The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform

Kevin Burgess - One of the best experts on this subject based on the ideXlab platform.

  • syntheses photophysical properties and application of through Bond Energy transfer cassettes for biotechnology
    Chemistry: A European Journal, 2006
    Co-Authors: Guansheng Jiao, Lars H Thoresen, Robin M Hochstrasser, Michael R Topp, Wade C Haaland, Michael L Metzker, Kevin Burgess
    Abstract:

    We have designed fluores- cent "through-Bond Energy-transfer cassettes" that can harvest Energy of a relatively short wavelength (e.g., 490 nm), and emit it at appreciably longer wavelengths without significant loss of intensity. Probes of this type could be particularly useful in biotech- nology for multiplexing experiments in which several different outputs are to be observed from a single excitation source. Cassettes 1-4 were designed, prepared, and studied as model systems to achieve this end. They were synthe- sized through convergent routes that feature coupling of specially prepared fluorescein- and rhodamine-derived fragments. The four cassettes were shown to emit strongly, with highly effi- cient Energy transfer. Their emission maxima cover a broad range of wave- lengths (broader than the four dye cas- settes currently used for most high- throughput DNA sequencing), and they exhibit faster Energy-transfer rates than a similar through-space Energy- transfer cassette. Specifically, Energy- transfer rates in these cassettes is around 6-7 ps, in contrast to a similar through-space Energy-transfer system shown to have a decay time of around 35 ps. Moreover, the cassettes are con- siderably more stable to photobleach- ing than fluorescein, even though they each contain fluorescein-derived do- A This was confirmed by bulkfluo- A measurements, and in single- molecule-detection studies. Modifica- tion of a commercial automated DNA- sequencing apparatus to detect the emissions of these four Energy-transfer cassettes enabled single-color dye- primer sequencing.

  • water soluble through Bond Energy transfer cassettes for intracellular imaging
    Journal of the American Chemical Society, 2006
    Co-Authors: Rakeshwar Bandichhor, Anca D Petrescu, Aude Vespa, Ann B Kier, Friedhelm Schroeder, Kevin Burgess
    Abstract:

    A special, water-soluble, fluorescent probe 1 was designed. This consisted of a fluorescein-based component to harvest irradiation at 488 nm and a rhodamine-based part designed to emit it at a significantly longer wavelength. This cassette was used to label an illustrative protein called ACBP. Evidence was accumulated to support the assertion that ACBP-1 bound its native ligand with a binding constant similar to that of the unlabeled protein, and retained its secondary structure (CD). ACBP-1 was imported into cells using the Chariot peptide. Confocal images proved that some ACBP-1 localized into the nucleus (as expected) and, most significantly, it could be visualized more effectively by irradiating at the donor (fluorescein-like) part of the cassette, than the acceptor (rhodamine-like) part. Overall, this study demonstrates that cassettes of this kind can label a protein without significantly perturbing its function or secondary structure and they can be visualized effectively via irradiation of the dono...

  • correlations of structure and rates of Energy transfer for through Bond Energy transfer cassettes
    Journal of Physical Chemistry A, 2006
    Co-Authors: Juan C Castro, Kevin Burgess, Aurore Loudet, J G S Jiao, Robin M Hochstrasser, Michael R Topp
    Abstract:

    Fluorescent DNA-labeling cassettes are designed to have a common absorbing chromophore matched to a single exciting laser wavelength, but up to four different emitters. Experiments reported here have examined the Energy-transfer rates and fluorescence polarization characteristics for two different types of cassette, involving three distinct relative orientations of the donor and acceptor transition moments and the axis of the rigid linker. Energy-transfer times range from <200 fs to ∼20 ps, the fastest transfer times occurring when the transition moments of the donor and acceptor species are aligned parallel to the linker axis. Experimental evidence is presented that supports a through-Bond Energy-transfer mechanism, in contrast with a commercial DNA-labeling agent, which exhibits much slower transfer times controlled by FRET. These rigid cassettes also exhibit polarized fluorescence from the acceptor species, so that this particular type of DNA-labeling probe has some of the advantages of single-molecule...

  • fluorescent through Bond Energy transfer cassettes for labeling multiple biological molecules in one experiment
    Journal of the American Chemical Society, 2003
    Co-Authors: Guansheng Jiao, Lars H Thoresen, Kevin Burgess
    Abstract:

    Through-Bond Energy transfer cassettes based on a fluorescein donor component electronically conjugated to rhodamine-like acceptors have been designed and synthesized. They absorb strongly at 488 nm (Ar-laser emission) and efficiently transfer the Energy to the acceptor component that emits strongly. Further, the cassettes are more stable to photobleaching than fluorescein, making them potentially more suitable for single-molecule detection methods than fluorescein itself. These studies form the basis for improved detection of chain-terminated DNA in high-throughput sequencing and other applications in biotechnology.

Xiaobing Zhang - One of the best experts on this subject based on the ideXlab platform.

  • through Bond Energy transfer based ratiometric two photon probe for fluorescent imaging of pd2 ions in living cells and tissues
    Analytical Chemistry, 2015
    Co-Authors: Liyi Zhou, Qianqian Wang, Xiaobing Zhang
    Abstract:

    Palladium can cause severe skin and eye irritation once it enters the human body. Ratiometric two-photon fluorescent probes can both eliminate interference from environmental factors and realize deep-tissue imaging with improved spatial localization. To quantitatively track Pd2+ in biosystems, we report here a colorimetric and two-photon ratiometric fluorescent probe, termed Np–Rh–Pd, which consists of a two-photon fluorophore (naphthalene derivative with a D-π-A structure) and a rhodamine B dye. The two fluorophores are directly linked to form a two-photon ratiometric fluorescent probe for Pd2+ based on a through-Bond Energy transfer (TBET) strategy. It exhibits highly efficient Energy transfer (90%) with two well-resolved emission peaks (wavelength difference of 100 nm), which could efficiently diminish the cross talk between channels and is especially favorable for ratiometric bioimaging applications. A signal-to-background ratio of 31.2 was observed for the probe, which affords a high sensitivity for ...

  • through Bond Energy transfer a convenient and universal strategy toward efficient ratiometric fluorescent probe for bioimaging applications
    Analytical Chemistry, 2012
    Co-Authors: Yijun Gong, Xiaobing Zhang, Cuicui Zhang, Ting Fu, Guoli Shen, Ruqin Yu
    Abstract:

    Fluorescence resonance Energy transfer (FRET) strategy has been widely applied in designing ratiometric probes for bioimaging applications. Unfortunately, for FRET systems, sufficiently large spectral overlap is necessary between the donor emission and the acceptor absorption, which would limit the resolution of double-channel images. The through-Bond Energy transfer (TBET) system does not need spectral overlap between donor and acceptor and could afford large wavelength difference between the two emissions with improved imaging resolution and higher Energy transfer efficiency than that of the classical FRET system. It seems to be more favorable for designing ratiometric probes for bioimaging applications. In this paper, we have designed and synthesized a coumarin–rhodamine (CR) TBET system and demonstrated that TBET is a convenient strategy to design an efficient ratiometric fluorescent bioimaging probe for metal ions. Such TBET strategy is also universal, since no spectral overlap between the donor and ...

Ben Zhong Tang - One of the best experts on this subject based on the ideXlab platform.

  • design of multi functional aiegens tunable emission circularly polarized luminescence and self assembly by dark through Bond Energy transfer
    Journal of Materials Chemistry C, 2018
    Co-Authors: Haitao Feng, Xinggui Gu, Ben Zhong Tang, Yansong Zheng
    Abstract:

    A pair of chiral R/S-TPE-BINOL derivatives with dark resonance Energy transfer was facilely synthesized by coupling of a tetraphenylethylene (TPE) derivative, BODIPY dye and R/S-1,1′-bi-2-binaphthol (BINOL), where TPE not only was selected as a dark Energy donor, but also can endow the target molecules with aggregation-induced emission (AIE) characteristics; BODIPY served as an Energy acceptor; BINOL, one of the most popular axially chiral compounds, was employed as a chiral source. Due to the chiral feature of R/S-TPE-BINOL, obvious CD and CPL signals were observed in the solution and aggregated states. Generally, for organic dyes, high dissymmetric factor (gem) values are often accompanied by low emission efficiencies. To improve emission efficiency, an effective strategy of dark through-Bond Energy transfer was adopted. This method makes it possible to avoid fluorescence leakage originating from donor emission. The Energy of TPE can be completely transferred to the BODIPY unit before non-radiative relaxation with an Energy transfer efficiency of up to 99% and a high quantum yield of 91%. Remarkably, these enantiomers could self-assemble into bowl-like hollow microspheres in a mixed solvent of THF/water to give a stable fluorescent suspension with tunable emission from the green to yellow region. Moreover, TPE-BOD was selected as the fluorescent probe for specific staining of lipid droplets in living cells.

  • aiegens for dark through Bond Energy transfer design synthesis theoretical study and application in ratiometric hg2 sensing
    Chemical Science, 2017
    Co-Authors: Yuncong Chen, Weijie Zhang, Ryan T K Kwok, Yubing Hu, Xinggui Gu, Zikai He, Zheng Zhao, Xiaoyan Zheng, Bin Chen, Ben Zhong Tang
    Abstract:

    A novel dark through-Bond Energy transfer (DTBET) strategy is proposed and applied as the design strategy to develop ratiometric Hg2+ sensors with high performance. Tetraphenylethene (TPE) derivatives with aggregation-induced emission (AIE) characteristics are selected as dark donors to eliminate emission leakage from the donors. The TBET mechanism has been adopted since it experiences less influence from spectral overlapping than Forster resonance Energy transfer (FRET), making it more flexible for developing cassettes with large pseudo-Stokes shifts. In this work, Energy transfer from the TPE derivatives (dark donor) to a rhodamine moiety (acceptor) was illustrated through photophysical spectroscopic studies and the Energy transfer efficiency (ETE) was found to be up to 99%. In the solution state, no emission from the donors was observed and large pseudo-Stokes shifts were achieved (>280 nm), which are beneficial for biological imaging. Theoretical calculations were performed to gain a deeper mechanistic insight into the DTBET process and the structure–property relationship of the DTBET cassettes. Ratiometric Hg2+ sensors were rationally constructed based on the DTBET mechanism by taking advantage of the intense emission of TPE aggregates. The Hg2+ sensors exhibited well resolved emission peaks. >6000-fold ratiometric fluorescent enhancement is also achieved and the detection limit was found to be as low as 0.3 ppb. This newly proposed DTBET mechanism could be used to develop novel ratiometric sensors for various analytes and AIEgens with DTBET characteristics will have great potential in various areas including light harvesting materials, environmental science, chemical sensing, biological imaging and diagnostics.

Baoxiang Zhao - One of the best experts on this subject based on the ideXlab platform.

  • through Bond Energy transfer based ratiometric fluorescent probe for the imaging of hocl in living cells
    Sensors and Actuators B-chemical, 2017
    Co-Authors: Shili Shen, Junya Ning, Xiaofan Zhang, Junying Miao, Baoxiang Zhao
    Abstract:

    Abstract A ratiometric fluorescent probe ( NR ) for HOCl based on a new naphthalimide-rhodamine platform involving through-Bond Energy transfer (TBET) process is presented. Rhodamine B thiohydrazide and naphthalimide derivative were linked to form a structure of monothio-bishydrazide. Free NR only emitted the fluorescence of naphthalimide. The treatment of NR with HOCl converted the monothio-bishydrazide into 1,2,4-oxadiazole. As a result, naphthalimide donor and rhodamine acceptor were connected with electronically conjugated Bonds, and the spiro ring of rhodamine was opened. Hence, a typical TBET process took place, resulting in the increase of rhodamine emission at 582 nm as well as the decrease of naphthalimide emission at 532 nm. I 582 /I 532 ratios showed desirable HOCl-dependent performance and responded linearly to minor changes of HOCl concentration (0–5 μM). The detection limit was determined to be 14.5 nM. NR exhibited high selectivity, rapid response and low cytotoxicity. Moreover, NR has been employed for the imaging of artificially loaded HOCl and endogenously produced HOCl with satisfying results. Therefore, NR may act as a practical molecular tool for monitoring HOCl fluctuations in biological systems.

  • a ratiometric fluorescent probe based on a through Bond Energy transfer tbet system for imaging hocl in living cells
    Chemistry: A European Journal, 2015
    Co-Authors: Yanru Zhang, Junying Miao, Ning Meng, Baoxiang Zhao
    Abstract:

    A simple ratiometric probe (Naph-Rh) has been designed and synthesized based on a through-Bond Energy transfer (TBET) system for sensing HOCl. In this probe, rhodamine thiohydrazide and naphthalene formyl were connected by simple synthesis methods to construct a structure of monothio-bishydrazide. Free probe Naph-Rh showed only the emission of naphthalene. When probe Naph-Rh reacted with HOCl, monothio-bishydrazide could be converted into 1,2,4-oxadiazole, which not only ensured that the donor and the acceptor were connected with electronically conjugated Bonds, but also resulted in the spiro-ring opening and the emission of rhodamine. Therefore, a typical TBET process took place. The probe possessed high-Energy transfer efficiency and large pseudo-Stokes shifts. As the first TBET probe for HOCl, Naph-Rh showed excellent selectivity and sensitivity toward HOCl over other reactive oxygen species (ROS)/reactive nitrogen species (RNS), and could respond fast to a low concentration of HOCl in the real sample. In addition, the probe was suitable for imaging HOCl in living cells due to its real-time response, excellent resolution, and reduced cytotoxicity.

Michael R Topp - One of the best experts on this subject based on the ideXlab platform.

  • syntheses photophysical properties and application of through Bond Energy transfer cassettes for biotechnology
    Chemistry: A European Journal, 2006
    Co-Authors: Guansheng Jiao, Lars H Thoresen, Robin M Hochstrasser, Michael R Topp, Wade C Haaland, Michael L Metzker, Kevin Burgess
    Abstract:

    We have designed fluores- cent "through-Bond Energy-transfer cassettes" that can harvest Energy of a relatively short wavelength (e.g., 490 nm), and emit it at appreciably longer wavelengths without significant loss of intensity. Probes of this type could be particularly useful in biotech- nology for multiplexing experiments in which several different outputs are to be observed from a single excitation source. Cassettes 1-4 were designed, prepared, and studied as model systems to achieve this end. They were synthe- sized through convergent routes that feature coupling of specially prepared fluorescein- and rhodamine-derived fragments. The four cassettes were shown to emit strongly, with highly effi- cient Energy transfer. Their emission maxima cover a broad range of wave- lengths (broader than the four dye cas- settes currently used for most high- throughput DNA sequencing), and they exhibit faster Energy-transfer rates than a similar through-space Energy- transfer cassette. Specifically, Energy- transfer rates in these cassettes is around 6-7 ps, in contrast to a similar through-space Energy-transfer system shown to have a decay time of around 35 ps. Moreover, the cassettes are con- siderably more stable to photobleach- ing than fluorescein, even though they each contain fluorescein-derived do- A This was confirmed by bulkfluo- A measurements, and in single- molecule-detection studies. Modifica- tion of a commercial automated DNA- sequencing apparatus to detect the emissions of these four Energy-transfer cassettes enabled single-color dye- primer sequencing.

  • correlations of structure and rates of Energy transfer for through Bond Energy transfer cassettes
    Journal of Physical Chemistry A, 2006
    Co-Authors: Juan C Castro, Kevin Burgess, Aurore Loudet, J G S Jiao, Robin M Hochstrasser, Michael R Topp
    Abstract:

    Fluorescent DNA-labeling cassettes are designed to have a common absorbing chromophore matched to a single exciting laser wavelength, but up to four different emitters. Experiments reported here have examined the Energy-transfer rates and fluorescence polarization characteristics for two different types of cassette, involving three distinct relative orientations of the donor and acceptor transition moments and the axis of the rigid linker. Energy-transfer times range from <200 fs to ∼20 ps, the fastest transfer times occurring when the transition moments of the donor and acceptor species are aligned parallel to the linker axis. Experimental evidence is presented that supports a through-Bond Energy-transfer mechanism, in contrast with a commercial DNA-labeling agent, which exhibits much slower transfer times controlled by FRET. These rigid cassettes also exhibit polarized fluorescence from the acceptor species, so that this particular type of DNA-labeling probe has some of the advantages of single-molecule...