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oe1(光电查) - 科学论文

5 条数据
?? 中文(中国)
  • Synthesis of Fluorescent Ag Nanoclusters for Sensing and Imaging Applications

    摘要: Metal nanoparticles have attracted more and more attention in the last years due to their unique chemical and physical properties which are very different from the metal bulk material. In particular, when the size of nanoparticles decreases below two nm, nanoparticles can be described as nanoclusters (NCs), and they present peculiar optical properties. The excited electrons in addition to specific absorption bands show also a bright luminescence related to the quantum size effect which produce discrete energy levels. Optical properties (absorption and fluorescence) of these NCs are widely used in many different applications in science and engineering, such as chemical sensors, fluorescent probes for bio imaging or in environmental issues. In the present study, we report on the synthesis of silver nanoclusters (AgNCs) in aqueous phase using silver nitrate as precursor salt and L-Glutathione (GSH) as stabilizer. AgNCs were characterized using absorption and fluorescence spectroscopy, and transmission electron microscopy (TEM). The strong absorption and luminescence shown by these NCs are very promising for a possible exploitation both as label for bioimaging and for optical sensors for heavy metal ions.

    关键词: luminescence,spectroscopy,GSH-Ag Nanoclusters,optical absorption

    更新于2025-09-23 15:23:52

  • MPA-GSH functionalized AlGaN/ GaN High Electron Mobility Transistor based sensor for Cadmium ion detection

    摘要: This work demonstrates a novel AlGaN/GaN high electron mobility transistor (HEMT) based cadmium ion (Cd2+) sensor with Mercaptopropionic Acid (MPA) and Glutathione (GSH) functionalization. The sensing response of the sensor was analysed by detecting Cd2+ ions at different concentrations. The AlGaN/GaN HEMT sensor exhibits excellent response with the sensitivity of 0.241 μA/ppb, a fast response time of ~ 3 seconds and a lower detection limit of 0.255 ppb. The observed lower detection limit is significantly lower than the World Health Organization (WHO) standard recommended limit for Cd2+ ions in drinking water. Furthermore, the sensor showed good selectivity of Cd2+ ions towards other heavy metal ions. The results indicate that the binding properties of GSH to Cd and the sensitivity of 2-D electron gas (2DEG) towards the variation of charges at the gate region makes the device highly sensitive with rapid detection of Cd2+ ions.

    关键词: MPA,Cd2+ ions,AlGaN/GaN HEMT,sensing,GSH

    更新于2025-09-23 15:22:29

  • Synthesis of Water Soluble CuGaS2/ZnS Quantum Dots for Ultrasensitive Fluorescent Detection of Alkaline Phosphatase Based on Inner Filter Effect

    摘要: Developing monitoring technique for alkaline phosphatase (ALP) is crucial due to the important role it plays in living cells. Here, a kind of biocompatible glutathione-modified CuGaS2/ZnS quantum dots (GSH-CGS/ZnS QDs) was used as a fluorescent substance and then fabricated “turn-off” fluorescent biosensor for detection of ALP by help of inner filter effect (IFE). Firstly, we prepared CuGaS2/ZnS (CGS/ZnS) QDs using solvothermal method and explored the efficient ligand (GSH) exchanges strategy for transferring oil-soluble CGS/ZnS QDs to aqueous phase. More importantly, we also explored the potential biological applications of the nanohybrid QDs. The obtained GSH-CGS/ZnS QDs emitted strong yellow fluorescence with the maximum excitation (400 nm) and emission (601 nm). Then, GSH-CGS/ZnS QDs were mixed with p-nitrophenylphosphate (PNPP) and ALP. PNPP could be hydrolyzed to p-nitrophenol (PNP) by help of catalysis of ALP, and the excitation spectrum of the GSH-CGS/ZnS QDs overlapped well with the absorption spectrum of PNP, so the fluorescence of GSH-CGS/ZnS QDs was initially quenched via the so-called “IFE”. Finally, a novel “turn-off” biosensor for sensitive detection of ALP in the range of 0.05-10 U L -1(R2 = 0.98) with a detection limit of 0.01 U L-1 was successfully obtained. Results indicated that I-III-VI2 nanocrystals have great potential for their promising biomedical application.

    关键词: Inner filter effect,Alkaline phosphatase,GSH-CuGaS2/ZnS QDs,Fluorescent detection,Water solubility and biocompatibility

    更新于2025-09-23 15:19:57

  • Influence of size and surface capping on photoluminescence and cytotoxicity of gold nanoparticles

    摘要: Hydrophilic and homogeneous sub-10 nm blue light-emitting gold nanoparticles (NPs) functionalized with different capping agents have been prepared by simple chemical routes. Structure, average, size, and surface characteristics of these NPs have been widely studied, and the stability of colloidal NP solutions at different pH values has been evaluated. Au NPs show blue PL emission, particularly in the GSH capped NPs, in which the thiol-metal core transference transitions considerably enhance the fluorescent emission. The influence of capping agent and NP size on cytotoxicity and on the fluorescent emission are analyzed and discussed in order to obtain Au NPs with suitable features for biomedical applications. Cytotoxicity of different types of gold NPs has been determined using NPs at high concentrations in both tumor cell lines and primary cells. All NPs used show high biocompatibility with low cytotoxicity even at high concentration, while Au-GSH NPs decrease viability and proliferation of both a tumor cell line and primary lymphocytes.

    关键词: Semiconfocal microscopy,Photoluminescence,Capping,Cell viability,GSH,Gold nanoparticles,Agent,Proliferation,Cytotoxicity

    更新于2025-09-10 09:29:36

  • Colorimetric and NIR fluorescence probe with multiple binding sites for distinguishing detection of Cys/Hcy and GSH in vivo

    摘要: Although some progress has been made in distinguishing detection of biothiols, NIR biothiol fluorescent probes for simultaneous distinguishing detection of Cys, Hcy and GSH in vivo have not been reported. The design of these probes involves the introduction of NIR fluorophores and multiple binding sites, so the integrated design of probes remains a challenge. Although Cys, Hcy and GSH have the common functional group: a sulfydryl group and an amino group, due to their differences in spatial structure, they may react with multiple binding sites probes to produce different reaction products in different bonding mechanisms, resulting in the different colors and fluorescent signals changes of the system. Therefore, multiple binding sites fluorescent probes can realize their discrimination detection. For NIR fluorescent probe, it is easier to realize in vivo imaging to promote the research of biothiols in clinical diagnosis. In our work, not only multiple binding sites were constructed in the compound, but also NIR fluorophores were introduced. This enables the probe to not only efficiently distinguish detection of Cys/Hcy and GSH but also achieve fluorescence imaging in vivo. We believe this result is a milestone in the discrimination detection of biothiols.

    关键词: Cys/Hcy,in vivo,NIR fluorescence probe,GSH,Colorimetric,multiple binding sites

    更新于2025-09-09 09:28:46