The Synthesis Of Novel Cu-MOFs Functionalized Nanomaterials And Their Applications For The Determination Of Some Small Biomolecules By Flow Injection-chemiluminescence

Metal-organic frameworks(MOFs)are nanomaterials with periodic network structure.Owing to the large specific surface area,diverse structure and unique nature,MOFs are hot topics in novel functional materials,and thus many potential applications have been proposed in the domains of small organic molecules adsorption and separation,sensing,catalysis and so on.It is important that MOFs are used as catalysts for chemiluminescence(CL)due to the unique structure and performance.Flow injection-chemiluminescence(FI-CL)has advantages of simple equipment,high sensitivity,low consumption of reagents and samples,short analysis time,as well as good reproducibility,which has been widely used in many fields such as pharmaceutical detection,food analysis,and clinical examination.However,most of the CL systems have disadvantages of low luminous efficiency and weak luminescence intensity,which restricted the application of CL in micro or trace component assay.Currently,it is one of the important research areas to explore new catalysts,which can effectively improve the detection sensitivity of CL.Combining MOFs and other materials as novel CL catalysts is important for improving the sensitivity and broadening the application because MOFs composites possess high catalytic activity and good water-solubility.In this thesis,a series of Cu-MOFs(HKUST-1)complex as novel CL catalysts were synthesized based on characteristics of MOFs such as porous structure and easy surface modification.Luminol-hydrogen peroxide system was used as a model to study the CL catalytic behavior of the prepared catalysts.Based on the excellent catalytic activity of the HKUST-1 composites,the new FI-CL methods for the determination of dopamine,ascorbic acid,uric acid and GSH were established.These work not only enriched the types of CL catalysts,but also broadened the application of MOFs in chemical catalysis,and also promoted the application of FI-CL in the rapid and sensitive detection of micro or trace amount of small biological molecules.This thesis is divided into following parts:1.A sensitive biosensor for dopamine determination based on the unique catalytic chemiluminescence of metal–organic framework HKUST-1Due to the porous structure and large specific surface area,HKUST-1 as a catalyst can significantly improve the luminous efficiency of CL reaction.Based on this consideration,in this chapter,we took advantage of the excellent catalytic activity of HK UST-1 for luminol-H₂O₂ system and dopamine(DA)inhibiting the luminol-H₂O₂-HKUST-1 system,a new FI-CL method for the determination of DA was established.HKUST-1 was used in the CL system for the first time and the catalytic activity of HKUST-1 for luminol-H₂O₂ system was studied in an alkaline medium.Compared with the luminol-H₂O₂system,the CL intensity of luminol-H₂O₂-HKUST-1 system was enhanced significantly up to about 90-fold.Under the optimized conditions,the linear range of the present method for DA was in the range of 0.010-0.70?M with the detection limit of 2.3 n M(3S/N).The proposed method was applied to the determination of DA in human plasma and urine samples,and the recoveries were 90.0-102.0%,78.7-110.6%,respectively.The relative standard deviations were 1.0-3.5%,0.8-4.3%,respectively.2.Chemiluminescence determination of ascorbic acid using graphene oxide@copper-based metal–organic frameworks as a catalystIn this chapter,based on the stability and water-soluble of graphene oxide(GO),a series of different proportions of GO@MOFs(HK UST-1)were prepared by solvothermal method,and the effect of the different ratio between GO and HKUST-1on the CL property was investigated.The result suggested that the outstanding catalytic CL performance of GO@HKUST-1 were attributed to two aspects:the synergistic effect between GO and HKUST-1 and facilitating the decomposition of H₂O₂ to generate more hydroxyl radical due to the porous structure of GO@HKUST-1.Based on the phenomenon that ascorbic acid(AA)could consume H₂O₂and resulted in the decrease of CL intensity,a new FI-CL method for the determination of AA was developed.Under the optimized conditions,a good linear relationship was obtained from 0.0010 to 10?M,and the detection limit was 0.35 n M.Additionally,a sampling frequency of 168 per hour was achieved.The proposed method has been applied to detect AA in commercial food and fruit juices with the recovery of 88.0%-103.0%.3.Chemiluminescence determination of uric acid using Mo S₂@MOFs as a catalystIn this chapter,Mo S₂@MOFs(HKUST-1)nanocomposites were synthesized by solvothermal method for the first time,and the feasibility of determination of uric acid(UA)by FI-CL was investigated.Experimental results showed that Mo S₂@HKUST-1can significantly improve the CL signal of luminol-H₂O₂ system because of the synergistic effect between Mo S₂ and HKUST-1.When UA presented,the CL intensity of luminol-H₂O₂-Mo S₂@HKUST-1 system were reduced sharply.Based on this phenomenon,a FI-CL method for the determination of UA has been developed.Under the optimized conditions,a good linear relationship was obtained from 0.075 to 1.0?M,and the detection limit was 0.90 n M.The present method displayed high sensitivity,excellent stability and good repeatability,which has been applied to detect UA in human serum sample with the recovery of 90.9-101.6%.4.Luminol and Pt NPs dual-functionalized MOFs hybrids with high chemiluminescence for detection of glutathione in cellsIn this chapter,luminol-Pt NPs@HK UST-1 hybrids were first synthesized,which were self-reinforced nanocomposite luminescent material with luminol and Pt NPs on the surface of HKUST-1.During this process,luminol was luminescent reagent,reducing agent and stabilizer.Because of their special compositions,the as-prepared luminol-Pt NPs@HKUST-1 hybrids not only exhibited the excellent CL behavior,but also had good performance of cataluminescence.With these features,a new sensitive FI-CL system was constructed using hydrogen peroxide as a co-reactant.On the basis of glutathione(GSH)inhibiting the luminol-Pt NPs@HKUST-1-H₂O₂ system,a FI-CL method for the determination of GSH was achieved.Under the optimized conditions,the linear range of this method was 0.0010-10?M with the detection limit of 0.66 nm,and this method was successfully applied for the determination of GSH in cells with satisfactory results.This work not only supplied a new approach for preparation of CL catalyst,but also widened the application scope of MOFs.