| Electrochemiluminescence(ECL) is a process whereby species electrochemically generated at the electrode surface undergo electron-transfer reactions to form excited states that emit light. ECL technique is superior to fluorescent one in higher sensitivity and signal-to-noise ratio(S/N) due to the absence of background from unselective photoexcitation. In this thesis, developing an based on dual-stabilizers-capped Cd Se quantum dots(Cd Se QDs) ECL technology, and combining with nano materials, metal-organic framework materials and chemical biology biological method to build a well analysis and sensor system. Details are listed below:1. Sensitive and selective determining ascorbic acid and activity of alkaline phosphatase with eye-visible monochromatic electrochemiluminescence of dual-stabilizers-capped Cd Se quantum dots in carbon nanotube-Nafion compositeSensitive and selective determining bio-related molecule and enzyme play an important role in designing novel procedure for biological sensing and clinical diagnosis. Herein, we found that dual-stabilizers-capped Cd Se quantum dots(QDs) in composite film of multi-walled carbon nanotubes(CNTs) and Nafion, displaying eye-visible monochromatic electrochemiluminescence(ECL) with fwhm of 37 nm, offers promising ECL signal for detecting ascorbic acid(AA) as well as the activity of alkaline phosphatase(ALP) in biological samples. It was also shown that the dual-stabilizers-capped Cd Se can preserve their highly passivated surface states with prolonged lifetime of excited states in Nafion mixtures, and facilitate electron-transfer ability of Nafion film along with CNTs. Compared with the QDs/GCE, the ECL intensity is enhanced 1.8 times and triggering potential shifted to lower energy by 0.12 V on the Cd Se-CNTs-Nafion/GCE. The ECL quenching degree increases with increasing concentration of AA in the range of 0.01-30 nmol/L with a limit of detection(LOD) of 5 pmol/L. The activity of ALP was determined indirectly according to the concentration of AA, generated in the hydrolysis reaction of L-ascorbic acid 2-phosphate sesquimagnesium(AA-P) in the presence of ALP as a catalyst, with LOD of 1 mU/L. The proposed strategy is favorable for developing simple ECL sensor or device with high sensitivity, spectral resolution and less electrochemical interference.2. Based on dual-stabilizers-capped Cd Se quantum dots/metal-organic frameworks composites electrochemiluminescence and its biosensorNovel highly electrochemiluminescence metal-organic frameworks(MOFs) have been synthesized by encapsulating the dual-stabilizers-capped Cd Se dots(Cd Se QDs) with a high ECL intensity into the zeolitic imidazolate framework materials(ZIF-8). The synthesized functionalized QDs-MOFs not only maintain an excellent ECL intensity but also can strongly and selectively accumulate target analytes because of the adsorption property and unique structure of ZIF-8. Herein, because the Cd Se QDs preserved a stabilized ECL intensity with CNTs and the selective accumulation effect of MOFs, we found that the QDs-ZIF-8 composite in composite film of multi-walled carbon nanotubes can increased the ECL intensity and display a ECL analytical method for selective detecting H2O2 or O2?- in PBS environment. The research shown that the proposed ECL strategy displayed monochromatic ECL with fwhm of 37 nm and good application prospect. On the other side, the ECL enhanced intensity increases linearly with liner concentration of H2O2, the linear range were 0.1-200 ?mol/L, and corresponding limit of detection were 0.02 ?mol/L. In addition, we also got the lower concentration of O2?- is 0.3 ?mol/L. |
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