The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Markita P. Landry - One of the best experts on this subject based on the ideXlab platform.
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high throughput evolution of near infrared serotonin Nanosensors
bioRxiv, 2019Co-Authors: Sanghwa Jeong, Darwin Yang, Abraham G Beyene, Anneliese M M Gest, Markita P. LandryAbstract:ABSTRACT Release and reuptake of neuromodulator serotonin, 5-HT, is central to mood regulation and neuropsychiatric disorders, whereby imaging serotonin is of fundamental importance to study the brain’s serotonin signaling system. We introduce a reversible near-infrared Nanosensor for serotonin (nIRHT), for which synthetic molecular recognition toward serotonin is systematically evolved from ssDNA-carbon nanotube constructs generated from large libraries of 6.9 × 1010 unique ssDNA sequences. nIRHT produces a ∼200% fluorescence enhancement upon exposure to serotonin with a Kd = 6.3 µM affinity. nIRHT shows selective responsivity towards serotonin over serotonin analogs, metabolites, and receptor-targeting drugs, and a 5-fold increased affinity for serotonin over dopamine. Further, nIRHT can be introduced into the brain extracellular space in acute slice, and can be used to image exogenous serotonin reversibly. Our results suggest evolution of Nanosensors could be generically implemented to rapidly develop other neuromodulator probes, and that these probes can image neuromodulator dynamics at spatiotemporal scales compatible with endogenous neuromodulation.
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Electrostatic Assemblies of Single-Walled Carbon Nanotubes and Sequence-Tunable Peptoid Polymers Detect a Lectin Protein and Its Target Sugars
2019Co-Authors: Linda Chio, Ian R Mcfarlane, Jackson Travis Del Bonis-o’donnell, Mark A. Kline, Jae Hong Kim, Ronald N. Zuckermann, Markita P. LandryAbstract:A primary limitation to real-time imaging of metabolites and proteins has been the selective detection of biomolecules that have no naturally occurring or stable molecular recognition counterparts. We present developments in the design of synthetic near-infrared fluorescent Nanosensors based on the fluorescence modulation of single-walled carbon nanotubes (SWNTs) with select sequences of surface-adsorbed N-substituted glycine peptoid polymers. We assess the stability of the peptoid-SWNT Nanosensor candidates under variable ionic strengths, protease exposure, and cell culture media conditions and find that the stability of peptoid-SWNTs depends on the composition and length of the peptoid polymer. From our library, we identify a peptoid-SWNT assembly that can detect lectin protein wheat germ agglutinin (WGA) with a sensitivity comparable to the concentration of serum proteins. To demonstrate the retention of Nanosensor-bound protein activity, we show that WGA on the Nanosensor produces an additional fluorescent signal modulation upon exposure to the lectin’s target sugars, suggesting the lectin protein remains active and selectively binds its target sugars through ternary molecular recognition interactions relayed to the Nanosensor. Our results inform design considerations for developing synthetic molecular recognition elements by assembling peptoid polymers on SWNTs and also demonstrate these assemblies can serve as optical Nanosensors for lectin proteins and their target sugars. Together, these data suggest certain peptoid sequences can be assembled with SWNTs to serve as versatile optical probes to detect proteins and their molecular substrates
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Chemometric Approaches for Developing Infrared Nanosensors To Image Anthracyclines.
Biochemistry, 2018Co-Authors: Jackson Travis Del Bonis-o'donnell, Rebecca L. Pinals, Sanghwa Jeong, Ami Thakrar, Russell D. Wolfinger, Markita P. LandryAbstract:Generation, identification, and validation of optical probes to image molecular targets in a biological milieu remain a challenge. Synthetic molecular recognition approaches leveraging the intrinsic near-infrared fluorescence of single-walled carbon nanotubes are promising for long-term biochemical imaging in tissues. However, generation of Nanosensors for selective imaging of molecular targets requires a heuristic approach. Here, we present a chemometric platform for rapidly screening libraries of candidate single-walled carbon nanotube Nanosensors against biochemical analytes to quantify the fluorescence response to small molecules, including vitamins, neurotransmitters, and chemotherapeutics. We further show this method can be applied to identify biochemical analytes that selectively modulate the intrinsic near-infrared fluorescence of candidate Nanosensors. Chemometric analysis thus enables identification of Nanosensor–analyte “hits” and also Nanosensor fluorescence signaling modalities such as wavele...
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CHEMOMETRIC APPROACHES FOR DEVELOPING INFRARED NanosensorS TO IMAGE ANTHRACYCLINES
2018Co-Authors: Jackson Travis Del Bonis-o'donnell, Rebecca L. Pinals, Sanghwa Jeong, Ami Thakrar, Russell D. Wolfinger, Markita P. LandryAbstract:Generation, identification, and validation of optical probes to image molecular targets in a biological milieu remains a challenge. Synthetic molecular recognition approaches leveraging the intrinsic near-infrared fluorescence of single-walled carbon nanotubes is a promising approach for chronic biochemical imaging in tissues. However, generation of Nanosensors for selective imaging of molecular targets requires a heuristic approach. Here, we present a chemometric platform for rapidly screening libraries of candidate single-walled carbon nanotube Nanosensors against biochemical analytes to quantify fluorescence response to small molecules including vitamins, neurotransmitters, and chemotherapeutics. We further show this approach can be leveraged to identify biochemical analytes that selectively modulate the intrinsic near-infrared fluorescence of candidate Nanosensors. Chemometric analysis thus enables identification of Nanosensor-analyte hits and also Nanosensor fluorescence signaling modalities such as wavelength-shifts that are optimal for translation to biological imaging. Through this approach, we identify and characterize a Nanosensor for the chemotherapeutic anthracycline doxorubicin, which provides an up to 17 nm fluorescence red-shift and exhibits an 8 uM limit of detection, compatible with peak circulatory concentrations of doxorubicin common in therapeutic administration. We demonstrate selectivity of this Nanosensor over dacarbazine, a chemotherapeutic commonly co-injected with DOX. Lastly, we demonstrate Nanosensor tissue compatibility for imaging of doxorubicin in muscle tissue by incorporating Nanosensors into the mouse hindlimb and measuring Nanosensor response to exogenous DOX administration. Our results motivate chemometric approaches to Nanosensor discovery for chronic imaging of drug partitioning into tissues and towards real-time monitoring of drug accumulation.
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dual near infrared two photon microscopy for deep tissue dopamine Nanosensor imaging
Advanced Functional Materials, 2017Co-Authors: Jackson Travis Del Bonisodonnell, Markita P. Landry, Abraham G Beyene, Ian R Mcfarlane, Ralph H Page, Eric G TindallAbstract:A key limitation for achieving deep imaging in biological structures lies in photon absorption and scattering leading to attenuation of fluorescence. In particular, neurotransmitter imaging is challenging in the biologically relevant context of the intact brain for which photons must traverse the cranium, skin, and bone. Thus, fluorescence imaging is limited to the surface cortical layers of the brain, only achievable with craniotomy. Herein, this study describes optimal excitation and emission wavelengths for through-cranium imaging, and demonstrates that near-infrared emissive Nanosensors can be photoexcited using a two-photon 1560 nm excitation source. Dopamine-sensitive Nanosensors can undergo two-photon excitation, and provide chirality-dependent responses selective for dopamine with fluorescent turn-on responses varying between 20% and 350%. The two-photon absorption cross-section and quantum yield of dopamine Nanosensors are further calculated, and a two-photon power law relationship for the Nanosensor excitation process is confirmed. Finally, the improved image quality of the Nanosensors embedded 2-mm-deep into a brain-mimetic tissue phantom is shown, whereby one-photon excitation yields 42% scattering, in contrast to 4% scattering when the same object is imaged under two-photon excitation. The approach overcomes traditional limitations in deep-tissue fluorescence microscopy, and can enable neurotransmitter imaging in the biologically relevant milieu of the intact and living brain.
Hui Feng - One of the best experts on this subject based on the ideXlab platform.
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a fluorescent Nanosensor based on graphene quantum dots aptamer probe and graphene oxide platform for detection of lead ii ion
Biosensors and Bioelectronics, 2015Co-Authors: Zhaosheng Qian, Xiao Yue Shan, Lu Jing Chai, Jianrong Chen, Hui FengAbstract:The sensitive detection of heavy metal ions in the organism and aquatic ecosystem using Nanosensors based on environment friendly and biocompatible materials still remains a challenge. A fluorescent turn-on Nanosensor for lead (II) detection based on biocompatible graphene quantum dots and graphene oxide by employment of Pb(2+)-induced G-quadruplex formation was reported. Graphene quantum dots with high quantum yield, good biocompatibility were prepared and served as the fluorophore of Pb(2+) probe. Fluorescence turn-off of graphene quantum dots is easily achieved through efficient photoinduced electron transfer between graphene quantum dots and graphene oxide, and subsequent fluorescence turn-on process is due to the formation of G-quadraplex aptamer-Pb(2+) complex triggered by the addition of Pb(2+). This Nanosensor can distinguish Pb(2+) ion from other ions with high sensitivity and good reproducibility. The detection method based on this Nanosensor possesses a fast response time of one minute, a broad linear span of up to 400.0 nM and ultralow detection limit of 0.6 nM.
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dna Nanosensor based on biocompatible graphene quantum dots and carbon nanotubes
Biosensors and Bioelectronics, 2014Co-Authors: Zhaosheng Qian, Xiao Yue Shan, Lu Jing Chai, Jianrong Chen, Juan Juan, Hui FengAbstract:An ultrasensitive Nanosensor based on fluorescence resonance energy transfer (FRET) between biocompatible graphene quantum dots and carbon nanotubes for DNA detection was reported. We take advantage of good biocompatibility and strong fluorescence of graphene quantum dots, base pairing specificity of DNA and unique fluorescence resonance energy transfer between graphene quantum dots and carbon nanotubes to achieve the analysis of low concentrations of DNA. Graphene quantum dots with high quantum yield up to 0.20 were prepared and served as the fluorophore of DNA probe. FRET process between graphene quantum dots-labeled probe and oxidized carbon nanotubes is easily achieved due to their efficient self-assembly through specific π-π interaction. This Nanosensor can distinguish complementary and mismatched nucleic acid sequences with high sensitivity and good reproducibility. The detection method based on this Nanosensor possesses a broad linear span of up to 133.0 nM and ultralow detection limit of 0.4 nM. The constructed Nanosensor is expected to be highly biocompatible because of all its components with excellent biocompatibility.
Heng Zhang - One of the best experts on this subject based on the ideXlab platform.
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carbon dot based dual emission silica nanoparticles as a ratiometric fluorescent probe for vanadium v detection in mineral water samples
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2018Co-Authors: Heng Zhang, Huanhuan Fan, Xiuming Jiang, Wenjie Zhao, Guo Qiang XiangAbstract:Herein, we propose a simple and effective strategy for designing a ratiometric fluorescent Nanosensor. We designed and developed a carbon dots (CDs) based dual-emission Nanosensor for vanadium(V) by coating the surface of dye-doped silica nanoparticles with CDs. The fluorescence of dual-emission silica nanoparticles was quenched in acetic acid through potassium bromate (KBrO3) oxidation. V(V) could catalyze KBrO3 oxidation reaction process, resulting in the ratiometric fluorescence quenching of dual-emission silica nanoparticles. We investigated several important parameters affecting the performance of the Nanosensor. Under the optimized conditions, the detection limit of this Nanosensor reached 1.1ngmL-1 and the linear range from 10 to 800ngmL-1. Furthermore, we found that the sensor was suitable for determination of V(V) in different mineral water samples with satisfactory results.
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a dual mode Nanosensor based on carbon quantum dots and gold nanoparticles for discriminative detection of glutathione in human plasma
Biosensors and Bioelectronics, 2014Co-Authors: Yupeng Shi, Heng Zhang, Zhaomin Zhang, Yi Pan, Mengsu YangAbstract:Glutathione (GSH) plays key roles in biological systems and serves many cellular functions. Since biothiols all incorporate thiol, carboxylic and amino groups, discriminative detection of GSH over cysteine (Cys) and homocysteine (Hcy) is still challenging. We herein report a dual-mode Nanosensor with both colorimetric and fluorometric readout based on carbon quantum dots and gold nanoparticles for discriminative detection of GSH over Cys/Hcy. The proposed sensing system consists of AuNPs and fluorescent carbon quantum dots (CQDs), where CQDs function as fluorometric reporter, and AuNPs serve a dual function as colorimetric reporter and fluorescence quencher. The mechanism of the Nanosensor is based on two distance-dependent phenomenons, color change of AuNPs and FRET. Through controlling the surface properties of as-prepared nanoparticles, the addition of CQDs into AuNPs colloid solution might induce the aggregation of AuNPs and CQDs, leading to AuNPs color changing from red to blue and CQDs fluorescence quench. However, the presence of GSH can protect AuNPs from being aggregated and enlarge the inter-particle distance, which subsequently produces color change and fluorescent signal recovery. The Nanosensor described in this report reflects on its simplicity and flexibility, where no further surface functionalization is required for the as-prepared nanoparticles, leading to less laborious and more cost-effective synthesis. The proposed dual-mode Nanosensor demonstrated highly selectivity toward GSH, and allows the detection of GSH as low as 50 nM. More importantly, the Nanosensor could not only function in aqueous solution for GSH detection with high sensitivity but also exhibit sensitive responses toward GSH in complicated biological environments, demonstrating its potential in bioanalysis and biodection, which might be significant in disease diagnosis in the future.
Guo Qiang Xiang - One of the best experts on this subject based on the ideXlab platform.
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carbon dot based dual emission silica nanoparticles as a ratiometric fluorescent probe for vanadium v detection in mineral water samples
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2018Co-Authors: Heng Zhang, Huanhuan Fan, Xiuming Jiang, Wenjie Zhao, Guo Qiang XiangAbstract:Herein, we propose a simple and effective strategy for designing a ratiometric fluorescent Nanosensor. We designed and developed a carbon dots (CDs) based dual-emission Nanosensor for vanadium(V) by coating the surface of dye-doped silica nanoparticles with CDs. The fluorescence of dual-emission silica nanoparticles was quenched in acetic acid through potassium bromate (KBrO3) oxidation. V(V) could catalyze KBrO3 oxidation reaction process, resulting in the ratiometric fluorescence quenching of dual-emission silica nanoparticles. We investigated several important parameters affecting the performance of the Nanosensor. Under the optimized conditions, the detection limit of this Nanosensor reached 1.1ngmL-1 and the linear range from 10 to 800ngmL-1. Furthermore, we found that the sensor was suitable for determination of V(V) in different mineral water samples with satisfactory results.
Dihua Shangguan - One of the best experts on this subject based on the ideXlab platform.
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carbon dots based dual emission silica nanoparticles as a ratiometric Nanosensor for cu2
Analytical Chemistry, 2014Co-Authors: Xiangjun Liu, Nan Zhang, Tao Bing, Dihua ShangguanAbstract:A simple and effective strategy for designing ratiometric fluorescent Nanosensor has been described in this work. A carbon dots (CDs) based dual-emission Nanosensor for Cu2+ detection was prepared by coating CDs on the surface of Rhodamine B-doped silica nanoparticles. The fluorescent CDs were synthesized using N-(β-aminoethyl)-γ-aminopropyl methyldimethoxysilane (AEAPMS) as the main raw material, so that the residual ethylenediamine groups and methoxysilane groups on the surface of CDs can serve as the Cu2+ recognition sites and the silylation reaction groups. The obtained Nanosensor showed characteristic fluorescence emissions of Rhodamine B (red) and CDs (blue) under a single excitation wavelength. Upon binding to Cu2+, only the fluorescence of CDs was quenched, resulting in the ratiometric fluorescence response of the dual-emission silica nanoparticles. This ratiometric Nanosensor exhibited good selectivity to Cu2+ over other substances, such as metal ions, amino acids, proteins, and vitamin C. The ra...
