Luminol Research And Analytical Applications Of The New Features

Two part, review and research report, are included, in this thesis, theprogress in Electrochemiluminescent assay is reviewed. This review begins with thefundamental researches in ECL, including the development, mechanism, apparatus ofECL method and the application of ECL in analytic chemistry with many years'references in detail. Final1y, the main prob1ems in the further investigation are outlooked,so are its prospects. The research report is mainly concentrated on the stody of a highlysensitive luminol ECL methods for determination of tetracycline, Epinephrine, isoniazidand captopril etc. The mechanism of this ECL systcm is also discussed.Electrochemi1uminescence method is one of the most interesting subjects inanalytica1 chemitry fie1d. It was first observed by Harvey in l929, but only during thel980s, it was paid much attention by the analysts and developed to be a useful new toolfor the determination of a variety of analytes. ECL is a technique by which achemiluminescence's reaction is produced in the vicinity of an e1ectrode by active speciesgenerated electrochemically. The ECL technique not only retains the advantage of theconventional electroanalysis, such as the smaller sample volume requiremcnt and thebetter selectivity by selecting a special electrolytic potential, but also allows CL methodsto be simplified using flow system with reduce numbers of reagents, since active reagentscan be produced electrochemically from passive precursors in the sample or carrierstream. In addition it is often possible to regenerate reagents, and occasionally analytes,allowing the ECL signal to be sustained for longer than conventional CL, and eachmolecule can emit several photons per measurement cycle, which enhance thc sensitivity' of the technique greatly This approach has many distinct advantages over other methods,and it has been applied successfully to many fields, such as life science, clinical medicine,environment, immunoassays and DNA probe ana1ysis etc. Nowadays, analysts areworking over biological chip, perfecting ECL immunoassay and exploiting ECLsubstance etC.The more sensitive and selective fiowinjection ECL methods for some specialfunction groups compound, such as, hydroxybenzene compounds, amides, tetfacyclineand thiol group compounds was develoPed, resPeCtively The main principle was thatthese compounds could gwtly enhance the weak ECL signal arising from theelectrOChemical oxidation of lumino1 in weak alkaline medium. Based on theseobserVations and the choices of the relating exPerimental conditions, the relative ECLintgnsity was linear with totrCycline concentration in the range of 2.0xl0-8 g/ml--8.0x10' g/ml and with a detecting limit of 6.0 xl0-9 g/ml, The linear range ofchlorotetracycline was from 4 X l0-'g/ml to 2 X 10-Whl and with l .2x l0-7 g/ml detectinglimit, The linear range of oxytetracyc1ine was from 2 X l0'g/ml to 8 X l0'thel and witha deteCing limit of 6x10y g/ml; The range of determination for EP was5.0xl0-'moltu.6.106..l1, the detoChng lidrit of this method was 2.8 X 10-8 moim,The ECL intrisity response to phloroglucinol increase linearly with concentr8tion from4.0xl0-'g/ml to 4.0xl0"g/ml and a deteCting limit of l .2 X l07 g/ml can be achieved,The relationship betwee ECL intollsity and the concentraion of isoniazid was linear inthe range of 7.0x10'mol1 -- 6.0xl0'mol1, the dtation limit has been estimated as3.4 X l0-s moim; The linear range of hydrazine is from 3.0.l0"molth to 4.0xl0-'mol1and with a derecting limit of l.1x10"molth: The linear fange of determination fOrCaPtOpril was from 7.0xl0-8 mol/L to 6.0.l06 moim and with a detecting limit of 3.4'l0-s molth. The linea range of sulphide ion is from 5.0 X l0-'mol1 tO 4.0 X l0-'molthand with a detecting limit of l .8 X l0-vmolth, The linear range of cysteine is from 1 Xl0:g/ml to 6 X 1'0-'g/mL and with a deteCting limit of 6.0 X l 0-'g/mL.