bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Towards Comprehensive Control of Electrochemical Reactions through Electrolyte Design: A Lithium Oxygen Battery Case Study
Authors: Leverick Graham , Tulodziecki Michal , Katayama Yu , Tatara Ryoichi , Feng Shuting , Bardé Fanny , Shao-Horn Yang
Published: February 2020

While the importance of electrolyte chemical stability and ionic conductivity has been known since the very first batteries, findings in the lithium-oxygen battery community over the past few years have revealed that the electrolyte can dramatically alter the reaction pathway, battery capacity and rate. In this talk, the various mechanisms through which electrolyte has been found to interact with lithium-oxygen battery chemistry are explored. This includes recent results on the influence of solvent, counter anion and lithium ion concentration on the thermodynamics and kinetics of oxygen reduction as well as solvent-water-halide interactions and their impact on the viability of lithium halide redox mediators. Based on these new understandings, a framework for rational electrolyte design in lithium-oxygen batteries for controlling the reaction pathway and properties is discussed. This framework is based on competing interactions between solvent, co-solvent/additives as well as charged species in the electrolyte and how these interactions can be altered by changing the nature and concentration of species present in the electrolyte. Opportunities and perspectives for unlocking this approach in other reactions will also be considered.

Figure 1
(Invited) Mechanistic Details of Protonic Solar Cells Formed Via Covalent Modification of Passive Ion-Exchange Membranes with Photoacid Dye Molecules
Authors: White William , Sanborn Christopher D. , Schwartz Eric , Luo Simon , Fabian David M. , Renna Lawrence A. , Ardo Shane
Published: February 2020

Many electrochemical technologies require ion-conducting polymer electrolytes. These polymers are passive in that electric bias across them drives ion migration in the thermodynamically favored direction.1 Recently, my group engineered two important features into ion-selective polymer membranes to introduce the active function of photovoltaic action and demonstration of an ionic solar cell. These features were covalent bonding of photoacid dyes to the polymers such that absorption of visible light liberated protons, and polymers with charge-selective contacts to facilitate separation and collection of H+ and OH–.2,3 The most effective designs join a monopolar cation-selective polymer to a monopolar anion-selective polymer to form a bipolar membrane whose electrostatics and thermodynamics mimic those of a rectifying semiconductor pn-junction diode. Illumination from either side of a photoacid-modified bipolar membrane resulted in photoinduced deprotonation of photoacids followed by charge separation in a direction dictated by the built-in electrostatic asymmetry in the polymers.

Performance optimization is underway to increase the state-of-the-art voltage to beyond 120 mV and state-of-the-art current to beyond 100 μA/cm2. The aim of these efforts is to gain a strong fundamental understanding of dye and material function using a variety of techniques. These include electrochemical impedance spectroscopy to quantify properties of capacitive space-charge regions; pulsed-laser spectroscopy to elucidate light-driven mechanisms of ion transfer and transport; finite-element numerical modeling to understand photoacid dye kinetics and drift–diffusion generation–recombination membrane physics; and optical, electron, and ion microscopies to elucidate materials morphology and function.

Collectively, these photo-responsive polymers represent a new class of materials that use light to trigger changes in local pH and/or electrostatic potential. These local changes can be used to affect macroscopic processes such as direct solar desalination of salt water or triggering redox chemistry or chemical catalysis.

Acknowledgment: This work is supported by a Moore Inventor Fellowship from the Gordon & Betty Moore Foundation, under Grant #5641.

References:

Reiter, R. S.; White, W.; Ardo, S. Journal of The Electrochemical Society, 2016, 163, H3132.

White, W.; Sanborn, C. D.; Reiter, R. S.; Fabian, D. M.; Ardo, S. Journal of the American Chemical Society, 2017, 139, 11726.

White, W.; Sanborn, C. D.; Fabian, D. M.; Ardo, S. Joule, 2017, Accepted Manuscript, DOI: 10.1016/j.joule.2017.10.015.
Electrochemical Immunosensors Based on 2-Electrode System of 3D Interdigitated Electrodes Array
Authors: Lee Dahye , Chung Taek Dong
Published: February 2020

Practical biosensors require miniaturized device and simplified system. These requirements are fulfilled by fabricating 3-dimensional (3D) interdigitated array (IDA) electrodes and eliminating reference electrode. In this presentation, we demonstrate electrochemical immunosensors based on 2-electrode (2E) system operated by redox cycling on two working electrodes without reference electrode and counter electrode. The redox cycling between two IDA electrodes, on the ceiling as well as the bottom of the microchannel, can make faradaic signal effectively amplified. In the proposed 2E system, electrochemical potential is determined by an immobilized electron transfer mediator, poly(methylene green) (PMG) on indium-tin oxide electrode surface. PMG works as a good mediator for redox of 4-aminophenol, which is the enzymatic product for immunosensing. Harnessing such a 3D IDA immunosensor of 2E operating system, we detected human Creatine Kinase-MB, a specific biomarker of myocardial damage, down to ~ pg/mL level. Moreover, this system has the potential that multiple 3D IDA electrodes embedded in a single chip can simultaneously analyze several mixed biomarkers and can be miniaturized small enough to be portable.
Conductivity of Garnet-Type Lithium Lanthanum Zirconate Based Composite Electrolytes
Authors: Zhang Xingxing , Fergus Jeffrey
Published: February 2020

Garnet-type Li7La3Zr2O12 (LLZO) is an attractive solid electrolyte material for lithium ion batteries. LLZO has good chemical stability and high ionic conductivity, but it is also rigid and brittle, which may result in poor contact with electrodes and mechanical failure. Composite electrolytes, which combine the advantages of both LLZO and solid polymer electrolyte, are promising solid electrolytes with high ionic conductivity, good chemical stability and mechanical properties. In this work, LLZO based composite electrolytes have been prepared and evaluated with materials characterization techniques and impedance spectroscopy.
Electrochemical Characterization of the Lithium-Ion Cells Assembled with Ester-Based Electrolyte at Low Temperature
Authors: Park Seung Hark , Kim Sang-Hyung , Kim Soojin , Kim Dong-Won
Published: February 2020

Lithium-ion batteries (LIBs) have become promising power sources in the field of electric vehicles (EVs) and energy storage systems (ESS) due to their high energy density and long cycle life. However, poor performance of LIBs at low temperature limits their applications, and it is thus essential to improve the low temperature cycling performance. The main requirements of liquid electrolyte for LIBs are high ion conductivity, low viscosity, wide potential window and wide liquid range. One of the most important factors for improving low temperature performance of LIBs is extension of liquid phase range, which can be affected by freezing point of organic solvent. However, it is well known that carbonate-based solvents commonly used in current LIBs exhibit poor ion conductivity and low diffusivity of lithium ion in the electrode at low temperature. A lot of approaches such as using additives to form stable SEI layer and introducing co-solvent to modify electrolyte properties have been adopted to improve cell performance at low temperature. In this study, we propose ester-based solvents to improve low temperature performance of LIBs, which exhibit stable and good cycle performance at low temperature. Analysis techniques such as electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) have been implemented to understand the improvement of low temperature performance of LIBs.
Development of Functionalized "UiO-66 MOF" Embedded Cellulose Nanocomposites for Photoelectrochemical Water Splitting
Authors: Shanahan Jordan James , Bueno Liana , Kissel Daniel S. , Keleher Jason J.
Published: February 2020

Economic distress resulting from global dependence on diminishing fossil fuels that adversely impact the environment has led to increased interest in alternative green energy technologies. The photoelectrochemical cell (PEC), provides an attractive green energy solution that incorporates semiconductor materials capable of absorbing visible light to power the splitting of water and create H2 gas, a clean fuel source. PEC systems today, however, are not yet commercially viable due to a lack in efficiency, stability and cost effectiveness. Therefore, the goal of this work is to create a novel, low price semiconducting material to be used as an electrode in a PEC system. This will be accomplished by incorporating the zirconium based Metal Organic Framework (MOF) UiO-66 into a celllulostic network to create a flexible, semiconducting material. The UiO-66 MOF offers a combination of defect sites on the Zr metal cluster and an aromatic linker allowing for light absorption coupled with efficient charge transport. Unfortunately, UiO-66 absorbs in the UV region (2% of sunlight), but its high stability and conjugated organic ligands make it ideal for photosensitization. Simple post synthetic modifications (PSM) can be done to improve light harvesting and electron transport capabilities within the cellulose network. Modifications incorporated in this work include the use of polyaniline crosslinkers as well as metal nanoparticle doping. Conductivity of each material was characterized using a four point probe and measuring current response to applied stepwise voltage. PEC performance was determined by illuminating cell with light and measuring voltage, current and product evolution. Overall, this work provides a foundational design of low cost working electrodes for use in PEC systems, that can lead to future modifications to optimize cell performance.
Effect of Anode Channel Depth on Cell Performance in Polymer Electrolyte Membrane Water Electrolyser
Authors: Majasan Jude Olaoluwa , Cho Jason I. S. , Dedigama Ishanka , Shearing Paul R. , Brett Daniel J.L.
Published: February 2020

The Bipolar/Flow field plate is a vital component of Polymer Electrolyte Membrane Water Electrolysers (PEMWE) which enables electronic conduction, provide mechanical support to the cell and facilitates mass transport of liquid water and produced gases to and from the electrocatalyst surface. From a mass transport viewpoint, especially at high current density operation, optimizing the dimensions and configuration of the flow field plate is crucial to reducing mass transport limitation and achieve improved cell performance. This work investigates the effect of channel depth of the anode flow field plate on performance of a PEM Water Electrolyser using polarization curve and Electrochemical Impedance Spectroscopy technique. A single electrolyser cell with flow field plate having a single straight channel was employed having the channel depth varied from 3.0 mm to 8.0 mm and the cell performance was studied at current densities up to 2 A/cm2. The impedance spectroscopy results show that the effect of channel depth on cell performance is negligible at low and medium current densities, but significant at high current densities. The result indicate that the two-phase flow liquid/gas interactions in the flow channel and the flow regime of operation have a direct influence on mass transport losses and overall performance in the PEM Water Electrolyser. Furthermore, the impedance spectroscopy result at high current densities shows that, generally, deeper channels show better performance than shallower channels which suggests that the effective mass transfer area at the surface of the gas diffusion layer increases with increase in channel depth thus yielding improved mass transport. However, the best performance was observed at 4.5 mm depth which suggests that there exist an optimal channel depth where an increase or decrease in depth would lead to loss of performance. This is attributed to the trade-off between reduced liquid flow velocity and reduced surface coverage of gas bubble/slug in the channel with increasing channel depth in the PEMWE flow field.

Fig 1: Effect of channel depth on cell performance at (a) low, (b) medium and (c) high current density at water flow rate of 40 mL/min and inlet water temperature of 80°C.

Figure 1
(Invited) Carbon Nanomaterials for Flexible and Stretchable Devices
Authors: Zhang Yingying , Wang Huimin , Wang Chunya , Zhang Mingchao
Published: February 2020

The development of flexible electronics and equipment attracts significant interests in recent years. It is of great importance to develop flexible and wearable energy storage devices for wearable and portable devices. Carbon nanomaterials have large surface area, good conductivity and excellent mechanical and chemical stability, enabling their applications in high performance energy conversion and energy storage devices. In this talk, I will present fiber-shaped ultra-stretchable and flexible supercapacitor made of carbon nanotube fibers, film-shaped stretchable supercapacitors and flexible Zn-air batteries using stretchable graphitized natural fabrics as electrodes. The ultra-stretchable wire-shaped supercapacitor was made by winding two carbon nanotube@graphene@MnO2 fibers around a superelastic core fiber. The supercapacitor can sustain tensile strain up to 850%, which is hitherto the highest value, while keeping stable electrochemical performance. We further demonstrated that there devices can be assembled with carbon-based flexible sensors into wearable smart systems. These strategy paves new ways for the fabrication of high performance wearable energy storage devices and flexible electronics.

References:

Huimin Wang, Chunya Wang, Muqiang Jian, Qi Wang, Kailun Xia, Zhe Yin, Mingchao Zhang, Xiaoping Liang, Yingying Zhang*. Superelastic Wire-shaped Supercapacitor Sustaining 850% Tensile Strain Based on Carbon Nanotube@Graphene Fiber. Nano Research 2017 1007/s12274-017-1782-1

Chunya Wang, Mingchao Zhang, Kailun Xia, Xueqin Gong, Huimin Wang, Zhe Yin, Baolu Guan, and Yingying Zhang*. Intrinsically Stretchable and Conductive Textile by a Scalable Process for Elastic Wearable Electronics. ACS Appl. Mater. Interfaces
2017, 9 (15), 13331–13338.

Mingchao Zhang, Chunya Wang; Xiaoping Liang, Zhe Yin, Kailun Xia, Huimin Wang, Muqiang Jian, Yingying Zhang. Weft-knitted fabric for highly-stretchable and low-voltage wearable heater. Advanced Electronic Materials DOI 10.1002/aelm.201700193

Chunya Wang, Xiao Li, Enlai Gao, Muqiang Jian, Kailun Xia, Qi Wang, Zhiping Xu, Tianling Ren, Yingying Zhang*. Carbonized Silk Fabric for Ultra-stretchable, Highly Sensitive and Wearable Strain Sensors. Advanced Materials 2016, 28, 6640.
Facile Synthesis of in-Plane Graphene Micro-Supercapacitor Using Flash Reduction
Authors: Kang Seok Hun , You In-Kyu , Kim In Gyoo , Sul Ji Hwan
Published: February 2020

Here we present a simple fabrication method of in-plane graphene micro-supercapacitor using flash light irradiation. Flash light reduction of graphene oxide (GO) is an efficient method of producing high quality reduced graphene oxide (rGO) in room temperature ambient conditions without the help of hazardous reducing agents (e.g. hydrazine, hydrogen iodide). The entire process is low cost and is capable of large scale fabrication. By carefully optimizing the photo-thermal reduction conditions and utilizing shadow mask in a similar manner as for photolithography, all-carbon, monolithic supercapacitor with interdigital finger structure can be fabricated in a simple irradiation step that occurs in less than one second. Microscale thinness of the device makes it highly flexible and thus useful for next generation electronics, such as wearable devices. The as-formed supercapacitor benefits from the in-plane structure, which allows full utilization of high surface area of graphene layers and rapid electrolyte diffusion that results in high energy and power densities.
Preparation of Polymer-Derived Nitrogen-Doped Hollow Carbon Nanofiber As a Free Standing Oxygen Electrode for Li-O2 Battery
Authors: Lim Katie Heeyum , Kweon Heejun , Kim Hansung
Published: February 2020

Li-O2 battery has got much attention as a beyond Li-ion battery (LIB), due to its higher energy density and exceeding specific capacity than those of commercial LIB. Though it has a promising potential for large-scale energy storage device, Li-O2 battery still has several problems to be overcome in aspects of poor rate capability and limited stability. Especially, the oxygen electrode is one of the most closely related component to the performance of Li-O2 battery since it is the actual site for formation and decomposition of discharge products. Thus, in order to achieve the Li-O2 battery with improved performance, the oxygen electrode should provide favorable structure for not only discharge product storage, but also facile transfer of reactants such as Li ion and O2. Moreover, bicatalytic activity for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is also significant on oxygen electrode by determining the morphology of discharge product. Furthermore, the oxygen electrode has to be chemically and electrochemically stable as well for extended durability of Li-O2 battery.

In this regards, we develop a binder free oxygen electrode composed of nitrogen-doped hollow carbon nanofiber, which is derived from nitrogen-containing polymer. Each carbon nanofiber has an empty space inside the fiber even after the heat treatment at high temperature of 900 °C, and it can facilitate the mass transfer of reactants. Due to this unique structure and high nitrogen content of 4.5 at. %, nitrogen-doped hollow carbon nanofiber indicates the lower ORR overpotential and larger discharge capacity than commercial carbon material, Super P, as shown in Fig. 1. Interestingly, it shows the reduced ORR/OER overpotential which is lower than 1 V with the curtaining capacity of 500 mAh g-1
carbon. The notably reduced overpotential might be attributable to the synergetic effect of nitrogen doping, unique structure of hollow carbon nanofiber and absence of binder by promoting the catalytic activity, facilitating the mass transfer and suppressing the side reactions, respectively. The effects of heat treatment temperature and metal incorporation are also investigated and optimized. As for the result, it can be demonstrated that the binder-free nitrogen-doped hollow carbon nanofiber is an enhanced oxygen electrode of Li-O2 battery.

Figure 1
Non Noble Metal Catalysts for the Oxygen Reduction Reaction from Mixed MOFs
Authors: Huang Jilin , Lin Zhipeng , Zhan Yunfeng , Meng Hui
Published: February 2020

Aiming at reducing the cost of fuel cells, the research of non noble metal catalyst has been a hot topic. Recently the performance of non noble metal catalyst has been improved to a level that is similar with noble metal catalyst, leaving the stability a problem to be resolved. The development of non noble metal catalyst has three stages. The first stage is based on porphyrin or phthalocyanine, where nitrogen and iron are from the same precursor. The catalyst is usually pyrolyzed at 400-1000ºC in inert atmosphere [1]；The second stage is characterized by the division of nitrogen and iron precursor, inorganic salt is used as iron precursor and nitrogen containing organic molecular is nitrogen precursor, or inorganic salt is used as iron precursor and NH3 is nitrogen precursor. Both is pyrolyzed at 400-1000ºC in inert atmosphere[2]；The performance of these two kinds of catalysts are poor before the breakthrough made by Pro. Jean-Pol Dodelet from INRS Canada, who improved the MEA performance to 0.26Acm-2 at 0.7V[3]。The performance is then greatly improved at the third stage of non noble metal catalyst, which can be characterized by loading iron salt and nitrogen precursor on MOFs, the pyrolysis is also necessary. The performance of this kind of catalyst is greatly improved. For example the H2/O2 MEA performance of 0.7Acm-2 at 0.7V by Jean-Pol Dodelet[4]; H2/O2 MEA performance of 0.6Acm-2 at 0.7V by Dijia Liu from Argonne National Lab[5]; H2/air MEA performance of 0.3Acm-2 at 0.7V by Sanjeev Mukerjee from Northeastern University6]. In this work we report some recent work of our group in the performance of non noble metal catalyst based on mixed MOFs materials. A preliminary result of H2/O2 MEA performance of 0.2Acm-2 at 0.7V is reached, which is improving.

Figure (a): The ORR performance of the as prepared non noble metal catalyst in O2 saturated 0.1M HClO4 solution at 1600rpm; (b): H2/O2 MEA performance of the as prepared non noble metal catalyst

References:

Jasinski, R., A New Fuel Cell Cathode Catalyst. Nature, 1964. 201(4925): p. 1212-1213.

Jaouen, F., et al., Non-noble electrocatalysts for O-2 reduction: How does heat treatment affect their activity and structure? Part II. Structural changes observed by electron microscopy, Raman, and mass spectroscopy. Journal of Physical Chemistry C, 2007. 111(16): p. 5971-5976.

Lefèvre, M., et al., Iron-Based Catalysts with Improved Oxygen Reduction Activity in Polymer Electrolyte Fuel Cells. Science, 2009. 324(5923): p. 71-74.

Proietti, E., et al., Iron-based cathode catalyst with enhanced power density in polymer electrolyte membrane fuel cells. Nat Commun, 2011. 2: p. 416.

Barkholtz, H.M., et al., Highly Active Non-PGM Catalysts Prepared from Metal Organic Frameworks. Catalysts, 2015. 5(2): p. 955-965.

Li, J., et al., Structural and mechanistic basis for the high activity of Fe-N-C catalysts toward oxygen reduction. Energy & Environmental Science, 2016. 9(7): p. 2418-2432.
(Invited) Air-Stability Mechanism of n-Type Single-Walledcarbon Nanotube Sheet Doped with Benzimidazole Derivative
Authors: Fujigaya Tsuyohiko , Staykov Aleksandar , Huang Wenxin , Nakashima Yuki
Published: February 2020

Thermoelectric (TE) conversion is one of the most promising methods for the generation of cost-effective electricity. TE devices have applications in many fields especially microelectronics devices due to their simple device structures. TE generation using Seebeck effect requires both n-type and p-type TE materials for the efficient conversion; however, deterioration of n-type nature due to air oxidation has been the critical issue. Recently, we reported single-walled carbon nanotubes (SWCNT) sheet doped by 2-(2-methoxyphenyl)-1,3-dimethyl-2,3-dihydro-1H-benzimidazole (o-MeO-DMBI) showed n-type property and remarkable air-stability. We chose o-MeO-DMBI because of the following reasons; i) o-MeO-DMBI is stable under atmospheric conditions, ii) the cationic form of o-MeO-DMBI is also stable and, iii) n-doping of the other carbon materials such as fullerene and graphene has already been reported. Here, we study the mechanism of the air stability of o-MeO-DMBI-doped SWCNT films by changing the doping level. eDIPS (Meijo Nano Carbon, EC1.5) was used as SWCNT. SWCNT films were dipped in the 0.01, 0.1, 1.0, 10 and 50 mM ethanol solutions of o-MeO-DMBI for 10 min and dried in vacuum at room temperature for 12 h. The time course of Seebeck coefficient of the SWCNT films doped with various concentration of o-MeO-DMBI solution was studied. It is noted that the films were kept under air condition at room temperature to evaluate the air stability of the o-MeO-DMBI-doped SWCNT films. Positive value of Seebeck coefficient for 0.01 and 0.1 mM doped films indicated p-type, and negative value for 1.0, 10 and 50 mM doped films showed n-type nature of the films. Interestingly, we found that Seebeck coefficient of 1.0 mM doped film changed to positive, while 10 mM doped film showed stable negative value. From above results, we conclude that the mechanism of the air-stabilization of n-doping is the passivation effect by the formation of o-MeO-DMBI layer onto the surface of SWCNT films
(Invited) Harvesting Torsional and Tensile Mechanical Energy as Electrical Energy Using Nanofiber Yarns
Authors: Baughman Ray H.
Published: February 2020

Mechanical energy harvesters are needed for such diverse applications as self-powered wireless sensors, structural and human health monitoring systems, and cheaply harvesting energy from ocean waves. We report nanofiber yarn harvesters that electrochemically convert tensile or torsional mechanical energy into electrical energy. Stretching coiled yarns generated 250 W/kg of peak electrical power when cycled up to 30 Hz, and up to 41.2 J/kg of electrical energy per mechanical cycle, when normalized to the weight of the harvester yarn. Unlike for other harvesters, torsional rotation produces both tensile and torsional energy harvesting and no bias voltage is required, even when electrochemically operating in salt water. Since homochiral and heterochiral coiled harvester yarns provide oppositely directed potential changes when stretched, both contribute to output power in a dual-electrode yarn. These energy harvesters were used in the ocean to harvest wave energy, combined with thermally-driven artificial muscles to convert temperature fluctuations to electrical energy, sewn into textiles for use as self-powered respiration sensors, and used to power a LED and to charge a storage capacitor. The development of “piezoelectrochemical spectroscopy” and insights into the hierarchical origins of capacitance increased fundamental understanding. This work is collaborative with Seon Jeong Kim, Shi Hyeong Kim, Keon Jung Kim, Tae Jin Mun, Changsoon Choi, and Dong Youn Lee of Hanyang University; Carter S. Haines, Na Li, Jiangtao Di, Young Jun Oh, Juan Pablo Oviedo, Shaoli Fang, Kyeongjae Cho, Moon Kim, Enlai Gao, Dawood Albarq, and Xavier Lepró of the University of Texas at Dallas; Julia Bykova and Raquel Ovalle-Robles of Lintec of America; Nan Jiang, Zunfeng Liu, and Run Wang of the Jiangnan Graphene Research Institute; Prashant Kumar, Rui Qiao, and Shashank Priya of Virtinia Tech; and Matthew Steven Lucas, Lawrence F. Drummy, and Benji Maruyama of the Wright-Patterson Air Force Research Laboratory.
Carbon Nanotube Microparticles for Lithium-Sulfur Battery Cathodes
Authors: Gueon Donghee , Moon Jun Hyuk
Published: February 2020

A carbon host capable of effectively and uniformly incorporating a high sulfur content is the key to the development of lithium-sulfur batteries (LSB). This study exhibits carbon nanotube microparticle as a sulfur host of a LSB cathode. Due to the macropores, our CNTPs achieved uniform sulfur infilteration without sulfur residue. Additionally, the macropores enhanced the micropore fraction and thereby improved the sulfur confinement. Our cathode showed a high reversible capacity of approximately 1300 m/g at a current density of 0.2 C even at a high sulfur content of 70 wt%. A high capacity retention of 74% was observed with a 10-fold current density increase.
Graphene Oxide-Iron Oxide Nanoconjugates for Drug Transport, Biosensing and Bimodal Fluorescence/Magnetic Resonance Imaging
Authors: Gonzalez-Rodriguez Roberto , Sizemore Elizabeth , Naumov Anton V
Published: February 2020

Due to its remarkable properties, graphene has become a basis of many novel microelectronic devices. However its functional derivatives including graphene oxide (GO) can be mass-produced at lower costs and retain many properties of graphene in addition being water soluble. GO also exhibits fluorescence in the visible/near-IR suitable for applications in optoelectronics and biomedicine. The most novel biomedical applications of GO include, sensing, molecular imaging in visible/near-IR and drug delivery. In all these applications GO was mostly proposed as an agent for in-vitro or ex-vivo imaging due to its emission in visible or near-IR. In this work we combine GO with superparamagnetic iron oxide nanoparticles (Fe3O4 NPs) to provide the unique capacity of multimodal imaging and magnetic targeted drug delivery.

Fe3O4 NPs are biocompatible and have been used as biosensing, magnetic assisted drug delivery system and also a magnetic resonance contrast agent for MRI. Additionally, these NPs can be attracted by a magnet allowing for targeting of the attached therapeutics via the magnetic field to specific organ and/or cancer tumor.

In this work, we fabricate nanoconjugates of GO- Fe3O4 for combining GO fluorescence, sensing and drug delivery properties with magnetic targeting and a possibility of MRI imaging provided by Fe3O4. GO flakes were processed to have diameter mean size of 260 nm optimal for cellular internalization and conjugated to Fe3O4 NPs.

For the specific application of magnetic resonance imaging, the quality of an MRI contrast agent is often evaluated by the relaxivity parameters r1 or r2, which describe the ability of a contrast agent to shorten the T1 or T2 relaxation time of water. GO-Fe3O4 showed suitable for MRI imaging relaxivity values (longitudinal r1 and transvers r2 in water at 37°C), of r1=6.6 mM-1s-1 and r2=71.1 mM-1s-1. In fact, these values are better than those for single Fe3O4 NPs: the conjugated samples showed relaxivity ratio r2/r1>2, placing them in the category of negative contrast agent. The cytotoxicity of GO-Fe3O4 established via MTT assay in HeLa cells showed over 80% viability at the imaging concentrations mimicking that of GO. Cellular uptake and imaging studies show stable internalization and localized emission inside the cells. Additionally this system provides an efficient route to pH sensing of cellular environment as spectra of in GO-Fe3O4 are highly dependent on the pH of the media. This allows to assed the presence of acidic cancerous environments for cancer therapy and detection.

As a result, we propose that this new multifunctional GO-Fe3O4 composite can be used as a magnetic targeted drug delivery system, as well as biosensing and bimodal (MRI and fluorescence) imaging agent.
(Invited) New Concepts in Biosensing Using Single Walled Carbon Nanotubes and Graphene
Authors: Strano Michael S
Published: February 2020

Our lab at MIT has been interested in how the 1D and 2D electronic structures of carbon nanotubes and graphene respectively can be utilized to advance new concepts in molecular detection. We introduce CoPhMoRe or corona phase molecular recognition1 as a method of discovering synthetic antibodies, or nanotube-templated recognition sites from a heteropolymer library. We show that certain synthetic heteropolymers, once constrained onto a single-walled carbon nanotube by chemical adsorption, also form a new corona phase that exhibits highly selective recognition for speciﬁc molecules. To prove the generality of this phenomenon, we report three examples of heteropolymers–nanotube recognition complexes for riboﬂavin, L-thyroxine and estradiol. The platform opens new opportunities to create synthetic recognition sites for molecular detection. We have also extended this molecular recognition technique to neurotransmitters, producing the first fluorescent sensor for dopamine. Another area of advancement in biosensor development is the use of near infrared fluorescent carbon nanotube sensors for in-vivo detection2. Here, we show that PEG-ligated d(AAAT)7 DNA wrapped SWNT are selective for nitric oxide, a vasodilator of blood vessels, and can be tail vein injected into mice and localized within the viable mouse liver. We use an SJL mouse model to study liver inflammation in vivo using the spatially and spectrally resolved nIR signature of the localized SWNT sensors. Lastly, we discuss graphene as an interfacial optical biosensor, showing that it possesses two pKa values in alkaline and basic ranges. We use this response to measure dopamine in real time, spatially resolved at the interface with living PC12 cells which efflux dopamine, indicating graphene’s promise as an interfacial sensor in biology.

Zhang, JQ et. al. Molecular recognition using corona phase complexes made of synthetic polymers adsorbed on carbon nanotubes. Nature Nanotechnology, 8, 12, 2013, 959-968

Iverson, NM, et. al. In vivo biosensing via tissue-localizable near-infrared-fluorescent single-walled carbon nanotubes. Nature Nanotechnology, 8, 11, 2013, 873-880
Optical Properties of Dyes Confined into Carbon and Boron Nitride Nanotubes for Multimodal Bio-Imaging
Authors: Gaufres Etienne , Allard Charlotte , Nascimento Rafaella Oliveira , Fossard Frederic , Flahaut Emmanuel , Loiseau Annick , Martel Richard
Published: February 2020

Nanotubes attracted a lot of interest as 1D nano-porous materials for the encapsulation and aggregation control of organic dyes molecules. Indeed, the 1D confinement drives the stacking of the molecules inside and enables original aggregation effects on their optical properties (1,2). When encapsulated inside carbon nanotube, organics dyes such as 6T, exhibits for example a strong and specific Raman scattering but their luminescence is efficiently quenched by the nanotube (3). Here we show that the same dyes, when encapsulated inside boron nitride nanotubes (6T@BNNT) exhibits strong luminescence (4). Photoluminescence imaging experiments on individualized 6T@BNNT show that the encapsulation also circumvent the photobleaching issue over days under continuous photo-excitation. Finally we show that these hybrid materials, with specific luminescence and/or Raman fingerprints, can act as robust nanoprobes with reduced toxicity in living system such as Daphnia Pulex, for multimodal imaging from the visible to the near infrared range. (4)

(1) E. Gaufrès et al Nature Photon. (2014)

(2) S. Cambré et al Nature Nano (2015)

(3) E. Gaufrès et al ACS Nano (2016)

(4) E. Gaufrès et al (submitted)
Characterization of Double-Stranded DNA (dsDNA) on Single-Walled Carbon Nanotubes (SWCNTs)
Authors: Wu Shang-Jung , Schuergers Nils , Gillen Alice Judith , Boghossian Ardemis Anoush
Published: February 2020

DNA has been extensively studied due to its versatility as a dispersant of SWCNTs. The specificity and binding affinity of DNA to various analytes has been shown to be strongly sequence dependent. As a result, through modifications of the nucleotide sequence, the DNA conformation on the SWCNT surface can be tailored to suit specific needs for techniques such as single-molecule detection, in vivo imaging, and chirality separation. To date, the majority of research has focused on the interaction between single-stranded DNA and SWCNT surface, with less focus on the nature of the interaction between double-stranded DNA (dsDNA) and SWCNTs. As a result, the exact interaction mechanism governing this type of complex remains strongly debated and largely unknown.

In this study, we employ various biochemical methods to infer the conformation of dsDNA on the surface of SWCNTs. Our methods are based on imaging techniques for identifying DNA-modifying enzyme activity in the presence of dsDNA-SWCNT complexes. Our findings suggest that dsDNA can partially retain its native conformation on the SWCNT surface, and the degree of dsDNA accessibility is strongly sequence dependent. These findings offer new possibilities for SWCNT sensing applications that employ dsDNA, such as the optical detection of DNA-protein interactions.
(Invited) Nanocarbons for Multimodal Imaging, and Combination Multidrug/Gene Delivery
Authors: Naumov Anton V , Hasan Md Tanvir , Sizemore Elizabeth , Gonzalez-Rodriguez Roberto , Akkaraju Giridhar
Published: February 2020

Carbon nanomaterials including single-walled carbon nanotubes (SWCNTs) and graphene derivatives serve as a basis of multiple molecular imaging and biological sensing device applications. However, those applications are still mainly centered on a single analyte sensing or the delivery of one particular therapeutic. Structure-dependent band gap configuration of SWCNTs was shown and that of graphene derivatives provides a promise of multiwavelength imaging in near-infrared or visible spectral regions. We utilize these structural characteristics of nanocarbons to provide multidrug delivery and/or multicolor imaging for complex medical conditions requiring combination therapies such as nonalcoholic steatohepatitis (NASH). It is so far, a non-curable condition present in 6-8% of adults in the US. The progression of NASH is mediated mainly via fibrosis and inflammation interlinked through the production of cytokines. The treatment of this complex condition requires targeting of several factors at once. We utilize (6,5) and (7,5) SWCNT samples chirality-separated by aqueous two-phase extraction for the delivery and drug-specific in-vitro imaging of drug and gene therapeutics targeting inflammation and fibrosis. These active agents, each bound non-covalently to SWCNT sample enriched in a specific chirality and purified from the sorting surfactants, are delivered to HepG2 cells and imaged via characteristic SWCNT emission in the near-IR. Hyperspectral microscopy imaging at select wavelengths corresponding to resonant transitions of (6,5) and (7,5) SWCNTs allows to preferentially track the presence of SWCNTs bound to each specific therapeutic. Furthermore, therapeutic effects of each formulation are assessed separately via protein and cytotoxicity assays allowing to utilize remarkable properties of SWCNTs for multimodal imaging and multidrug/gene delivery for NASH therapeutics.

In addition to selective imaging by different SWCNT chiralities we explore multiwavelength biological imaging from the same nanomaterial produced through synthetic modification of nanoscale graphene derivatives and yielding dual-color green/near-IR emission. These fully biocompatible nanocarbons provide efficient internalization and in-vitro imaging in green (530 nm) with higher quantum yields and in near-IR (850 nm) water window region with decreased biological autofluorescence more optimal for ex-vivo and some in-vivo studies. Such new nanocarbon materials build a basis of multipurpose in-vitro/in-vivo multifunctional imaging/delivery agents.
Carbon Nanotubes as Nanovectors for Intracellular Delivery
Authors: DaRos Tatiana
Published: February 2020

Carbon nanostructures (CNSs) can be efficiently up-taken by cells and this allowed their use as vectors. So with an opportune functionalization it is possible to immobilized on CNSs various compounds, from small molecules till proteins and oligonucleotides, and efficiently deliver those units into cells. The presence of CNSs can ameliorate the efficiency of the uptake, and at the same time can also contribute to protect the delivered molecules from degradation.

We will explore some examples of effective use of CNSs for this purpouse.
(Invited) Assets of Nanodiamonds for Bioapplications
Authors: Arnault Jean-Charles
Published: February 2020

Diamond nanoparticles (nanodiamonds, NDs) behave physical and chemical properties expected from bulk diamond. Among these assets, their biocompatibility and their versatile surface chemistry based on carbon make them good candidates for bioapplications [1]. Moreover, the high surface to volume ratio of NDs can be tuned with sizes down to 5 nm depending on their synthesis methods [2]. This nanoscale confers new properties to NDs, often governed by their surface chemistry. This small primary size could also ensure a better elimination for in vivo studies. Lastly, the presence of color centers (NV, SiV) in the diamond lattice allow to use fluorescent NDs as biomarkers [3].

After providing the state of art of the synthesis and the current main applications of NDs, this talk will focus on the intrinsic properties of hydrogenated detonation NDs, from surface chemistry to colloidal behavior in water suspensions. Two hydrogenation methods will be compared in terms of hydrogen grafted or incorporated into NDs via isotope studies (3H) [4]. The hydrogenated NDs revealed an ability to produce reactive oxygen species (ROS) in radioresistant human cancer cells under gamma irradiation. This radiosensitive behavior was in vitro demonstrated, turning these cells into senescence state [5]. The physical and chemical mechanisms involved in the production of radicals were investigated by illuminating aqueous colloids of hydrogenated nanodiamonds under X-rays and gamma-rays. An overproduction of hydroxyl radicals and solvated electrons versus water radiolysis was measured using the 7-OH-coumarin as a fluorescent probe [6]. These results well evidence that NDs can act as active nanoparticles under illumination. The main perspectives of NDs for bioapplications will be discussed.

References

[1] K. Turcheniuk and V. N. Mochalin, Biomedical applications of nanodiamond, Nanotechnology 28 (2017) 252001.

[2] O. A. Shenderova, N. Nunn, Production and purification of nanodiamonds in: Nanodiamonds Advanced Material Analysis, Properties and Applications, J. C. Arnault Ed. (Elsevier (2017) pp 25-56.

[3] Y. Y. Hui, L. J. Su, O. Y. Chen, Y. T. Chen, T. M. Liu, H. C. Chang, Wide-field imaging and flow cytometric analysis of cancer cells in blood by fluorescent nanodiamond labeling and time gating, Scientific Reports 4 (2014) 5574.

[4] H.A. Girard, A. El Kharbachi, S. Garcia-Argote, T. Petit, P. Bergonzo, B. Rousseau, J.C. Arnault, Tritium labeling of detonation nanodiamonds. Chem. Comm. 50 (2014) 2916–2918.

[5] R. Grall, H. A. Girard, L. Saad, T. Petit, C. Gesset, M. Combis-Schlumberger, V. Paget, J. Delic, J. C. Arnault, S. Chevillard, Impairing the radioresistance of cancer cells by hydrogenated Nanodiamonds, Biomaterials 61 (2015) 290-298.

[6] M. Kurzyp, H. A. Girard, Y. Cheref, E. Brun, C. Sicard-Roselli, S. Saada, J. C. Arnault, Chem. Commun., 53 (2017) 1237.
PET Imaging of Tumor Uptake of a Biocompatible C60 Fullerene Drug Delivery Vector
Authors: Zaibaq Nicholas G. , Collins Michael J. , Pagel Mark D. , Wilson Lon J.
Published: February 2020

Traditional chemotherapy is one of the standards in cancer treatment, but the delivery of drugs and biologics is hindered by various barriers throughout the cancer microenvironment. Recently, nanoparticles have been of great interest as drug vectors because they can be tailored for specific functions to increase the amount of administered drug in the tumor microenvironment. In particular, biocompatible C60 fullerene has potential as a drug delivery scaffold since it has been shown to penetrate very restrictive physiological membranes (e.g. blood-brain-barrier and nuclear membrane)1. Our long-term goal is to determine the biodistribution of a biocompatible C60 material, as well as other pharmacokinetic data in both small and large animal models in order to evaluate its potential as a clinical drug vector for anti-cancer drugs. In this work, we have synthesized a C60 derivative with a metal chelating agent covalently bound to the C60 cage. The chelating agent of this material can be easily radiolabeled with 64Cu2+ (β+ emitter; t1/2 = 12 h) and tracked in vivo using positron emission tomography (PET) imaging. Because of its extreme sensitivity and routine clinical use, PET is an ideal imaging technique for studying pharmacokinetic properties and tumor accumulation of a C60 fullerene delivery vector, for both preclinical and possible future clinical studies. The material has been synthesized following an optimized six-step synthesis and the stability of the 64Cu2+ ion in the chelate has been evaluated by challenge with biological media. Animal biodistribution data will be determined using PET imaging in tumor- and non-tumor-bearing murine models.

Acknowledgements:

We gratefully acknowledge The Welch Foundation (C-0627) for support of this work, as well as the Department of Chemistry and the Smalley-Curl Institute at Rice University and the Department of Cancer Systems Imaging at UT MD Anderson Cancer Center. Additionally, the work is supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. 1450681 (N.G.Z.).

References:

(1) Raoof, M.; Mackeyev, Y.; Cheney, M. A.; Wilson, L. J.; Curley, S. A. Biomaterials
2012, 33 (10), 2952–2960.
(Invited) Molecular Requirement for Compounds Toward Facile Isolation of Adsorbent-Free Semiconducting Single-Walled Carbon Nanotubes Based on Supramolecular Chemistry
Authors: Toshimitsu Fumiyuki , Staykov Aleksandar , Nakashima Naotoshi
Published: February 2020

The separation/purification of semiconducting single-walled carbon nanotubes (sem-SWNTs) with high quality is one of the most important issues in the science and technology of carbon nanotubes[1-5]. We have already reported that supramolecular coordination polymer and hydrogen bonding systems as well as use of flavin molecules are powerful methods for highly efficient adsorbent-free sem-SWNT separation.

Here, we describe a molecular requirement of flavins (Bitamin B2 analogs)/isoallozadines for facile isolation of adsorbent-free sem-SWNTs based on supramolecular chemistry. Together with experimental results and molecular mechanics and molecular dynamics simulations, we will report a computer simulation study on this separation.

References

[1] F. Toshimitsu, N. Nakashima, Nature Communications, 2014, 5, art no. 5041.

[2] F. Toshimitsu, N. Nakashima, Sci. Rep., 2015, 5, art. no.18066.

[3] F. Toshimitsu, N. Nakashima, Chem. Eur. J., 2015, 21, 3359-3366.

[4] K. Akazaki, F. Toshimitsu, H. Ozawa, T. Fujigaya, N. Nakashima, J. Am. Chem. Soc. 2012, 134, 12700-12707.

[5] H. Ozawa, X. Yi, T. Fujigaya, Y. Niidome, T. Asano and N. Nakashima, J. Am. Chem. Soc., 2011, 133, 14771–14777.
Influence of Carbon Nanotube Chirality on Sodium Cholate Adsorption in Aqueous Suspensions
Authors: Schoeppler Friedrich , Vollert Ivonne , Bergler Felix , Hertel Tobias
Published: February 2020

Established chirality separation techniques for single-wall carbon nanotubes (SWNTs) in aqueous suspensions make use of chirality specific adsorption behavior of surfactants on these nano-carbon surfaces. Here, we investigate the adsorption of sodium cholate on SWNTs of different chirality with diameters ranging from 0.7 to 1 nm. Titration studies are performed at different temperatures by measuring photoluminescence emission energies of the diluted SWNT suspensions. The high sensitivity of the exciton to its environment allows to detect small changes in arrangement and concentration of surfactants on the SWNT surface, as recently shown for the (6,5) chirality by Bergler et al. [1]. Here we report on substrate-induced cooperative adsorption regimes for sodium cholate on five different SWNT chiralities. The critical micelle concentrations of the cholate-SWNT micelles exhibit a linear increase with SWNT diameter, while the thermodynamic stability of the cholate-SWNT micelles decreases. These diameter and temperature dependences may play a key role in the separation of SWNT chiralities by density gradient ultracentrifugation and aqueous two phase extraction and thus may help not only to understand the microscopic sorting mechanisms but also to improve empirical preparation protocols.

[1] Bergler et al., Langmuir 2016, 32, 9598-9603, DOI: 10.1021/acs.langmuir.6b02759