基于Mn掺杂ZnS量子点温室磷光检测左氧氟沙星

以3-巯基丙酸为稳定剂,采用水相合成法制备Mn掺杂Zn S量子点,由于左氧氟沙星(LVFX)的3-羰基与Mn掺杂Zn S量子点表面的二价金属离子形成配合物,使得Mn掺杂Zn S量子点发生温室磷光猝灭效应,从而构建了一种快速、灵敏检测人体体液中LVFX的新方法。在最佳条件下(p H 7.4,反应时间10 min),其线性关系△RTP=27.56c(LVFX)+52.002(R=0.995),线性范围0.5~100μmol/L,检出限0.35μmol/L,加标回收率96.2%~104.6%,可用于LVFX注射液与人体尿液中LVFX的快速测定。     

基于MPA包覆的Mn掺杂ZnS量子点室温磷光法检测甲硝唑

以3-巯基丙酸(MPA)包覆的Mn掺杂Zn S量子点作为室温磷光探针,基于甲硝唑对Mn掺杂Zn S量子点磷光猝灭效应,建立了一种简单、快速测定甲硝唑含量的磷光检测方法。在最佳实验条件下,所建立的方法检测范围为1.16²32μmol/L,检出限为0.09μmol/L,可用于实际药品中甲硝唑的快速标定。     

基于MPA包覆的Mn掺杂ZnS量子点室温磷光法检测甲硝唑

以3-巯基丙酸(MPA)包覆的Mn掺杂Zn S量子点作为室温磷光探针,基于甲硝唑对Mn掺杂Zn S量子点磷光猝灭效应,建立了一种简单、快速测定甲硝唑含量的磷光检测方法。在最佳实验条件下,所建立的方法检测范围为1.16~232μmol/L,检出限为0.09μmol/L,可用于实际药品中甲硝唑的快速标定。     

基于Mn掺杂ZnS量子点室温磷光检测头孢克肟

在室温下,利用巯基丙酸(MPA)包裹Mn掺杂ZnS量子点的磷光信号,建立一种检测头孢克肟(CEF)的新方法。在最佳条件下(0.4 mg/L量子点溶液和pH=7.4磷酸缓冲液),CEF的加入使MPA包裹的Mn掺杂ZnS量子点的室温磷光发生猝灭,磷光强度(ΔRTP)与CEF呈现良好的线性关系,其线性范围1.2~24μmol/L,最低检出限0.49μmol/L,相关系数0.993,实际样品的检测回收率为93.7%~101.3%。该方法简便快速、成本低、选择性好等,能够用于人体液中CEF含量的分析。     

基于Mn掺杂ZnS量子点室温磷光检测头孢克肟

在室温下,利用巯基丙酸(MPA)包裹Mn掺杂ZnS量子点的磷光信号,建立一种检测头孢克肟(CEF)的新方法。在最佳条件下(0.4 mg/L量子点溶液和pH=7.4磷酸缓冲液),CEF的加入使MPA包裹的Mn掺杂ZnS量子点的室温磷光发生猝灭,磷光强度(ΔRTP)与CEF呈现良好的线性关系,其线性范围1.2²4μmol/L,最低检出限0.49μmol/L,相关系数0.993,实际样品的检测回收率为93.7%24μmol/L,最低检出限0.49μmol/L,相关系数0.993,实际样品的检测回收率为93.7%¹01.3%。该方法简便快速、成本低、选择性好等,能够用于人体液中CEF含量的分析。     

基于Mn掺杂ZnS室温磷光量子点检测盐酸洛美沙星方法的研究

利用水相合成法制备了三巯基丙酸包裹的Mn掺杂ZnS量子点(MPA-Mn/ZnSQDs),基于该量子点的室温磷光性质,构建了一种定量检测盐酸洛美沙星(LFLX)的新方法。在最优实验条件下(pH7.4,反应时间10min),LFLX浓度在0.002~1.4μg/mL范围内与MPA-Mn/ZnSQDs的磷光猝灭强度呈良好的线性关系(r=0.993),方法检出限为0.7×10-3μg/mL。该方法相对无共存物质的干扰,并适用于LFLX眼药水及人体尿样中LFLX的快速检测。     

基于Mn掺杂ZnS量子点的室温磷光检测吡柔比星

以3-巯基丙酸(MPA)为稳定剂采用水相合成法合成Mn掺杂Zn S量子点,基于MPA包裹的Mn掺杂Zn S量子点的室温磷光性质,建立了一种高效、灵敏的检测蒽醌类抗癌药物吡柔比星(Pirarubicin,THP)的新方法。在p H=7.4的磷酸盐缓冲溶液中,THP通过光诱导电子转移可以猝灭Mn掺杂Zn S QDs在波长590 nm处的磷光,且在一定范围内THP的浓度与磷光猝灭强度呈正比例关系,线性范围为0.3~16.2μg/m L,相关系数为0.992,方法检出限为0.072μg/m L。     

Mn掺杂ZnS量子点荧光猝灭法测定双酚A

本文采用水热法分别制备了Mn2+掺杂ZnS量子点和聚苯乙烯-甲基丙烯酸聚合物,超声辅助包裹法制备双酚A印迹型量子点纳米微球复合物。通过量子点荧光猝灭效应对双酚A进行定量分析。本实验考察了量子点共聚物与双酚A在不同pH值的缓冲溶液中作用及不同反应时间对量子点荧光猝灭效率的影响。实验结果表明,在pH10.5的碱性介质及反应时间30min条件下,方法的线性范围为60～820 ng.mL-1,检出限为0.02μg.mL-1。该方法用于环境水样中双酚A的测定,结果满意。     

硫化锌掺锰量子点磷光探针法快速检测牛奶中的三聚氰胺

基于三聚氰胺(MA)对谷胱甘肽(还原型)包覆的硫化锌掺锰量子点磷光的猝灭作用,建立了快速测定牛奶中MA的磷光探针法。实验结果表明,在中性溶液中,MA浓度在8.0~70.0 nmol/L范围内,磷光量子点强度的猝灭值(ΔPL)与MA的浓度呈线性关系,线性方程为ΔPL=1.59cMA+15.17,相关系数(r)为0.996 5,方法检出限4.0nmol/L。将本方法用于牛奶加标样品中MA的分析,RSD为3.26%,MA的平均回收率为90.05%~98.08%。     

基于Mn掺杂ZnS量子点的室温磷光法检测顺铂

以3-巯基丙酸(MPA)为稳定剂,利用水相合成法合成具有独特光学性质的Mn掺杂Zn S量子点(QDs),基于该量子点的室温磷光性质建立了一种高效、灵敏的检测抗癌药物顺铂(cisplatin,DDP)的新方法。该量子点在室温不除氧的条件下即可发射较强的磷光信号。在p H=7.4的磷酸盐缓冲液中,顺铂作为良好的电子受体,能够通过光诱导电子转移(PIET)原理猝灭Mn掺杂Zn S量子点的室温磷光(RTP)。在最优实验条件下,该方法的线性范围为2.5~50μmol/L,相关系数R=0.99,检出限为0.85μmol/L。     

Direct electrochemiluminescence of CdTe quantum dots based on room temperature ionic liquid film and high sensitivity sensing of gossypol

A new method with high sensitivity was developed to determine gossypol content using CdTe quantum dot (QD) electrochemiluminescence (ECL) with a room temperature ionic liquid (RTIL) modified glassy carbon (GC) electrode. It was found that use of RTIL film on the GC electrode can greatly enhance the ECL intensity of CdTe QDs, and the ECL peak potential and ECL onset potential were both shifted positively. Under optimal conditions, the quenching effect of gossypol on the ECL emission of CdTe QDs was observed, and ECL intensity showed a good linear relationship in the gossypol concentration range of 5.0 × 10⁻⁷ to 5.0 × 10⁻⁹ M with a detection limit of 5.0 × 10⁻⁹ M. The proposed method was used to detect gossypol in cottonseed oil with satisfactory results. As a result, the introduction of an RTIL-modified electrode can extend the analytical applications of QD ECL systems.     

基于氮掺杂碳量子点的荧光微球制备和Fe3+检测

分别以尿素、氨水、二乙烯三胺、多乙烯多胺为氮源,绿色廉价的白菜为碳源,采用水热法合成氮掺杂的蓝色荧光碳量子点,结果表明多乙烯多胺氮掺杂碳量子点（NCDs）荧光量子产率最高为53.3%。然后将NCDs作为荧光探针应用于荧光微球制备和Fe³⁺检测方面,以三聚氰胺甲醛（MF）为载体,合成了氨基化MF荧光微球;基于Fe³⁺对NCDs良好的荧光猝灭效应,建立了一种荧光测定Fe³⁺的方法,并对NCDs和MF荧光微球的结构和性能进行表征。结果表明,NCDs的荧光性能得到了显著的改善;MF荧光微球单分散性好、荧光性能好且稳定,在生物医学领域方面有重要的应用价值;NCDs对Fe³⁺具有单一选择性,Fe³⁺浓度在0~2μmol/L内与NCDs的荧光猝灭程度呈良好的线性关系（R²=0.9945）,检出限为0.035μmol/L。将该体系应用于实际水样中Fe³⁺的测定,相对标准偏差（RSD,n=6）在1.42%~3.02%内,加标回收率在98.7%~104.5%之间。该体系对Fe³⁺检测灵敏性好、选择性高以及抗干扰性强,在离子分析检测方面有潜在的应用前景。     

Structure and luminescence of Eu doped glass ceramics embedding ZnO quantum dots

Eu³⁺ doped glass ceramics embedding ZnO quantum dots (QDs) were successfully prepared by a sol–gel method. High-resolution transmission electron microscopy (HRTEM) observations revealed that ZnO QDs with size of 3–6 nm precipitated homogeneously among the SiO₂ glassy matrix after thermal treatment of the precursor sample. Such glass ceramics show a high transparency in the visible-infrared range due to the much smaller size of the ZnO QDs than the wavelength of the visible light. The emission and excitation spectra of the samples with various ZnO contents were studied. Based on Judd–Ofelt theory, the intensity parameter Ω₂ was evaluated to investigate the change of the environment around Eu³⁺ in samples with and without QDs.     

Synthesis and characterisation of functional manganese doped ZnS quantum dots for bio-imaging application

Fluorescent quantum dots (QDs) are potential candidates for bio-imaging but major problems in using them for bio-imaging applications are either bandgap lying in UV region or the cytotoxicity of the visible light-excited cadmium-based QDs. Keeping these things in mind, glutathione (GLT) functionalised Mn-doped ZnS QDs has been studied to make a desired fluorescent system for bioimaging application. XRD measurements show that grain size decreases at higher concentration of GLT capping on Mn-doped quantum dots. UV–visible studies show that the band gap shows a blue shift at higher GLT concentration. FTIR studies confirm GLT functionalisation on the surface of ZnS QDs. Both UV excited and IR excited photoluminescence spectrum of samples exhibited a tunable orange emission intensity with increase in GLT concentration however multiphoton infrared excited spectra was used to show the feasibility of GLT functionalised ZnS:Mn quantum dots for a real application in a biological window of 650–950?nm.     

Structure and magnetism in the Zn–Mn–O system: A candidate for room temperature ferromagnetic semiconductor

The reactivity of the Zn–Mn–O system, prepared by conventional ceramic routes using ZnO and MnO₂ as starting materials are described and correlated with the magnetic response. X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy techniques have been used for the structural analysis. The ferromagnetic response is unambiguously determined to be due to the simultaneous presence of Mn⁺³ and Mn⁺⁴ ions at the Zn diffusion front into the manganese oxide grain. Thus, it is demonstrated that Mn does not incorporate into the ZnO lattice substitutionally, but it is the Zn that diffuses into the manganese oxide grains, acting as a retardant of the manganese reduction, Mn⁺⁴ → Mn⁺³. At the diffusion front, both ions coexist and their spins couple ferromagnetically through a double exchange mechanism. This mechanism explains the origin of the room temperature ferromagnetism recently discovered in Zn–Mn–O system as a promising material for spintronic devices.     

Near-infrared emitting CdTe0.5Se0.5/Cd0.5Zn0.5S quantum dots: synthesis and bright luminescence

We present how CdTe_0.5Se_0.5 cores can be coated with Cd_0.5Zn_0.5S shells at relatively low temperature (around 200°C) via facile synthesis using organic ammine ligands. The cores were firstly fabricated via a less toxic procedure using CdO, trioctylphosphine (TOP), Se, Te, and trioctylamine. The cores with small sizes (3.2-3.5 nm) revealed green and yellow photoluminescence (PL) and spherical morphologies. Hydrophobic core/shell CdTe_0.5Se_0.5/Cd_0.5Zn_0.5S quantum dots (QDs) with tunable PL between green and near-infrared (a maximum PL peak wavelength of 735 nm) were then created through a facile shell coating procedure using trioctylphosphine selenium with cadmium and zinc acetate. The QDs exhibited high PL efficiencies up to 50% because of the formation of a protective Cd_0.5Zn_0.5S shell on the CdTe_0.5Se_0.5 core, even though the PL efficiency of the cores is low (≤1%). Namely, the slow growth process of the shell plays an important role for getting high PL efficiencies. The properties of the QDs are largely determined by the properties of CdTe_0.5Se_0.5 cores and shells preparation conditions such as reaction temperature and time. The core/shell QDs exhibited a small size diameter. For example, the average diameter of the QDs with a PL peak wavelength of 735 nm is 6.1 nm. Small size and tunable bright PL makes the QDs utilizable as bioprobes because the size of QD-based bioprobes is considered as the major limitation for their broad applications in biological imaging.