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oe1(光电查) - 科学论文

110 条数据
?? 中文(中国)
  • Bright red-emitting highly reliable styryl probe with large stokes shift for visualizing mitochondria in live cells under wash-free conditions

    摘要: Bright red-emitting pyridinium cyanine based styryl probe 2 is synthesized in good yields. Probe 2 demonstrated a large Stokes’ shift (Δλ ≈ 128 nm, 4227 cm-1 in DCM) and excellent fluorescent quantum yield (?fl ≈ 0.2 - 0.7) due to strong Intra-molecular charge transfer (ICT). Probe 2 found to exhibit exceptional selectivity for cellular mitochondria in both normal (COS-7) and cancer (A549) cell lines. Probe 2 is readily applicable as a “wash-free” dye to visualize mitochondria as it does not require post-staining washing prior to imaging. Styryl probe 2 also showed an excellent biocompatibility as the calculated LC50 (lethal concentration, 50%) value was > 20 μM. Probe 2 emission did not show any interferences from anionic species or other biological molecules. Probe 2 is readily excitable (λex ~460 and λem ~618 nm) with the available laser (454 nm) in commercial microscopes and thus it can be a useful probe for mitochondrial tracking in live cells.

    关键词: Wash-free application,Biocompatibility,Intra-molecular charge transfer (ICT),Styryl dye,Large Stokes shift,Mitochondria selectivity

    更新于2025-09-23 15:23:52

  • A highly sensitive photocatalytic plastic optic-fiber sensor for selective detection of phenol in aqueous solutions

    摘要: We present a highly sensitive photocatalytic plastic optic-fiber (POF) sensor for the selective detection of phenol in aqueous solutions. To obtain high sensitivity and low limit of detection (LOD) of the sensor, part of the POF cladding was removed and replaced by a Canada balsam doped with GeO2 (CBG); a UV-visible-light-driven photocatalytic material, that is a CdS-sensitized Er3+YAlO3/SiO2/TiO2 (EYST) composite, was coated on the CBG film. To realize highly selective detection of phenol in water, a high phenol permselectivity and pH independence polymer membrane was fixed on the CdS-sensitized EYST-CBG-coated POF. Furthermore, a model was developed to show that the phenol concentration can be determined by measuring the change in transmitted light intensity of the POF sensor and the sensitivity of the sensors can be improved by employing the CdS-sensitized EYST film. The results showed that the proposed photocatalytic POF sensor has a high sensitivity of -0.39 (mg·mL-1)-1 and low LOD of 15 μg·L-1 for the selective detection of phenol in aqueous solutions with pH ranging from 2.0 to 14.0.

    关键词: Cds sensitization,Phenol concentration,High sensitivity and selectivity,Upconversion luminescence agent,Plastic optical fiber,TiO2 composite film

    更新于2025-09-23 15:23:52

  • Highly Sensitive and Selective PbTiO3 Gas Sensors with Negligible Humidity Interference in Ambient Atmosphere

    摘要: Three PbTiO3 nanostructures were synthesized using a one-step hydrothermal reaction with different TiO2 powders as Ti sources, and their gas sensing properties were investigated. The sensor comprising PbTiO3 nanoplates exhibited a high response (resistance ratio = 80.4) to 5 ppm ethanol at 300 °C and could detect trace concentrations of ethanol down to 100 ppb. Moreover, the sensor showed high ethanol selectivity and nearly the same sensing characteristics despite the wide range of humidity variation from 20% RH to 80% RH. The mechanism for humidity-independent gas sensing was elucidated using the diffuse reflectance infrared Fourier transform spectra. PbTiO3 nanoplates are new and promising sensing materials that can be used for detecting ethanol in a highly sensitive and selective manner with negligible interference from ambient humidity.

    关键词: selectivity,ethanol,PbTiO3 nanoplate,gas sensor,humidity interference

    更新于2025-09-23 15:23:52

  • [IEEE 2018 IEEE Life Sciences Conference (LSC) - Montreal, QC, Canada (2018.10.28-2018.10.30)] 2018 IEEE Life Sciences Conference (LSC) - Aptamers-Based Gold-Micro-Array for High-Selective Detection of Bacteria Using Fluorescence Microscopy

    摘要: The monitoring of Escherichia coli (E. coli) bacteria in food and water is an effective preventive measure in controlling the outbreaks of serious food-related diseases. Moreover, the accurate detection of its early stage of the bacteria can ensure the public health and safety. In this study, a target-selective aptamer-based platform is proposed as a reliable procedure for the detection of the E. coli in Phosphate-buffered saline (PBS) using fluorescent microscopy. The results show that the aptamer sequences, immobilized on an array of Au-micro-squares, are very high selective towards the target bacteria cells. This platform, presented for the first time, can be potentially used to detect different kinds of cells simultaneously. Also, an important cell-counting application, based on Neubauer Lam high accuracy method, is proposed and implemented and validated by experimental results.

    关键词: Fluorescent microscope,Selectivity,E. coli detection,Aptamer

    更新于2025-09-23 15:22:29

  • Selective Gas Sensor Using Porous Silicon

    摘要: The effect of polar and non-polar vapors, like ethanol, methanol, acetonitrile, chloroform and toluene vapors on porous silicon gas sensor was studied. We demonstrated that the selectivity of a single sensor can be achieved by the impedance measurements within the frequency range 103–105 Hz. It is shown that the capacitance of the structure and its frequency dispersion are different under influence of different gases providing an unique signature of an agent. A set of parameters is proposed in order to numerically characterize the response to different gases. The characteristic time of response to different vapors gives an additional parameter to sense gases selectively.

    关键词: Organic Vapors,Gas Sensor,Porous Silicon,Selectivity

    更新于2025-09-23 15:22:29

  • A Sensitive Near-Infrared Fluorescent Probe for Detecting Heavy Metal Ag+ in Water Samples

    摘要: Silver is a common catalyst in industrial production, and the frequent use of Ag+ can cause water pollution. Thus, the detection of Ag+ in the environment is necessary to determine the level of pollution from silver. In this work, we designed a new, highly selective near-infrared (NIR) fluorescent probe QCy to detect Ag+. The probe exhibits 'turn-off' fluorescence quenching responses at 760 nm towards Ag+ over other relevant cations, with outstanding sensitivity and a low detection limit (0.03 μM), which is considerably lower than the standard of the World Health Organization (WHO) for drinking water (0.9 μM). Meanwhile, QCy showed a very good linearity at a low concentration of Ag+ with a 'naked eye' visible color change of solution from blue to red. The probe has been applied successfully for the detection of Ag+ in real water samples.

    关键词: selectivity,fluorescence probe,Ag+,sensitivity,water samples

    更新于2025-09-23 15:22:29

  • A novel “turn-on” mitochondria-targeting near-infrared fluorescent probe for H2S detection and in living cells imaging

    摘要: Hydrogen sulfide (H2S) has been considered to be involved in cytoprotective processes and redox signaling. It is very meaningful to track and analyze it in mitochondria. Herein, we report a novel “turn-on” mitochondria-targeting near-infrared fluorescent probe (Mito-NIR-SH) for detection of H2S in living cells, which was designed and synthesized by introducing 2,4-dinitrophenyl as fluorescence quenching group and H2S response moiety into Changsha near-infrared fluorophore (CS-OH). The structure of the fluorophore and the probe were characterized by 1H NMR, 13C NMR and mass spectrometry. Meanwhile, Mito-NIR-SH could quantitatively detect H2S at concentrations ranging from 0 to 30 μM with a detection limit as low as 89.3 nM, showing good chemical stability, fast “turn-on” response, selectively mitochondrial location, as well as high sensitivity and selectivity toward H2S. Based on this, it was successfully applied to imaging exogenous and endogenous H2S in living HeLa cells via confocal fluorescence microscopy.

    关键词: High sensitivity and selectivity,Near-infrared fluorescent probe,Hydrogen sulfide,Mitochondria-targeting,Bioimaging

    更新于2025-09-23 15:22:29

  • Monometallic Catalytic Models Hosted in Stable Metal-Organic Frameworks for Tunable CO2 Photoreduction

    摘要: The photocatalytic reduction of CO2 to energy carriers has emerged as one of the most promising strategy to alleviate the energy crisis and CO2 pollution, for which the development of catalyst was considered as the determining factor for the accomplishment of this conversion process. In this study, three stably and isostructural metal organic frameworks (denoted as MOF-Ni, MOF-Co and MOF-Cu), have been synthesized and used as heterogeneous catalysts applied into photocatalytic CO2 reduction reaction (CO2RR). It is worth noting that the MOF-Ni exhibited a very high selectivity of 97.7% for photoreducing CO2 to CO, which has exceeded most of the reported MOF-based catalysts in the field. Significantly, the MOFs associated with monometallic catalytic centre offer a simply and precisely structural model which allows us to understand the specific effects of different metal ion species on photoreduction of CO2 as well as reactive mechanism more intuitively.

    关键词: Isostructural,Metal-Organic Frameworks,Photocatalytic CO2 Reduction,High Selectivity,Monometallic Catalytic Model,Reactive Mechanism

    更新于2025-09-23 15:22:29

  • [IEEE 2018 19th International Conference on Electronic Packaging Technology (ICEPT) - Shanghai (2018.8.8-2018.8.11)] 2018 19th International Conference on Electronic Packaging Technology (ICEPT) - Bosch Etching Study with Large Open Rate and Depth Application

    摘要: With the development of semiconductor technology, Bosch etching technology is more and more used in 2.5D multi-die integration and 3D wafer level chip size package. Bosch etching can get a vertical via with anisotropic, which helps to promote miniaturization. Bosch etching process has a new challenge for large open rate and depth applications, such as PCR (polymerase chain reaction) chip and optical fingerprint chip scale package. This paper introduces some experiments with optimizing parameters, including chuck temperature, photo resist layer thickness and bias power. In this study, it is successful to develop a through-hole with 45% open rate and 350 um depth. The selectivity can be above 30:1 with 17 um photo resist layer under 5℃ chuck temperature. The etch rate can be 4.6 um/min with 3.1% uniformity in a good profile. At the same time, the scallop is about 50 nm. The bottom via open is 3 um larger than the top via with 51 um.

    关键词: selectivity,uniformity,large open rate and depth,via side,etch rate,Bosch etching

    更新于2025-09-23 15:22:29

  • Highly Selective Photocatalytic Reduction of o-Dinitrobenzene to o-Phenylenediamine over Non-Metal-Doped TiO2 under Simulated Solar Light Irradiation

    摘要: Photocatalytic reduction and hydrogenation reaction of o-dinitrobenzene in the presence of oxalic acid over anatase-brookite biphasic TiO2 and non-metal-doped anatase-brookite biphasic TiO2 photocatalysts under solar simulated light was investigated. Compared with commercial P25 TiO2, the prepared un-doped and doped anatase-brookite biphasic TiO2 exhibited a high selectivity towards the formation of o-nitroaniline (85.5%) and o-phenylenediamine ~97%, respectively. The doped anatase-brookite biphasic TiO2 has promoted photocatalytic reduction of the two-nitro groups of o-dinitrobenzene to the corresponding o-phenylenediamine with very high yield ~97%. Electron paramagnetic resonance analysis, Transient Absorption Spectroscopy (TAS) and Photoluminescence analysis (PL) were performed to determine the distribution of defects and the fluorescence lifetime of the charge carriers for un-doped and doped photocatalysts. The superiority of the doped TiO2 photocatalysts is accredited to the creation of new dopants (C, N, and S) as hole traps, the formation of long-lived Ti3+ defects which leads to an increase in the fluorescence lifetime of the formed charge carriers. The schematic diagram of the photocatalytic reduction of o-dinitrobenzene using the doped TiO2 under solar light was also illustrated in detail.

    关键词: selectivity,photocatalysis,non-metal-doped TiO2,nitroaromatic compounds,reduction

    更新于2025-09-23 15:22:29