| Electrochemiluminescence (ECL) is the combination of chemiluminescence(CL) method and electrochemical method. ECL method not only possesses the advantages of wide linear range and high sensitivity belonging to CL, but also has some advantages that is not showed in CL method. ECL reactions are easy to be controlled. The intermediates of ECL reactions are generated at the electrode surface, so the occurrence of ECL reactions can been controlled by adjusting the size of potential or current imposed on the electrod. This is a beneficial factor to improve the selectivity of ECL. When several kinds of ion existe in the system, separation and enrichment can been realized via imposing different voltage. The apparatus used in ECL method are simple, and the automation of ECL method can been realized easily.This thesis contains two parts. The first part is a review of literature, which reports the general development of the ECL mothod,the basic reaction mechanism of ECL and the kinds of ECL. The second part is research report. Ciprofloxacin,tetracycline and adriamycin were chose as research subject. The new ECL systems of ciprofloxacin,tetracycline and adriamycin/K2S2O8 were established based on the enhancement on the weak luminescence of S2O82-, and the mechanisms were discussed in detail.1 Investigation of potassium persulfate/ciprofloxacin electrochemiluminescence systemand its applicationThe electrochemiluminescence(ECL) of potassium persulfate (K2S2O8)/ ciprofloxacin(CPF) system was investigated. The sulfate radical anion(SO4-·) was generated from the electrochemical reduction of persulfate. The excited double oxygen[1(O2)2] was produced by a series reaction of SO4-· and water. There was a weak luminescence when [1(O2)2] transform to triplet oxygen(3O2). The energy from 1(O2)2 was transferred to CPF when CPF was present, and CPF changed into excited state CPF(CPF*). CPF* returned to the ground state accompanying a strong luminescence. Based on the strong luminescence of K2S2O8/CPF ECL system, the new ECL method for the determination of CPF was proposed. Under the optimal conditions, including a BR buffer(pH 6.09) containing 1.5×10-3 mol/L K2S2O8 and application of 5mA direct current, the ECL intensity difference was linear with the concentration of ciprofloxacin in the range of 2.0×10-6- 8.0×10-5 mol/L with the detection limit of 3×10-7 mol/L(S/N=3). The RSD for the measurement of 1.0×10-5 mol/L ciprofloxacin (n = 11) was 1.8%.2 Investigation of potassium persulfate/tetracycline electrochemiluminescence system and its applicationThe electrochemiluminescence(ECL) of potassium persulfate (K2S2O8)/tetracycline (TC) system was investigated. The sulfate radical anion(SO4-·) was generated from the electrochemical reduction of persulfate. The excited double oxygen[1(O2)2] was produced by a series reaction of SO4-· and water. There was a weak luminescence when [1(O2)2] transform to triplet oxygen(3O2). The 10-hydroxy group of TC would oxided TC quinone by S2O82- when TC was present. The energy from 1(O2)2 was transferred to TC quinone, and TC quinone change into excited state TC quinone. The excited state TC quinone returned to the ground state accompanying a strong luminescence. Based on the strong luminescence of K2S2O8/TC ECL system, the new ECL method for the determination of TC was proposed. Under the optimal conditions, including a BR buffer(pH 10.38) containing 8.0×10-4 mol/L K2S2O8 and application of 10mA direct current, the ECL intensity difference was linear with the concentration of TC in the range of 1.0×10-6- 1.5×10-4 mol/L with the detection limit of 2×10-7 mol/L(S/N=3). The RSD for the measurement of 2.0×10-5 mol/L TC (n = 11) was 1. 1%.3 Cathodic electrochemiluminescence behavior of potassium persulfate/adriamycin systemThe electrochemiluminescence(ECL) of potassium persulfate (K2S2O8)/ adriamycin (ADM) system was investigated. The semiquinone radical that was generated from the electrochemical reduction of ADM was oxidized by persulfate. The semiquinone radical change into excited state ADM(ADM*). ADM* returned to the ground state accompanying a strong luminescence. Based on the strong luminescence of K2S2O8/ ADM ECL system, the new ECL method for the determination of ADM was proposed. Under the optimal conditions, containing 0.5 mol/L KNO3 plus 5.0×10-2 mol/L K2S2O8 and application of 15mA direct current, the ECL intensity difference was linear with the concentration of ADM in the range of 1.5×10-6- 2.0×10-4 mol/L with the detection limit of 3×10-7 mol/L(S/N=3). The RSD for the measurement of 1.0×10-4 mol/L ADM (n = 11) was 1.5%. |
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