45 results match your criteria reported nanodisk

Optical Bound States in Continuum in MoS-Based Metasurface for Directional Light Emission.

Nano Lett 2021 Jan 15;21(2):967-972. Epub 2021 Jan 15.

Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China.

High quality factor (-factor) and strong field localization in nanostructures is a newly emerged direction in nanophotonics. The bound states in the continuum (BIC) have been investigated in nanoparticles with infinite -factor. We report BIC in molybdenum disulfide (MoS) based Mie nanoresonator suspended in air. Read More

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January 2021

Serum-Based Diagnosis of Pediatric Tuberculosis by Assay of Mycobacterium tuberculosis Factors: a Retrospective Cohort Study.

J Clin Microbiol 2021 01 21;59(2). Epub 2021 Jan 21.

Department of Biochemistry and Molecular Biology Center for Cellular and Molecular Diagnosis, School of Medicine, Tulane University, New Orleans, Louisiana, USA

Diagnosis of pediatric tuberculosis (TB) is often complicated by its nonspecific symptoms, paucibacillary nature, and the need for invasive specimen collection techniques. However, a recently reported assay that detects virulence factors in serum can diagnose various TB manifestations, including paucibacillary TB cases, in adults with good sensitivity and specificity. The current study examined the ability of this biomarker assay to diagnose pediatric TB using archived cryopreserved serum samples drawn from children ≤18 years of age who were screened for suspected TB as part of a prospective population-based active surveillance study. Read More

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January 2021

Nitrogen Bubbles at Pt Nanoelectrodes in a Nonaqueous Medium: Oscillating Behavior and Geometry of Critical Nuclei.

Anal Chem 2020 05 24;92(9):6408-6414. Epub 2020 Apr 24.

Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States.

Gas bubble evolution is present in many electrochemical and photoelectrochemical processes. We previously reported the formation of individual H, N, and O nanobubbles generated from electrocatalytic reduction of H and oxidation of NH and HO, respectively, at Pt nanodisk electrodes in an aqueous solution. All the nanobubbles formed display a dynamic stationary state of a three-phase boundary with an invariant residual current. Read More

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Low-index dielectric metasurfaces supported by metallic substrates for efficient second-harmonic generation in the blue-ultraviolet range.

Kwang-Hyon Kim

Phys Chem Chem Phys 2020 Apr;22(14):7300-7305

Institute of Physics, State Academy of Sciences, Unjong District, Pyongyang, Democratic People's Republic of Korea.

Despite the great importance of high-index materials for dielectric nanophotonics, their optical functionalities are significantly limited for diverse photonic applications and thus, the usability of low-index materials should be explored. This work proposes the use of metallic substrates for low-index dielectric metasurfaces for significantly enhancing the local field and their optical responses. Plasmon-assisted dipole resonances mainly contribute to field enhancement in dielectric nanoparticles comprising the metasurfaces, where the intensity enhancement increases on decreasing the index of the nanoparticles when supported by metallic substrates. Read More

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Developing a time-domain method for simulating statistical behavior of many-emitter systems in the presence of electromagnetic field.

Phys Rev E 2020 Jan;101(1-1):013308

Department of Physics, College of Sciences, Shiraz University, Shiraz 71946-84795, Iran.

In this paper, one of the major shortcomings of the conventional numerical approaches is alleviated by introducing the probabilistic nature of molecular transitions into the framework of classical computational electrodynamics. The main aim is to develop a numerical method which is capable of capturing the statistical attributes caused by the interactions between a group of spontaneous as well as stimulated emitters and the surrounding electromagnetic field. The electromagnetic field is governed by classical Maxwell's equations, while energy is absorbed from and emitted to the (surrounding) field according to the transitions occurring for the emitters, which are governed by time-dependent probability functions. Read More

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January 2020

Ultraviolet Interband Plasmonics With Si Nanostructures.

Nano Lett 2019 11 3;19(11):8040-8048. Epub 2019 Oct 3.

Institute of Materials Research and Engineering , A*STAR (Agency for Science, Technology and Research) , 2 Fusionopolis Way, #08-03 Innovis , 138634 Singapore.

Although Si acts as an electrical semiconductor, it has properties of an optical dielectric. Here, we revisit the behavior of Si as a plasmonic metal. This behavior was previously shown to arise from strong interband transitions that lead to negative permittivity of Si across the ultraviolet spectral range. Read More

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November 2019

Biconcave Carbon Nanodisks for Enhanced Drug Accumulation and Chemo-Photothermal Tumor Therapy.

Adv Healthc Mater 2019 04 11;8(8):e1801505. Epub 2019 Mar 11.

Department of Materials Science and Engineering, University of Washington, Seattle, Washington, DC, 98195, USA.

It is considered a significant challenge to construct nanocarriers that have high drug loading capacity and can overcome physiological barriers to deliver efficacious amounts of drugs to solid tumors. Here, the development of a safe, biconcave carbon nanodisk to address this challenge for treating breast cancer is reported. The nanodisk demonstrates fluorescent imaging capability, an exceedingly high loading capacity (947. Read More

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Impact of chemical interface damping on surface plasmon dephasing.

Faraday Discuss 2019 05;214(0):59-72

Department of Chemical Engineering, University of California, Santa Barbara, USA.

The excellent light harvesting ability of plasmonic nanoparticles makes them promising materials for a variety of technologies that rely on the conversion of photons to energetic charge carriers. In such applications, including photovoltaics and photocatalysis, the excitation of surface plasmons must induce charge transfer across the metal-adsorbate or metal-semiconductor interface. However, there is currently a lack of molecular level understanding of how the presence of a chemical interface impacts surface plasmon dephasing pathways. Read More

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Non-obstructive intracellular nanolasers.

Nat Commun 2018 11 16;9(1):4817. Epub 2018 Nov 16.

SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, KY16 9SS, Scotland, UK.

Molecular dyes, plasmonic nanoparticles and colloidal quantum dots are widely used in biomedical optics. Their operation is usually governed by spontaneous processes, which results in broad spectral features and limited signal-to-noise ratio, thus restricting opportunities for spectral multiplexing and sensing. Lasers provide the ultimate spectral definition and background suppression, and their integration with cells has recently been demonstrated. Read More

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November 2018

Microscopic study of resonant third-harmonic generation from amorphous silicon nanodisk arrays.

Opt Lett 2018 Nov;43(21):5242-5245

A detailed microscopic study of third-harmonic generation (THG) from two-dimensional arrays of sub-wavelength spaced amorphous silicon nanodisks is reported. The arrays are designed to support broadband, minimally angle-sensitive resonances for the fundamental excitation wavelength in the 1500 nm region. This results in resonantly enhanced visible THG in the green spectral range with ∼500-fold enhancement on-resonance, compared to the unpatterned a-Si thin-film. Read More

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November 2018

Nanoplasmonic Ruler for Measuring Separation Distance between Supported Lipid Bilayers and Oxide Surfaces.

Anal Chem 2018 11 16;90(21):12503-12511. Epub 2018 Oct 16.

School of Materials Science and Engineering , Nanyang Technological University , 50 Nanyang Avenue 639798 , Singapore.

Unraveling the details of how supported lipid bilayers (SLBs) are coupled to oxide surfaces is experimentally challenging, and there is an outstanding need to develop highly surface-sensitive measurement strategies to determine SLB separation distances. Indeed, subtle variations in separation distance can be associated with significant differences in bilayer-substrate interaction energy. Herein, we report a nanoplasmonic ruler strategy to measure the absolute separation distance between SLBs and oxide surfaces. Read More

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November 2018

Optical-Force-Dominated Directional Reshaping of Au Nanodisks in Al-Au Heterodimers.

Nano Lett 2018 10 7;18(10):6509-6514. Epub 2018 Sep 7.

The optical reshaping of metallic nanostructures typically requires intense laser pulses to first approach or achieve melting, followed by surface-tension-dominated reshaping, transforming the original nanostructures into more spherical morphologies. Here, we report the directional optical reshaping of the Au nanodisk of an Al-Au heterodimer in the illuminated junction of an atomic force microscope (AFM). Both the heightening and the repositioning of the Au nanodisk component are induced, reducing the gap between the two nanodisks. Read More

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October 2018

Selective Electroless Metallization of Micro- and Nanopatterns via Poly(dopamine) Modification and Palladium Nanoparticle Catalysis for Flexible and Stretchable Electronic Applications.

ACS Appl Mater Interfaces 2018 Aug 21;10(34):28754-28763. Epub 2018 Aug 21.

Department of Mechanical Engineering , The University of Hong Kong , Pokfulam, Hong Kong , China.

The authors report a new patterned electroless metallization process for creating micro- and nanoscale metallic structures on polymeric substrates, which are essential for emerging flexible and stretchable optical and electronic applications. This novel process features a selective adsorption of catalytic Pd nanoparticles (PdNPs) on a lithographically masked poly(dopamine) (PDA) interlayer in situ polymerized on the substrates. The moisture-resistant PDA layer has excellent stability under a harsh electroless plating bath, which enables electroless metallization on versatile substrate materials regardless of their hydrophobicity, and significantly strengthens the attachment of electroless plated metallic structures on the polymeric substrates. Read More

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Enhanced Glioblastoma Targeting Ability of Carfilzomib Enabled by a A7R-Modified Lipid Nanodisk.

Mol Pharm 2018 06 17;15(6):2437-2447. Epub 2018 May 17.

Department of Pharmaceutics, School of Pharmacy, Fudan University, and Key Laboratory of Smart Drug Delivery (Fudan University), Ministry of Education, Shanghai 201203, & State Key Laboratory of Medical Neurobiology, and Collaborative Innovation Center for Brain Science , Fudan University , Shanghai 200032 , China.

The robust proliferation of tumors relies on a rich neovasculature for nutrient supplies. Therefore, a basic strategy of tumor targeting therapy should include not only killing regular cancer cells but also blocking tumor neovasculature. D-peptide A7R, which was previously reported to specifically bind vascular endothelial growth factor receptor 2 (VEGFR2) and neuropilin-1 (NRP-1), could achieve the goal of multitarget recognition. Read More

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Correlation between Gas Bubble Formation and Hydrogen Evolution Reaction Kinetics at Nanoelectrodes.

Langmuir 2018 04 4;34(15):4554-4559. Epub 2018 Apr 4.

Department of Chemistry , Wayne State University , Detroit , Michigan 48202 , United States.

We report the correlation between H gas bubble formation potential and hydrogen evolution reaction (HER) activity for Au and Pt nanodisk electrodes (NEs). Microkinetic models were formulated to obtain the HER kinetic information for individual Au and Pt NEs. We found that the rate-determining steps for the HER at Au and Pt NEs were the Volmer step and the Heyrovsky step, respectively. Read More

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How Effective is Plasmonic Enhancement of Colloidal Quantum Dots for Color-Conversion Light-Emitting Devices?

Small 2017 12 9;13(48). Epub 2017 Nov 9.

Department of Physics, Korea Advanced Institute of Science and Technology, Yuseong-gu, Daejeon, 34141, Republic of Korea.

Enhancing the fluorescence intensity of colloidal quantum dots (QDs) in case of color-conversion type QD light-emitting devices (LEDs) is very significant due to the large loss of QDs and their quantum yields during fabrication processes, such as patterning and spin-coating, and can therefore improve cost-effectiveness. Understanding the enhancement process is crucial for the design of metallic nanostructure substrates for enhancing the fluorescence of colloidal QDs. In this work, improved color conversion of colloidal green and red QDs coupled with aluminum (Al) and silver (Ag) nanodisk (ND) arrays designed by in-depth systematic finite-difference time domain simulations of excitation, spontaneous emission, and quantum efficiency enhancement is reported. Read More

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December 2017

Multiple-Patterning Nanosphere Lithography for Fabricating Periodic Three-Dimensional Hierarchical Nanostructures.

ACS Nano 2017 10 2;11(10):10384-10391. Epub 2017 Oct 2.

California NanoSystems Institute, ‡Department of Chemistry and Biochemistry, §Department of Pediatrics, David Geffen School of Medicine, ∥Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, ⊥Children's Discovery and Innovation Institute, and #Department of Materials Science and Engineering, University of California, Los Angeles , Los Angeles, California 90095, United States.

While three-dimensional (3D) configurable hierarchical nanostructures have wide ranging applications in electronics, biology, and optics, finding scalable approaches remains a challenge. We report a robust and general strategy called multiple-patterning nanosphere lithography (MP-NSL) for the fabrication of periodic 3D hierarchical nanostructures in a highly scalable and tunable manner. This nanofabrication technique exploits the selected and repeated etching of polymer nanospheres that serve as resists and that can be shaped in parallel for each processing step. Read More

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October 2017

High Figure of Merit (FOM) of Bragg Modes in Au-Coated Nanodisk Arrays for Plasmonic Sensing.

Small 2017 10 21;13(38). Epub 2017 Aug 21.

Département de chimie, Université de Montréal, CP. 6128, Succ. Centre-Ville, Montréal, QC, H3C 3J7, Canada.

Gold-coated nanodisk arrays of nearly micron periodicity are reported that have high figure of merit (FOM) and sensitivity necessary for plasmonic refractometric sensing, with the added benefit of suitability for surface-enhanced Raman scattering (SERS), large-scale microfabrication using standard photolithographic techniques and a simple instrumental setup. Gold nanodisk arrays are covered with a gold layer to excite the Bragg modes (BM), which are the propagative surface plasmons localized by the diffraction from the disk array. This generates surface-guided modes, localized as standing waves, leading to highly confined fields confirmed by a mapping of the SERS intensity and numerical simulations with 3D finite element method. Read More

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October 2017

Stacked Gold Nanodisks for Bimodal Photoacoustic and Optical Coherence Imaging.

ACS Nano 2017 06 30;11(6):6225-6232. Epub 2017 May 30.

Center for Nano-Bio Measurement, Korea Research Institute of Standards and Science , Daejeon 305-340, Republic of Korea.

Herein, we report on biological imaging nanoprobes: physically synthesized gold nanodisks that have inherent optical advantages-a wide range of resonant wavelengths, tunable ratio of light absorption-to-scattering, and responsiveness to random incident light-due to their two-dimensional circular nanostructure. Based on our proposed physical synthesis where gold is vacuum deposited onto a prepatterned polymer template and released from the substrate in the form of a nanodisk, monodisperse two-dimensional gold nanodisks were prepared with independent control of their diameter and thickness. The optical benefits of the Au nanodisk were successfully demonstrated by the measurement of light absorbance of the nanodisks and the application of stacked nanodisks, where a smaller sized Au nanodisk was laid atop a larger nanodisk, as bimodal contrast agents for photoacoustic microscopy and optical coherence tomography. Read More

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Thermoplasmonic Semitransparent Nanohole Electrodes.

Nano Lett 2017 05 28;17(5):3145-3151. Epub 2017 Apr 28.

Laboratory of Organic Electronics, Linköping University , SE-601 74 Norrköping, Sweden.

Nonradiative decay of plasmons in metallic nanostructures offers unique means for light-to-heat conversion at the nanoscale. Typical thermoplasmonic systems utilize discrete particles, while metal nanohole arrays were instead considered suitable as heat sinks to reduce heating effects. By contrast, we show for the first time that under uniform broadband illumination (e. Read More

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Quantification of circulating antigen peptides allows rapid diagnosis of active disease and treatment monitoring.

Proc Natl Acad Sci U S A 2017 04 27;114(15):3969-3974. Epub 2017 Mar 27.

Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030;

Tuberculosis (TB) is a major global health threat, resulting in an urgent unmet need for a rapid, non-sputum-based quantitative test to detect active () infections in clinically diverse populations and quickly assess treatment responses for emerging drug-resistant strains. We have identified -specific peptide fragments and developed a method to rapidly quantify their serum concentrations, using antibody-labeled and energy-focusing porous discoidal silicon nanoparticles (nanodisks) and high-throughput mass spectrometry (MS) to enhance sensitivity and specificity. NanoDisk-MS diagnosed active cases with high sensitivity and specificity in a case-control study with cohorts reflecting the complexity of clinical practice. Read More

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Electrochemical Nucleation of Stable N2 Nanobubbles at Pt Nanoelectrodes.

J Am Chem Soc 2015 Sep 10;137(37):12064-9. Epub 2015 Sep 10.

Department of Chemistry, University of Utah , 315 S 1400 E, Salt Lake City, Utah 84112, United States.

Exploring the nucleation of gas bubbles at interfaces is of fundamental interest. Herein, we report the nucleation of individual N2 nanobubbles at Pt nanodisk electrodes (6–90 nm) via the irreversible electrooxidation of hydrazine (N2H4 → N2 + 4H(+) + 4e(–)). The nucleation and growth of a stable N2 nanobubble at the Pt electrode is indicated by a sudden drop in voltammetric current, a consequence of restricted mass transport of N2H4 to the electrode surface following the liquid-to-gas phase transition. Read More

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September 2015

Nanoscale optical properties of indium gallium nitride/gallium nitride nanodisk-in-rod heterostructures.

ACS Nano 2015 Mar 12;9(3):2868-75. Epub 2015 Feb 12.

†Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.

III-nitride based nanorods and nanowires offer great potential for optoelectronic applications such as light emitting diodes or nanolasers. We report nanoscale optical studies of InGaN/GaN nanodisk-in-rod heterostructures to quantify uniformity of light emission on the ensemble level, as well as the emission characteristics from individual InGaN nanodisks. Despite the high overall luminescence efficiency, spectral and intensity inhomogeneities were observed and directly correlated to the compositional variations among nanodisks and to the presence of structural defect, respectively. Read More

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Morphology-controlled self-assembly and synthesis of photocatalytic nanocrystals.

Nano Lett 2014 Dec 6;14(12):7175-9. Epub 2014 Nov 6.

Key Laboratory for Special Functional Materials of the Ministry of Education, Henan University , Kaifeng 475004, People's Repubic of China.

Abilities to control the size and shape of nanocrystals in order to tune functional properties are an important grand challenge. Here we report a surfactant self-assembly induced micelle encapsulation method to fabricate porphyrin nanocrystals using the optically active precursor zinc porphyrin (ZnTPP). Through confined noncovalent interactions of ZnTPP within surfactant micelles, nanocrystals with a series of morphologies including nanodisk, tetragonal rod, and hexagonal rod, as well as amorphous spherical particle are synthesized with controlled size and dimension. Read More

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December 2014

"Red-to-blue" colorimetric detection of cysteine via anti-etching of silver nanoprisms.

Nanoscale 2014 Sep 1;6(18):10631-7. Epub 2014 Aug 1.

Key Laboratory of Magnetic Materials and Devices & Division of Functional Materials and Nano Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China.

The reported strategies for cysteine (Cys) colorimetric detection based on noble metal nanomaterials include triggering aggregation, etching or fluorescence quenching of nanomaterials by Cys. In this study, we propose a new strategy for Cys colorimetric detection, i.e. Read More

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September 2014

An enhanced LSPR fiber-optic nanoprobe for ultrasensitive detection of protein biomarkers.

Biosens Bioelectron 2014 Nov 11;61:95-101. Epub 2014 May 11.

Center for Applied Optics, University of Alabama at Huntsville, Huntsville, AL 35899, USA; Department of Electrical and Computer Engineering, University of Alabama at Huntsville, Huntsville, AL 35899, USA.

A miniaturized, localized surface plasmon resonance (LSPR)-coupled fiber-optic (FO) nanoprobe is reported as a biosensor that is capable of label-free, sensitive detection of a cancer protein biomarker, free prostate specific antigen (f-PSA). The biosensor is based on the LSPR at the reusable dielectric-metallic hybrid interface with a robust, gold nano-disk array at the fiber end facet that is directly fabricated using EBL and metal lift-off process. The f-PSA has been detected with a mouse anti-human PSA monoclonal antibody (mAb) as a specific receptor linked with a self-assembled monolayer at the LSPR-FO facet surfaces. Read More

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November 2014

Efficient spin-light emitting diodes based on InGaN/GaN quantum disks at room temperature: a new self-polarized paradigm.

Nano Lett 2014 Jun 8;14(6):3130-7. Epub 2014 May 8.

Department of Physics, National Taiwan University , Taipei 106, Taiwan.

A well-behaved spin-light emitting diode (LED) composed of InGaN/GaN multiple quantum disks (MQDs), ferromagnetic contact, and Fe3O4 nanoparticles has been designed, fabricated, and characterized. The degree of circular polarization of electroluminescence (EL) can reach up to a high value of 10.9% at room temperature in a low magnetic field of 0. Read More

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Directional emission from ZnO hexagonal disks.

ACS Appl Mater Interfaces 2014 Mar 19;6(5):3093-8. Epub 2014 Feb 19.

State Key Laboratory of Optoelectronic Materials and Technologies, Institute of Optoelectronic and Functional Composite Materials, Nanotechnology Research Center, School of Physics & Engineering, Sun Yat-sen University , Guangzhou 510275, Guangdong, P. R. China.

Lots of theories and experiments have so far tried to acquire the directional emission with whispering-gallery modes (WGMs) from micro- and nanostructures, which will enhance the applications of micro- and nanoscaled whispering-gallery resonators in optoelectronic devices. Here for the first time we report a series of directional emission patterns with WGMs from the single ZnO hexagonal micro- and nanodisk. Based on the cathodeluminescence technique, we observed far-field emissions from ZnO hexagonal micro- and nanodisks in four geometries with different deformations. Read More

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Electrogeneration of single nanobubbles at sub-50-nm-radius platinum nanodisk electrodes.

Langmuir 2013 Sep 19;29(35):11169-75. Epub 2013 Aug 19.

Department of Chemistry, University of Utah, 315 S 1400 E, Salt Lake City, Utah 84112, USA.

The electrochemical generation of individual H(2) nanobubbles at Pt nanodisk electrodes immersed in a 0.5 M H(2)SO(4) solution is reported. A sudden drop in current associated with the transport-limited reduction of protons is observed in the i–V response at Pt nanodisk electrodes with radii of less than 50 nm. Read More

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September 2013

Construction of GPx active centers on natural protein nanodisk/nanotube: a new way to develop artificial nanoenzyme.

ACS Nano 2012 Oct 25;6(10):8692-701. Epub 2012 Sep 25.

State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China.

Construction of catalytic centers on natural protein aggregates is a challenging topic in biomaterial and biomedicine research. Here we report a novel construction of artificial nanoenzyme with glutathione peroxidase (GPx)-like function. By engineering the surface of tobacco mosaic virus (TMV) coat protein, the main catalytic components of GPx were fabricated on TMV protein monomers. Read More

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October 2012