【作者】 崔红蕾；

【导师】 苏星光；

【作者基本信息】 吉林大学 ， 分析化学， 2010， 硕士

【摘要】 本论文中,我们首先制备了CdTe量子点/聚电解质多层膜,然后利用CdTe量子点/聚电解质多层膜的荧光特性,开拓了其在有机气态小分子与有机磷农药检测领域的应用。论文主要包括三部分内容:论文第一章综述了量子点的结构、光学特性,制备方法,介绍了量子点在各个研究领域中的应用现状。论文第二章中,我们利用层层自组装法制备CdTe量子点/聚电解质多层膜,并对其进行结构表征和光学特性的检测。甲醛对CdTe荧光量子点/聚电解质多层膜的荧光有猝灭作用。在优化了反应时间、猝灭温度等反应条件后,对气态甲醛进行了检测,检测甲醛的线性范围为5-500ppb,检出限为1ppb。论文第三章中,我们将CdTe荧光量子点/聚电解质多层膜用于农药中有机磷的检测。以对氧磷为测定组分,由于其含有的磷氧双键对CdTe量子点的荧光有增强作用,根据CdTe荧光量子点/聚电解质多层膜荧光强度的变化可以检测对氧磷的浓度。更多还原

【Abstract】 Semiconductor quantum dots (QDs) have drawn widespread attention and exploited in a variety of multicolor imaging for bio-sample, vivo tissue and bio-fluorescence probe, especially in fluorescence sensors in the past decade. In the synthesis approaches of quantum dots, the aqueous syntheses are easier controlled, higher repeated, lower cost. It is easily to modify the surface of QDs with different functional groups using the aqueous syntheses. QDs provide robust and stable signal intensity, narrow emission spectra, and the broad emission wavelength which can be turned continuously by changing the size and component of the QD particles.In this work, CdTe quantum dots (QDs)/polyelectrolyte multilayer films (QDMF) were assembled by layer-by-layer (LBL) deposition of oppositely charged CdTe QDs and poly(dimethyldiallylemmonium chloride) (PDDA). Based on the fluorescence quenching of CdTe quantum dots (QDs)/polyelectrolyte multilayer films, a novel method for the direct detection of gaseous formaldehyde (QDMF) was proposed in this paper. Formaldehyde can quench the fluorescence of CdTe QDs multilayer films effectively. Under the optimization conditions, the fluorescence intensity of QDs decreased linearly with the increase of formaldehyde concentration in the range of 5–500 ppb. The detection limit for formaldehyde was 1 ppb. The quenching mechanism of CdTe QDs multilayer films by formaldehyde was also studied in detail. This proposed approach was simple, rapid and had excellent selectivity and sensitivity for the detection of gaseous formaldehydeCdTe quantum dots (QDs)/polyelectrolyte multilayer films were also used as sensors for paraoxon detection. Paraoxon can enhance the fluorescence intensity of CdTe QDs multilayer films effectively. Enhancements of photoluminescence of QDs is most likely due to the passivation of surface traps by ligand groups (P=O group of paraoxon). Under the optimization conditions, the fluorescence intensity of QDs multilayer films increased linearly with the increase of paraoxon concentration in the range of 5-200 ppb. The detection limit for paraoxon was 2 ppb. This approach was simple, rapid and had excellent selectivity and sensitivity for the detection of organophosphates.更多还原