Electrogenerated Chemiluminescence Properties And Applications Of Pyridine Sulfonic Acid Complexes And Niacinamide Complexes

Electrogenerated Chemiluminescence?ECL?analytical technique have been widely used for bioanalysis,immunoassay,clinical diagnosis,etc.It has been a powerful analytical method because it retains the advantages of chemiluminescence?CL?but also has unique advantages of ECL such as high sensitivity,ease of operation,controllability of potential and so on.In early years,most researchers paid attention to the Ru?bpy?₃²⁺,which is the representative of the metal complexes,however,it is expensive.It would be important to develop novel ECL reagents and study their applications.According to the excellent ECL performance of terbium compounds,several terbium compounds were synthesized with ligands of pyridine sulfonic acids and pyridine amide.At the same time,we selected phthalic acids as second ligands and studied the ECL properties of ternary complexes.The paper is divided into following three parts:1.Tb?2-ps?₂·nH₂O and Tb?3-ps?₂·nH₂O were synthesized with ligands of pyridine-3-sulfonic acid,pyridine-2-sulfonic acid by a simple method according to literatures.They were characterized by FT-IR,energy-dispersive X-ray spectroscopy?EDX?,etc.Then an excellent ECL signal was observed with K₂S₂O₈ as the coreactant in NaAc-HAc buffer solution at-1.4V.Besides,the possible ECL reaction mechanism was proposed according to fluorescence spectra and ECL spectra.Under optimum conditions,an ECL sensor was constructed based on the effective quenching of ECL signal after addition of Cd²⁺.The liner range of Cd²⁺ was from 2.0×10-10 to 3.8×10-5 M with a low detection limit of 0.13 n M.2.Tb?Nica?₂·n?H₂O?was synthesized by coordinating with Tb with the ligand of niacinamide?Nica?.The complex was characterized by FT-IR,energy-dispersive X-ray spectroscopy?EDX?and its ECL behavior was studied in borax buffer solution with K₂S₂O₈ as coreactant.Then an excellent ECL signal was observed at-1.4V.Under optimum conditions,after addition of 5-methylphrazine-2-carboxylic acid?MPCA?into system,the ECLintensity decreased.Thus,a new ECL method was proposed for detection of MPCA.The liner range was from 2.0×10-10 to 2.0×10-4 M with a low detection limit of 1.67 n M.3.Based on the study of Tb?3-ps?₂·n H₂O,we synthesized Tb?3-ps?₂?PA??H₂O?₂?Tb?3-ps?₂?IPA??H₂O?₂?Tb?3-ps?₂?PTA??H₂O?₂ with the second ligands of phthalic acid?PA?,isophthalic acid?IPA?,terephthalic acid?PTA?.The ECL properties of these compounds have been studied.The ECL performance was improved greatly,because the phthalic acids compete with water molecules during the coordination with metal.As for the difference of ECL performance and water solubility,which was related to the location of the phthalate carboxyl group.Relatively,Tb?3-ps?₂?PA??H₂O?₂ and Tb?3-ps?₂?IPA??H₂O?₂ presented more excellent ECL performance in aqueous solution.