applications and recent advances in their studies were briefly summarized.Finally,the significance of this study and research purposes were mentioned.In Chapter 2,a novel electrochemiluminescence(ECL,a technology changing electric current into light)imaging-based screening platform for electrocatalysts used in fuel cells has been developed.The ECL imaging-based screening platform consists of bipolar electrode array-bridged EC/ECL twin cells,by which electrocatalytic reduction currents of O2 can be imaged directly by ECL.The ECL imaging-based screening platform is simple in instrumentation,can image the "current-voltage"dependence directly,reversibly,and sensitively,and may enable the activities of electrocatalysts to be evaluated in a high-throughput way.In Chapter 3,a novel electrochemiluminescence(ECL,a technology changing electric current into light)imaging used in studying the IR drop in the thin layer has been developed.The distribution of IR drop in the thin layer could be visually and intuitively observed by the novel ECL imaging method.The experimental results show that the distribution of IR drop in the thin layer is related to impedance and current.The formula for the distribution of IR drop in narrow thin layer is(IR)(n,j)=n(n+1)/2IR(nIR+(n-1)IR+…+IR);And the formula for the distribution of IR drop in wide thin layer is(IR)(n,j)=I·R(n,j),where R(n,j)is R(n,j)=?/T/In|1+sin?1/cos?1|·|cos?m/1+sin?m|.But when electrodes in the wide thin layer are dense,the IR drop distribution of wide thin layer is close to that of narrow thin layer.In Chapter 4,novel highly fluorescent(FL)metal-organic frameworks(MOFs)have been synthesized by encapsulating branched poly-(ethylenimine)-capped carbon quantum dots(BPEI-CQDs)with a high FL quantum yield into the zeolitic imidazolate framework materials(ZIF-8).The as-synthesized FL-functionalized MOFs not only maintain an excellent FL activity and sensing selectivity inheriting from BPEI-CQDs,but also can strongly and selectively accumulate target analytes due to the adsorption property of MOFs.The obtained BPEI-CQDs/ZIF-8 composites have been used to develop an ultrasensitive and highly selective sensor for Cu2+ ion,with a wide response range(2 to 1000 nM)and a very low detection limit(80 pM),and have been successfully applied in the detection of Cu2+ ions in environmental water samples.In Chapter 5,using Ru(bpy)32+ as dopants and bio-MOF-1 as frame,we prepare functional metal-organic frameworks(RuMOFs)with strong red fluorescence.The prepared Ru(bpy)32+-functionalized MOFs was characterized by UV,FL,IR,TGA,XRD,N2 absorption measurements and so on.The experimental results suggest that the as-synthesized Ru(bpy)32+-functionalized MOFs not only maintain an excellent ECL activity and fluorescent activity inheriting from Ru(bpy)32+,but also can strongly and selectively accumulate target analytes due to the adsorption property of MOFs.In Chapter 6,RuMOFs was applied for the detection of Hg2+ ion in water.This detection was based on the phenomenon that Hg2+ ion could induce the ruthenium of RuMOFs to release,bio-MOF-1 could adsorb mercury ions sensitively and optical properties of Ru(bpy)32+.A new,simple,fast and sensitive method for determination of the mercury ions in water samples was established by optimizing the experimental conditions.Moreover,the detecting mechanism was also studied in detail.The linear response range was from 1 to 8 pM,and detection limit(S/N = 3)was 0.053 pM.The detection result for mercury ions in Min River by the proposed method is consistent with that by ICP-MS,indicating that the detection method is accurate and practical. |
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