The Experts below are selected from a list of 18798 Experts worldwide ranked by ideXlab platform
Wei Huang - One of the best experts on this subject based on the ideXlab platform.
-
organic Nanoprobe cocktails for multilocal and multicolor fluorescence imaging of reactive oxygen species
Advanced Functional Materials, 2017Co-Authors: Chao Yin, Houjuan Zhu, Chen Xie, Lei Zhang, Peng Chen, Quli Fan, Wei HuangAbstract:Hypochlorite (ClO−) as a highly reactive oxygen species not only acts as a powerful “guarder” in innate host defense but also regulates inflammation-related pathological conditions. Despite the availability of fluorescence probes for detection of ClO− in cells, most of them can only detect ClO− in single cellular organelle, limiting the capability to fully elucidate the synergistic effect of different organelles on the generation of ClO−. This study proposes a Nanoprobe cocktail approach for multicolor and multiorganelle imaging of ClO− in cells. Two semiconducting oligomers with different π-conjugation length are synthesized, both of which contain phenothiazine to specifically react with ClO− but show different fluorescent color responses. These sensing components are self-assembled into the Nanoprobes with the ability to target cellular lysosome and mitochondria, respectively. The mixture of these Nanoprobes forms a nano-cocktail that allows for simultaneous imaging of elevated level of ClO− in lysosome and mitochondria according to fluorescence color variations under selective excitation of each Nanoprobe. Thus, this study provides a general concept to design probe cocktails for multilocal and multicolor imaging.
Chao Yin - One of the best experts on this subject based on the ideXlab platform.
-
organic Nanoprobe cocktails for multilocal and multicolor fluorescence imaging of reactive oxygen species
Advanced Functional Materials, 2017Co-Authors: Chao Yin, Houjuan Zhu, Chen Xie, Lei Zhang, Peng Chen, Quli Fan, Wei HuangAbstract:Hypochlorite (ClO−) as a highly reactive oxygen species not only acts as a powerful “guarder” in innate host defense but also regulates inflammation-related pathological conditions. Despite the availability of fluorescence probes for detection of ClO− in cells, most of them can only detect ClO− in single cellular organelle, limiting the capability to fully elucidate the synergistic effect of different organelles on the generation of ClO−. This study proposes a Nanoprobe cocktail approach for multicolor and multiorganelle imaging of ClO− in cells. Two semiconducting oligomers with different π-conjugation length are synthesized, both of which contain phenothiazine to specifically react with ClO− but show different fluorescent color responses. These sensing components are self-assembled into the Nanoprobes with the ability to target cellular lysosome and mitochondria, respectively. The mixture of these Nanoprobes forms a nano-cocktail that allows for simultaneous imaging of elevated level of ClO− in lysosome and mitochondria according to fluorescence color variations under selective excitation of each Nanoprobe. Thus, this study provides a general concept to design probe cocktails for multilocal and multicolor imaging.
Niko Hildebrandt - One of the best experts on this subject based on the ideXlab platform.
-
Time‐Gated FRET Nanoprobes for Autofluorescence‐Free Long‐Term In Vivo Imaging of Developing Zebrafish
Advanced Materials, 2020Co-Authors: Marcelina Cardoso Dos Santos, Ingrid Colin, Gabriel Ribeiro Dos Santos, Kimihiro Susumu, Michael Demarque, Igor Medintz, Niko HildebrandtAbstract:The zebrafish is an important vertebrate model for disease, drug discovery, toxicity, embryogenesis, and neuroscience. In vivo fluorescence microscopy can reveal cellular and subcellular details down to the molecular level with fluorescent proteins (FPs) currently the main tool for zebrafish imaging. However, long maturation times, low brightness, photobleaching, broad emission spectra, and sample autofluorescence are disadvantages that cannot be easily overcome by FPs. Here, a bright and photostable terbium‐to‐quantum dot (QD) Förster resonance energy transfer (FRET) Nanoprobe with narrow and tunable emission bands for intracellular in vivo imaging is presented. The long photoluminescence (PL) lifetime enables time‐gated (TG) detection without autofluorescence background. Intracellular four‐color multiplexing with a single excitation wavelength and in situ assembly and FRET to mCherry demonstrate the versatility of the TG‐FRET Nanoprobes and the possibility of in vivo bioconjugation to FPs and combined Nanoprobe‐FP FRET sensing. Upon injection at the one‐cell stage, FRET Nanoprobes can be imaged in developing zebrafish embryos over seven days with toxicity similar to injected RNA and strongly improved signal‐to‐background ratios compared to non‐TG imaging. This work provides a strategy for advancing in vivo fluorescence imaging applications beyond the capabilities of FPs.
Weihong Tan - One of the best experts on this subject based on the ideXlab platform.
-
nitric oxide activated dual key one lock Nanoprobe for in vivo molecular imaging and high specificity cancer therapy
Journal of the American Chemical Society, 2019Co-Authors: Lili Teng, Xiaobing Zhang, Guosheng Song, Yongchao Liu, Xiao Han, Youjuan Wang, Shuangyan Huan, Weihong TanAbstract:Cancer treatments are confounded by severe toxic effects toward patients. To address these issues, activatable Nanoprobes have been designed for specific imaging and destruction of cancer cells under the stimulation of specific cancer-associated biomarkers. Most activatable Nanoprobes were usually activated by some single-factor stimulation, but this restricts therapeutic specificity between diseased and normal tissue; therefore, multifactor activation is highly desired. To this end, we herein develop a novel dual-stimuli responsive theranostic Nanoprobe for simultaneously activatable cancer imaging and photothermal therapy under the coactivation of "dual-key" stimulation of "nitric oxide (NO)/acidity", so as to further improve the therapeutic specificity. Specifically, we have integrated a weak electron acceptor (benzo[c][1,2,5]thiadiazole-5,6-diamine) into a donor-π-acceptor-π-donor type chromophore. When the weak acceptor was oxidized by NO in acidic conditions to form a stronger acceptor (5H-[1,2,3]triazolo[4,5-f]-2,1,3-benzothiadiazole), the molecule absorption was significantly increased in the near-infrared region, based on the intramolecular charge transfer (ICT) mechanism. Under the dual-key stimulation of NO/acidity within the tumor associated with inflammation, the Nanoprobe can correspondingly output dual signals for ratiometric photoacoustic and photothermal imaging of cancer in vivo and do so with enhanced accuracy and specificity. Our novel Nanoprobe exhibited higher photoacoustic signal enhancement under dual-factor activation at 9.8 times that of NO and 132 times that of acidity alone, respectively. Moreover, through such dual activation of NO/acidity, the Nanoprobe produces more differentiation of hyperthermia between tumor and normal tissues, to afford satisfactory photothermal therapy with minimal toxic side effects. Thus, our work presents a promising strategy for significantly improving the precision and specificity of cancer imaging and therapy.
-
activatable two photon fluorescence Nanoprobe for bioimaging of glutathione in living cells and tissues
Analytical Chemistry, 2014Co-Authors: Hongmin Meng, Xiaobing Zhang, Zhen Jin, Chan Yang, Weihong TanAbstract:Glutathione (GSH) serves vital cellular biological functions, and its abnormal levels are associated with many diseases. To better understand its physiological and pathological functions, efficient methods for monitoring of GSH in living systems are desired. Although quite a few small molecule-based and nanomaterial-based one photon fluorescence probes have been reported for GSH, two-photon (TP) probes, especially Nanoprobes with good membrane permeability, are more favorable for bioimaging applications, since TP fluorescence imaging can provide improved spatial localization and increased imaging depth. In this work, we for the first time reported a “turn-on” TP fluorescence Nanoprobe for efficient detection of GSH in aqueous solutions and TP excited fluorescence imaging of GSH in living cells and tissues. The Nanoprobe consists of two-photon mesoporous silica nanoparticles (TP-MSNs) with a large TP excitation action cross-section (Φδ) value of 103 GM and MnO2 nanosheets, which show intense and broad opti...
Tuan Vo-dinh - One of the best experts on this subject based on the ideXlab platform.
-
Plasmonic Nanoprobes for intracellular sensing and imaging
Analytical and bioanalytical chemistry, 2013Co-Authors: Hsiangkuo Yuan, Janna K. Register, Hsin-neng Wang, Andrew M. Fales, Yang Liu, Tuan Vo-dinhAbstract:Recent advances in integrating nanotechnology and optical microscopy offer great potential in intracellular applications with improved molecular information and higher resolution. Continuous efforts in designing nanoparticles with strong and tunable plasmon resonance have led to new developments in biosensing and bioimaging, using surface-enhanced Raman scattering and two-photon photoluminescence. We provide an overview of the Nanoprobe design updates, such as controlling the nanoparticle shape for optimal plasmon peak position; optical sensing and imaging strategies for intracellular nanoparticle detection; and addressing practical challenges in cellular applications of Nanoprobes, including the use of targeting agents and control of nanoparticle aggregation.
-
Design and Fabrication of Fiber-Optic Nanoprobes for Optical Sensing.
Nanoscale research letters, 2010Co-Authors: Yan Zhang, Anuj Dhawan, Tuan Vo-dinhAbstract:This paper describes the design and fabrication of fiber-optic Nanoprobes developed for optical detection in single living cells. It is critical to fabricate probes with well-controlled nanoapertures for optimized spatial resolution and optical transmission. The detection sensitivity of fiber-optic Nanoprobe depends mainly on the extremely small excitation volume that is determined by the aperture sizes and penetration depths. We investigate the angle dependence of the aperture in shadow evaporation of the metal coating onto the tip wall. It was found that nanoaperture diameters of approximately 50 nm can be achieved using a 25° tilt angle. On the other hand, the aperture size is sensitive to the subtle change of the metal evaporation angle and could be blocked by irregular metal grains. Through focused ion beam (FIB) milling, optical Nanoprobes with well-defined aperture size as small as 200 nm can be obtained. Finally, we illustrate the use of the Nanoprobes by detecting a fluorescent species, benzo[a]pyrene tetrol (BPT), in single living cells. A quantitative estimation of the numbers of BPT molecules detected using fiber-optic Nanoprobes for BPT solutions shows that the limit of detection was approximately 100 molecules.
-
Nanobiosensing Using Plasmonic Nanoprobes
IEEE journal of selected topics in quantum electronics : a publication of the IEEE Lasers and Electro-optics Society, 2008Co-Authors: Tuan Vo-dinhAbstract:This paper provides an overview of the development and applications of plasmonics-active Nanoprobes in biomedical diagnostics. Specific examples of detection techniques using surface-enhanced Raman scattering are presented to illustrate the usefulness and potential of the plasmonics Nanoprobes for gene detection and nanobiosensing. The detection of specific target deoxyribonucleic acids sequences using a novel "molecular sentinel" Nanoprobe method is presented and discussed in detail.
-
Development of Nanosensors and Bioprobes
Journal of Nanoparticle Research, 2000Co-Authors: Tuan Vo-dinh, Guy D. Griffin, Jean Pierre Alarie, Brian Cullum, Bobby Sumpter, Donald NoidAbstract:We describe the development and application of nanosensors having bioreceptor probes for bioanalysis. The Nanoprobes were fabricated with optical fibers pulled down to tips having distal end sizes of approximately 30–60 nm. The use of two different types of receptors was investigated. Fiberoptic Nanoprobes were covalently bound either with bioreceptors, such as antibodies, or with other receptors, such as cyclodextrins that are selective for the size and chemical structure of the analyte molecules. Theoretical calculations were performed to model the binding of beta-cyclodextrin with pyrene and 5,6-benzoquinoline, and to illustrate the possibility of comparing experimental data with theoretical data. The antibody-based Nanoprobe was used for in situ measurements of benzopyrene tetrol in single cells. The performance of the nanosensor is illustrated by intracellular measurements performed on a rat liver epithelial cell line (Clone 9) used as the model cell system. The usefulness and potential of these nanotechnology-based biosensors in biological research and applications are discussed.
-
Antibody-based Nanoprobe for measurement of a fluorescent analyte in a single cell.
Nature biotechnology, 2000Co-Authors: Tuan Vo-dinh, Jean Pierre Alarie, Brian M. Cullum, Guy D. GriffinAbstract:We report here the application of an antibody-based Nanoprobe for in situ measurements of a single cell. The Nanoprobe employs antibody-based receptors targeted to a fluorescent analyte, benzopyrene tetrol (BPT), a metabolite of the carcinogen benzo[a]pyrene (BaP) and of the BaP–DNA adduct. Detection of BPT is of great biomedical interest, since this species can serve as a biomarker for monitoring DNA damage due to BaP exposure and for possible precancer diagnosis. The measurements were performed on the rat liver epithelial clone 9 cell line, which was used as the model cell system. Before making measurements, the cells were treated with BPT. Nanoprobes were inserted into individual cells, incubated 5 min to allow antigen–antibody binding, and then removed for fluorescence detection. We determined a concentration of 9.6 ± 0.2 × 10−11 M for BPT in the individual cells investigated. The results demonstrate the possibility of in situ measurements inside a single cell using an antibody-based Nanoprobe.
