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oe1(光电查) - 科学论文

100 条数据
?? 中文(中国)
  • Hybridization induced fluorescence enhanced DNA-Ag nanocluster/aptamer probe for detection of prostate-specific antigen

    摘要: In this work, a label-free Ag nanocluster (AgNC)-based fluorescent probe is proposed to detect tumor marker, prostate-specific antigen (PSA). In the experiments, DNA sequences containing segments complemented to different parts of PSA aptamer were used to synthesize DNA-Ag nanoclusters (DNA-AgNC). Some of the obtained specific DNA-AgNC exhibited significant fluorescence increase after hybridization with PSA aptamer. Based on this, a simple DNA-AgNC/aptamer hybridization probe was fabricated for PSA detection using fluorescence quenching, because competitively specific binding between PSA and its aptamer inhibited the fluorescence enhancement effect of PSA aptamer on DNA-AgNC. The sequence of template DNA, pH and salt concentration of binding buffer, and the concentration of aptamer were optimized. Under optimum conditions, the concentration of PSA within the range of 2–150 ng mL?1 with the detection limit of 1.14 ng mL?1 was detected (3σ; n = 7). This approach was also successfully applied to determine PSA in spiked serum samples. As is well known, this was the first report to realize PSA detection using fluorescent AgNC-based probe. This work would provide reference for construction of AgNC-based probes for detecting other proteins.

    关键词: DNA-AgNC fluorescent probe,Ag nanocluster,Prostate-specific antigen,Aptamer

    更新于2025-09-04 15:30:14

  • Iminocoumarin-based red to near-infrared fluorescent turn-on probe with a large Stokes shift for imaging H2S in living cells and animals

    摘要: The development of organic dye-based fluorescent probes for detection of H2S in living systems has attracted considerable attention in recent years. In this work, a novel tetrahydroquinoxaline iminocoumarin-based red to near-infrared (red-to-NIR) fluorescent probe was developed for detection of H2S. This probe shows a rapid and distinct red-to-NIR fluorescent turn-on detection process for H2S with high selectivity and sensitivity (the detection limit was determined to be as low as 10 nM at physiological pH). In addition, this probe exhibits a remarkable large Stokes shift (128 nm) and low cytotoxicity, and can be applied for imaging H2S in living cells and animals. All these results demonstrated that this new probe is promising for detection of H2S both in vitro and in vivo.

    关键词: large Stokes shift,hydrogen sulfide,living cells and animals,near-infrared fluorescent probe,iminocoumarin

    更新于2025-09-04 15:30:14

  • A colorimetric and ratiometric fluorescent probe with ultralow detection limit and high selectivity for phosgene sensing

    摘要: Phosgene is a kind of colourless and extreme toxic gas that poses a serious threat to public health and safety. A colorimetric and ratiometric fluorescent probe (AC-6ED), with anthracene carboximide as fluorophore and ethylenediamine group as recognition moiety has been developed for phosgene detection in solutions and in the gas phase based on the intramolecular charge transfer (ICT) mechanism. The AC-6ED traps phosgene molecule via intramolecular cyclization reaction to afford color and fluorescence emission change. The AC-6ED features low detection limit (0.09 nM), fast response (< 20 s), remarkable colorimetric and ratiometric signal, excellent selectivity for phosgene over other interference analytes such as nerve agent mimics, various acyl chlorides and analogues. The AC-6ED loaded TLC plate can serve as a highly selective tool for phosgene sensing in the gas phase below health risk concentrations in a fast, portable, visible, and highly sensitive manner.

    关键词: ratiometric fluorescence,phosgene,fluorescent probe,anthracene carboximide

    更新于2025-09-04 15:30:14

  • A Two-Photon Ratiometric Probe for Hydrogen Polysulfide (H2Sn): Increase in Mitochondrial H2Sn Production in a Parkinson’s Disease Model

    摘要: Hydrogen polysulfide (H2Sn, n>1), which is primarily generated during the crosstalk between H2S and reactive species (ROS and RNS), is receiving increasing attention in biochemical research. H2Sn is mostly generated in the mitochondria, and abnormal mitochondrial function and oxidative stress are directly related to many disorders including Parkinson's disease (PD). We now report a two-photon fluorescent probe (SPS-M1) for in situ detection of H2Sn and its application to a PD model to account the H2Sn levels. The probe exhibited selective and fast response to H2Sn along with a marked blue-to-green color change. SPS-M1 is sensitive enough to quantitative detection of endogenous H2Sn content in mitochondria using two-photon microscopy (TPM). Ratiometric TPM imaging of live neurons and brain slices using SPS-M1 revealed that H2Sn production is increased to a greater extent in the A53T α-synuclein (α-syn) overexpressing model than in the wild-type control. These findings suggest that the interactions of H2S and the increased ROS caused by α-syn overexpression may generate more H2Sn. By employing our recently published TP probe for mitochondrial H2S, we also found the relationship between the H2Sn and H2S; increased H2Sn and decreased H2S levels, indicating that H2S and H2Sn may play a significant role in the pathogenesis of PD. This result may be useful to biomedical studies, including PD.

    关键词: two-photon microscopy,fluorescent probe,Parkinson’s disease,Hydrogen polysulfide,mitochondria

    更新于2025-09-04 15:30:14

  • A molecular design strategy to construct the near-infrared fluorescent probe for selectively sensing human cytochrome P450 2J2

    摘要: Cytochrome P450 2J2 (CYP2J2), a key enzyme responsible for oxidative metabolism of various xenobiotics and endogenous compounds, participates in a diverse array of physiological and pathological processes in humans. Its biological role in tumorigenesis and cancer diagnosis remains poorly understood, owing to the lack of molecular tools suitable for real-time monitoring CYP2J2 in complex biological systems. Using molecular design principles we were able to modify the distance between the catalytic unit and metabolic recognition moiety, allowing us to develop a CYP2J2 selective fluorescent probe using a near-infrared fluorophore (E)-2-(2-(6-hydroxy-2, 3-dihydro-1H-xanthen-4-yl)vinyl)-3,3-dimethyl-1-propyl-3H-indol-1-ium iodide (HXPI). To improve the reactivity and isoform specificity, a self-immolative linker was introduced to the HXPI derivatives in order to better fit the narrow substrate channel of CYP2J2, the modification effectively shortened the spatial distance between the metabolic moiety (O-alkyl group) and catalytic center of CYP2J2. After screening a panel of O-alkylated HXPI derivatives, BnXPI displayed the best combination of specificity, sensitivity and applicability for detecting CYP2J2 in vitro and in vivo. Upon O-demethylation by CYP2J2, a self-immolative reaction occurred spontaneously via 1,6-elimination of p-hydroxybenzyl resulting in the release of HXPI. Allowing BnXPI to be successfully used to monitor CYP2J2 activity in real-time for various living systems including cells, tumor tissues, and tumor-bearing animals. In summary, our practical strategy could help the development of a highly specific and broadly applicable tool for monitoring CYP2J2, which offers great promise for exploring the biological functions of CYP2J2 in tumorigenesis.

    关键词: Cytochrome P450 2J2,near-infrared fluorescent probe,real-time monitoring,molecular design,CYP2J2,tumorigenesis

    更新于2025-09-04 15:30:14

  • Dicyanoisophorone-Based Near-Infrared Emission Fluorescent Probe for Detecting NAD(P)H in Living Cells and <i>in Vivo</i>

    摘要: NADH and NADPH are ubiquitous coenzymes in all living cells and play vital roles in numerous redox reactions in cellular energy metabolism. To accurately detect the distribution and dynamic changes of NAD(P)H under physiological condition is essential for understanding its biological functions and pathological roles. In this work, we developed a near-infrared (NIR) emission fluorescent small-molecule probe (DCI-MQ) composed of a dicyanoisophorone chromophore conjugated with a quinolinium moiety for in vivo NAD(P)H detection. DCI-MQ owns the advantages of high water solubility, rapid response, extraordinary selectivity, great sensitivity (detection limit of 12 nM), low cytotoxicity and a NIR emission (660 nm) in response to NAD(P)H. Moreover, the probe DCI-MQ was successfully applied for the detection and imaging of endogenous NAD(P)H in both living cells and tumor-bearing mice, which provides an effective tool for the study of NAD(P)H-related physiological and pathological processes.

    关键词: NAD(P)H,near-infrared emission,fluorescent probe,bioimaging,dicyanoisophorone

    更新于2025-09-04 15:30:14

  • Selectively light-up hydrogen peroxide in hypoxic cancer cells with a novel fluorescent probe

    摘要: A novel fluorescent turn-on probe (HCyHP) was developed in a simple two-step synthesis for monitoring of exogenous and endogenous H2O2 levels in biological samples and hypoxic cancer diagnosis.

    关键词: hypoxic cancer cells,fluorescent probe,hydrogen peroxide,bioimaging,diagnosis

    更新于2025-09-04 15:30:14

  • Fluorescence-Guided Cancer Diagnosis and Surgery by a Zero Cross-Talk Ratiometric Near-Infrared γ-Glutamytranspeptidase Fluorescent Probe

    摘要: The ability to early detect cancer in an accurate and rapid fashion is of critical importance for cancer diagnosis and accurate resection in surgery. γ-Glutamyltranspeptidase (GGT) is overexpressed in several human cancers while keeps low expression in normal microenvironment, and thus recognized as an important cancer biomarker. To date, rational design of a zero cross-talk ratiometric near-infrared (NIR) GGT fluorescent probe for efficiently cancer diagnosis in various biological samples is still a big challenge. In this work, a zero cross-talk ratiometric NIR GGT fluorescent probe named Cy-GSH is developed. Cy-GSH shows highly sensitive to GGT, which is desired for cancer early diagnosis. Upon additional GGT, a large emission shift from 805 nm to 640 nm is observed, which is suitable for visualizing deeply located cancer in vivo. In addition, successful monitoring GGT activity in bloods, cells, tissues and in vivo, makes Cy-GSH possess great potentials for the clinical cancer early diagnosis. Furthermore, accurate visualizing tumors and metastases in mouse models illuminates that the probe may be a convenient tool for fluorescence-guided cancer surgery. To our knowledge, this is the first report to describe the strategy of a zero cross-talk ratiometric NIR GGT fluorescent probe for cancer early diagnosis and fluorescence-guided surgery.

    关键词: fluorescent probe,γ-Glutamyltranspeptidase,GGT,cancer diagnosis,fluorescence-guided surgery

    更新于2025-09-04 15:30:14

  • A ratiometric fluorescent probe for hydrazine detection with large fluorescence change ratio and its application for fluorescence imaging in living cells

    摘要: Hydrazine and its derivatives are one of the most important raw chemical materials that have extensive utilization in many areas. It is also widely applied as pharmaceutical derivatives, such as the antipsychotic drug, anti-infective drug, and antitumor drug. However, hydrazine is a highly toxic reagent which can bring severe damage to human and animals. Herein, we have reported a new benzothiazole substituted naphthalene based probe for hydrazine with huge fluorescence change ratio. The fluorescence change ratio at F390/F509 is up to 200-fold in the presence of hydrazine in 60 min. The probe exhibited negligible cytotoxicity toward HeLa cells and was applied for hydrazine detection successfully in HeLa cells.

    关键词: Fluorescent probe,ratiometric,cell imaging,hydrazine detection

    更新于2025-09-04 15:30:14

  • Co-localization coefficients of a target-switchable fluorescent probe can serve as an indicator of mitochondrial membrane potential

    摘要: The mitochondrial membrane potential (MMP) definitely reflects mitochondrial function. Thus, it is very essential to found a physical parameter as MMP indicator. At present, available parameters are either fluorescent intensity of monochromatic probes such as rhodamine 123 or a ratio of fluorescent intensity at different wavelengths of dual-color dyes such as JC-1, but the inconvenience in practice as well as serious effect of loading concentrations on experimental results limited their application. To address this concern, herein, we found a reliable and easily obtainable co-localization coefficient (CLC) of a fluorescent probe as new MMP indicator and developed a target switchable fluorescent probe (Mito-Lyso) to attain the aim. Due to intrinsic nature, Mito-Lyso exclusively stains mitochondria with normal MMP and a subsequent decreasing of MMP results in release of some Mito-Lyso. Importantly, the released Mito-Lyso can reversibly transfer between mitochondria and lysosomes. Thus, CLCs of Mito-Lyso and a commercial lysosomal probe (NIR-Lyso) can be MMP-dependent. CLCs gradually increased from 0.20 to 0.8 with the decreasing of MMP and then returned to 0.3 with the recovering of MMP, which better proves that the CLC is a valuable MMP indicator. Furthermore, both the design principle and action mechanism of Mito-Lyso has been explained in detail for the development of this type of probes.

    关键词: Mito-Lyso,fluorescent probe,co-localization coefficient,mitochondrial membrane potential,target-switchable

    更新于2025-09-04 15:30:14