Study On Copper Clusters Chemiluminescence New Systems And Its Applications

Chemiluminescent materials and chemiluminescence（CL）systems are the prerequisite and basis for the application of CL.Metal nanoclusters are composed of several to tens of atoms and have drawn considerable research interest due to their unique electrical,physical and optical properties.The precursor for the preparation of copper clusters（CuNCs）is relatively abundant,inexpensive,readily available from commercial sources and friendly environmental.Therefore,CuNCs are more favorable for various applications.The transition metal in highest oxidation state such as silver complex（DPA）and copper complex（DPC）has strong oxidizing ability owing to electron deficiency in the second layer d orbital and the outermost orbitals.They are all strong oxidant with higher stability under the appropriate condition,DPA and DPC have been widely used for the study of inorganic,organic reaction kinetics and oxidation mechanisms.Unfortunately,there are few research and application of DPA and DPC in CL analysis.Therefore,it is of great significance to study the new CL system and application of CuNCs,DPA and DPC.The main content of paper is as follows:1.Green-emitting CuNCs were prepared through single-step reduction of copper dichloride by cysteine in alkaline medium.The surface morphology and optical properties of CuNCs were characterized by means of transmission electron microscopy,fourier transform infrared spectrometer,fluorescence spectrometer and UV-vis spectrophotometer.2.The CL new systems of Ce（IV）/KMnO₄-CuNCs,DPA-FA-CuNCs and DPC-FA/IAA were established under acidic condition.3.It was found that the CuNCs could be oxidized by Ce（IV）or KMnO₄ in acidic medium and exhibited a weak CL,which was remarkably enhanced by THP.but the enhanced CL intensity of Ce（IV）-CuNCs system by THP was greater than that of KMnO₄-CuNCs system.Therefore,Ce（IV）-CuNCs CL system was applied to the detect THP.It was observed that DPA could oxidize FA to generate weak CL,after the addition of CuNCs,the CL intensity was dramatically enhanced,interestingly,the CL intensity of DPA-FA system containing CuNCs could be quenched by NO₂^–,based on these phenomena,a chemluminescent probe for detection of FA and NO₂^–was explored.The new CL reaction was based on the direct oxidation of FA or IAA by DPC in an acidic medium,furthermore,CL signals of reaction IAA and DPC were greater than that of reaction FA and DPC,however,after the addition of S^2-,the DPC-FA CL system was more greater to it,thus,DPC-FA CL system was used to detect S^2-.4.The Ce（IV）-CuNCs CL system was applied to pharmaceutical formulations and human plasma samples,and the recovery was in the range of 94.7%–104.0%.The DPA-FA-CuNCs CL system was applied to detect FA in commercial pharmaceutical tablets and urine sample with recoveries of 97.3%–105.0%and detect NO₂^–in tap water,spring water,pickled vegetable and sausage with recoveries of 91.9%–105.0%.The DPC-FA CL system was successfully applied to the direct determination of S^2-in rain water,river water and tap water,and the recovery was in the range of 90.0%–110%.Beside,the possible CL reaction mechanism was elucidated by means of CL spectra,UV-vis spectra and some radical scavenger experiments.The mechanism study showed that the emitter was excited state Mn（II）in the KMnO₄-CuNCs system,while excited state CuNCs acted as emitting species in the Ce（IV）-CuNCs system.The possible emitting species of both DPA-FA-CuNCs CL system and DPC-FA CL system were PCA*and（O₂）₂*.