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Graphene has numerous potential applications in ultrathin electronics. There an electrode should function in contact with fluids and under mechanical stress; therefore, its stability is specifically of concern. Here, we explored a custom-made quartz crystal microbalance (QCM) sensor covered with wet-transferred large-scale monolayer graphene for investigation of an electrode behavior. Monolayer graphene was found to be stable on an oscillating substrate in contact with air and liquid. Under the liquid flow and simultaneously applied electrochemical potential, we managed to induce graphene oxidation, impact of which was observed on a quartz crystal microbalance monitoring and Raman spectra. Applied potentials of 1 V and higher (vs. Ag/AgCl reference electrode) caused graphene oxidation which led to loss of the layer integrity and erosion of the material. Graphic abstract
Anastasia Svetlova; Guillermo Beltramo; Dmitry Kireev; Andreas Offenhäusser. Quartz crystal microbalance monitoring of large-area graphene anodization reveals layer fracturing. MRS Advances 2021, 6, 270 -275.
AMA StyleAnastasia Svetlova, Guillermo Beltramo, Dmitry Kireev, Andreas Offenhäusser. Quartz crystal microbalance monitoring of large-area graphene anodization reveals layer fracturing. MRS Advances. 2021; 6 (10):270-275.
Chicago/Turabian StyleAnastasia Svetlova; Guillermo Beltramo; Dmitry Kireev; Andreas Offenhäusser. 2021. "Quartz crystal microbalance monitoring of large-area graphene anodization reveals layer fracturing." MRS Advances 6, no. 10: 270-275.
Numerous fields of science and technology, including healthcare, robotics and bioelectronics, have begun to switch their research direction from developing ‘high-end, high-cost’ tools towards ‘high-end, low-cost’ solutions. Graphene electronic tattoos (GETs), whose fabrication protocol is discussed in this work, are ideal building blocks of future wearable technology due to their outstanding electromechanical properties. The GETs are composed of high-quality, large-scale graphene that is transferred onto tattoo paper, resulting in an electronic device that is applied onto skin like a temporary tattoo. Here, we provide a comprehensive GET fabrication protocol, starting from graphene growth and ending with integration onto human skin. The methodology presented is unique since it utilizes high-quality electronic-grade graphene, while the processing is done by using low-cost and off-the-shelf methods, such as a mechanical cutter plotter. The GETs can be either used in combination with advanced scientific equipment to perform precision experiments, or with low-cost electrophysiology boards, to conduct similar operations from home. In this protocol, we showcase how GETs can be applied onto the human body and how they can be used to obtain a variety of biopotentials, including electroencephalogram (brain waves), electrocardiogram (heart activity), electromyogram (muscle activity), as well as monitoring of body temperature and hydration. With graphene available from commercial sources, the whole protocol consumes ~3 h of labor and does not require highly trained personnel. The protocol described in this work can be readily replicated in simple laboratories, including high school facilities. This protocol describes how to fabricate graphene electronic tattoos (GETs) that offer unique electromechanical properties. The GETs can be used for a variety of applications, including wearables, personalized biosensors and human–computer interfaces.
Dmitry Kireev; Shideh Kabiri Ameri; Alena Nederveld; Jameson Kampfe; Hongwoo Jang; Nanshu Lu; Deji Akinwande. Fabrication, characterization and applications of graphene electronic tattoos. Nature Protocols 2021, 16, 2395 -2417.
AMA StyleDmitry Kireev, Shideh Kabiri Ameri, Alena Nederveld, Jameson Kampfe, Hongwoo Jang, Nanshu Lu, Deji Akinwande. Fabrication, characterization and applications of graphene electronic tattoos. Nature Protocols. 2021; 16 (5):2395-2417.
Chicago/Turabian StyleDmitry Kireev; Shideh Kabiri Ameri; Alena Nederveld; Jameson Kampfe; Hongwoo Jang; Nanshu Lu; Deji Akinwande. 2021. "Fabrication, characterization and applications of graphene electronic tattoos." Nature Protocols 16, no. 5: 2395-2417.
Wearable bioelectronics with emphasis on the research and development of advanced person-oriented biomedical devices have attracted immense interest in the past decade. Scientists and clinicians find it essential to utilize skin-worn smart tattoos for on-demand and ambulatory monitoring of an individual’s vital signs. Here, we report on the development of ultrathin platinum-based two-dimensional dichalcogenide (Pt-TMDs)-based electronic tattoos as advanced building blocks of future wearable bioelectronics. We made these ultrathin electronic tattoos out of large-scale synthesized platinum diselenide (PtSe2) and platinum ditelluride (PtTe2) layered materials and used them for monitoring human physiological vital signs, such as the electrical activity of the heart and the brain, muscle contractions, eye movements, and temperature. We show that both materials can be used for these applications; yet, PtTe2 was found to be the most suitable choice due to its metallic structure. In terms of sheet resistance, skin contact, and electrochemical impedance, PtTe2 outperforms state-of-the-art gold and graphene electronic tattoos and performs on par with medical-grade Ag/AgCl gel electrodes. The PtTe2 tattoos show 4 times lower impedance and almost 100 times lower sheet resistance compared to monolayer graphene tattoos. One of the possible prompt implications of this work is perhaps in the development of advanced human–machine interfaces. To display the application, we built a multi-tattoo system that can easily distinguish eye movement and identify the direction of an individual’s sight.
Dmitry Kireev; Emmanuel Okogbue; Rt Jayanth; Tae-Jun Ko; Yeonwoong Jung; Deji Akinwande. Multipurpose and Reusable Ultrathin Electronic Tattoos Based on PtSe2 and PtTe2. ACS Nano 2021, 15, 2800 -2811.
AMA StyleDmitry Kireev, Emmanuel Okogbue, Rt Jayanth, Tae-Jun Ko, Yeonwoong Jung, Deji Akinwande. Multipurpose and Reusable Ultrathin Electronic Tattoos Based on PtSe2 and PtTe2. ACS Nano. 2021; 15 (2):2800-2811.
Chicago/Turabian StyleDmitry Kireev; Emmanuel Okogbue; Rt Jayanth; Tae-Jun Ko; Yeonwoong Jung; Deji Akinwande. 2021. "Multipurpose and Reusable Ultrathin Electronic Tattoos Based on PtSe2 and PtTe2." ACS Nano 15, no. 2: 2800-2811.
Iron deficiency (ID) is the most prevalent and severe nutritional disorder globally and is the leading cause of iron deficiency anemia (IDA). IDA often progresses subtly symptomatic in children, whereas prolonged deficiency may permanently impair development. Early detection and frequent screening are, therefore, essential to avoid the consequences of IDA. In order to reduce the production cost and complexities involved in building advanced ID sensors, the devices were fabricated using a home-built patterning procedure that was developed and used for this work instead of lithography, which allows for fast prototyping of dimensions. In this article, we report the development of graphene-based field-effect transistors (GFETs) functionalized with anti-ferritin antibodies through a linker molecule (1-pyrenebutanoic acid, succinimidyl ester), to facilitate specific conjugation with ferritin antigen. The resulting biosensors feature an unprecedented ferritin detection limit of 10 fM, indicating a tremendous potential for non-invasive (e.g., saliva) ferritin detection.
Oluwadamilola Oshin; Dmitry Kireev; Hanna Hlukhova; Francis Idachaba; Deji Akinwande; Aderemi Atayero. Graphene-Based Biosensor for Early Detection of Iron Deficiency. Sensors 2020, 20, 3688 .
AMA StyleOluwadamilola Oshin, Dmitry Kireev, Hanna Hlukhova, Francis Idachaba, Deji Akinwande, Aderemi Atayero. Graphene-Based Biosensor for Early Detection of Iron Deficiency. Sensors. 2020; 20 (13):3688.
Chicago/Turabian StyleOluwadamilola Oshin; Dmitry Kireev; Hanna Hlukhova; Francis Idachaba; Deji Akinwande; Aderemi Atayero. 2020. "Graphene-Based Biosensor for Early Detection of Iron Deficiency." Sensors 20, no. 13: 3688.
Oluwadamilola Oshin; Dmitry Kireev; Deji Akinwande; Emmanuel Adetiba; Francis Idachaba; Aderemi Atayero. Advancing PoC Devices for Early Disease Detection using Graphene-based Sensors. Journal of Physics: Conference Series 2019, 1378, 1 .
AMA StyleOluwadamilola Oshin, Dmitry Kireev, Deji Akinwande, Emmanuel Adetiba, Francis Idachaba, Aderemi Atayero. Advancing PoC Devices for Early Disease Detection using Graphene-based Sensors. Journal of Physics: Conference Series. 2019; 1378 ():1.
Chicago/Turabian StyleOluwadamilola Oshin; Dmitry Kireev; Deji Akinwande; Emmanuel Adetiba; Francis Idachaba; Aderemi Atayero. 2019. "Advancing PoC Devices for Early Disease Detection using Graphene-based Sensors." Journal of Physics: Conference Series 1378, no. : 1.
In this work, we report a novel method of maskless doping of a graphene channel in a field-effect transistor configuration by local inkjet printing of organic semiconducting molecules. The graphene-based transistor was fabricated via large-scale technology, allowing for upscaling electronic device fabrication and lowering the device’s cost. The altering of the functionalization of graphene was performed through local inkjet printing of N,N′-Dihexyl-3,4,9,10-perylenedicarboximide (PDI-C6) semiconducting molecules’ ink. We demonstrated the high resolution (about 50 µm) and accurate printing of organic ink on bare chemical vapor deposited (CVD) graphene. PDI-C6 forms nanocrystals onto the graphene’s surface and transfers charges via π–π stacking to graphene. While the doping from organic molecules was compensated by oxygen molecules under normal conditions, we demonstrated the photoinduced current generation at the PDI-C6/graphene junction with ambient light, a 470 nm diode, and 532 nm laser sources. The local (in the scale of 1 µm) photoresponse of 0.5 A/W was demonstrated at a low laser power density. The methods we developed open the way for local functionalization of an on-chip array of graphene by inkjet printing of different semiconducting organic molecules for photonics and electronics.
Nikita Nekrasov; Dmitry Kireev; Nejra Omerović; Aleksei Emelianov; Ivan Bobrinetskiy. Photo-Induced Doping in a Graphene Field-Effect Transistor with Inkjet-Printed Organic Semiconducting Molecules. Nanomaterials 2019, 9, 1753 .
AMA StyleNikita Nekrasov, Dmitry Kireev, Nejra Omerović, Aleksei Emelianov, Ivan Bobrinetskiy. Photo-Induced Doping in a Graphene Field-Effect Transistor with Inkjet-Printed Organic Semiconducting Molecules. Nanomaterials. 2019; 9 (12):1753.
Chicago/Turabian StyleNikita Nekrasov; Dmitry Kireev; Nejra Omerović; Aleksei Emelianov; Ivan Bobrinetskiy. 2019. "Photo-Induced Doping in a Graphene Field-Effect Transistor with Inkjet-Printed Organic Semiconducting Molecules." Nanomaterials 9, no. 12: 1753.
Micro-electrode arrays are widely used in such different fields such as neurobiology or biomedicine to read out electrical signals from cells or biomolecules. One way to improve micro-electrode applications is the development of novel electrode materials with enhanced or additional functionality. In this study, we fabricated macro-electrodes and micro-electrode arrays containing gold penetrated by nanohole arrays as a conductive layer. We used this holey gold to optically excite surface plasmon polaritons which lead to a strong increase in transparency, an effect that is further enhanced by the plasmon’s interaction with cell culture medium. Further, we demonstrate that the novel transparent micro-electrode arrays are as suitable for recording cellular electrical activity as standard devices. Moreover, we prove using spectral measurements and finite difference time domain simulations that plasmonically induced transmission peaks of holey gold redshift upon sensing medium or cells in close vicinity (<30 nm) to the substrate. Thus, we establish plasmonic and transparent holey gold as a material suitable for cellular electrical recordings and biosensing applications.
Timm J. J. Hondrich; Bohdan Lenyk; Pegah Shokoohimehr; Dmitry Kireev; Vanessa Maybeck; Dirk Mayer; Andreas Offenhäusser. MEA Recordings and Cell–Substrate Investigations with Plasmonic and Transparent, Tunable Holey Gold. ACS Applied Materials & Interfaces 2019, 11, 46451 -46461.
AMA StyleTimm J. J. Hondrich, Bohdan Lenyk, Pegah Shokoohimehr, Dmitry Kireev, Vanessa Maybeck, Dirk Mayer, Andreas Offenhäusser. MEA Recordings and Cell–Substrate Investigations with Plasmonic and Transparent, Tunable Holey Gold. ACS Applied Materials & Interfaces. 2019; 11 (50):46451-46461.
Chicago/Turabian StyleTimm J. J. Hondrich; Bohdan Lenyk; Pegah Shokoohimehr; Dmitry Kireev; Vanessa Maybeck; Dirk Mayer; Andreas Offenhäusser. 2019. "MEA Recordings and Cell–Substrate Investigations with Plasmonic and Transparent, Tunable Holey Gold." ACS Applied Materials & Interfaces 11, no. 50: 46451-46461.
Graphene coated with nanoparticles has been used to make wearable light sensors that measure the human pulse and blood oxygen levels from ambient light passing through tissue, offering a potential platform for health-care monitoring. Flexible photosensors based on graphene coated with quantum dots.
Deji Akinwande; Dmitry Kireev. Wearable graphene sensors use ambient light to monitor health. Nature 2019, 576, 220 -221.
AMA StyleDeji Akinwande, Dmitry Kireev. Wearable graphene sensors use ambient light to monitor health. Nature. 2019; 576 (7786):220-221.
Chicago/Turabian StyleDeji Akinwande; Dmitry Kireev. 2019. "Wearable graphene sensors use ambient light to monitor health." Nature 576, no. 7786: 220-221.
This review provides a critical overview of current developments on nanoelectronic biochemical sensors based on graphene. Composed of a single layer of conjugated carbon atoms, graphene has outstanding high carrier mobility and low intrinsic electrical noise, but a chemically inert surface. Surface functionalization is therefore crucial to unravel graphene sensitivity and selectivity for the detection of targeted analytes. To achieve optimal performance of graphene transistors for biochemical sensing, the tuning of the graphene surface properties via surface functionalization and passivation is highlighted, as well as the tuning of its electrical operation by utilizing multifrequency ambipolar configuration and a high frequency measurement scheme to overcome the Debye screening to achieve low noise and highly sensitive detection. Potential applications and prospectives of ultrasensitive graphene electronic biochemical sensors ranging from environmental monitoring and food safety, healthcare and medical diagnosis, to life science research, are presented as well.
Xiaoyan Zhang; Qiushi Jing; Shen Ao; Grégory F. Schneider; Dmitry Kireev; Zhengjun Zhang; Wangyang Fu. Ultrasensitive Field‐Effect Biosensors Enabled by the Unique Electronic Properties of Graphene. Small 2019, 16, e1902820 .
AMA StyleXiaoyan Zhang, Qiushi Jing, Shen Ao, Grégory F. Schneider, Dmitry Kireev, Zhengjun Zhang, Wangyang Fu. Ultrasensitive Field‐Effect Biosensors Enabled by the Unique Electronic Properties of Graphene. Small. 2019; 16 (15):e1902820.
Chicago/Turabian StyleXiaoyan Zhang; Qiushi Jing; Shen Ao; Grégory F. Schneider; Dmitry Kireev; Zhengjun Zhang; Wangyang Fu. 2019. "Ultrasensitive Field‐Effect Biosensors Enabled by the Unique Electronic Properties of Graphene." Small 16, no. 15: e1902820.
I. Protsenko; A. Barannik; N. Cherpak; A. Gubin; Dmitry Kireev; Svetlana Vitusevich. WGM Resonators for Conductivity Measurements of Graphene Films. 2019 49th European Microwave Conference (EuMC) 2019, 1 .
AMA StyleI. Protsenko, A. Barannik, N. Cherpak, A. Gubin, Dmitry Kireev, Svetlana Vitusevich. WGM Resonators for Conductivity Measurements of Graphene Films. 2019 49th European Microwave Conference (EuMC). 2019; ():1.
Chicago/Turabian StyleI. Protsenko; A. Barannik; N. Cherpak; A. Gubin; Dmitry Kireev; Svetlana Vitusevich. 2019. "WGM Resonators for Conductivity Measurements of Graphene Films." 2019 49th European Microwave Conference (EuMC) , no. : 1.
Kaan Sel; Dmitry Kireev; Alexander Brown; Bassem Ibrahim; Deji Akinwande; Roozbeh Jafari. Electrical Characterization of Graphene-based e-Tattoos for Bio-Impedance-based Physiological Sensing. 2019 IEEE Biomedical Circuits and Systems Conference (BioCAS) 2019, 1 .
AMA StyleKaan Sel, Dmitry Kireev, Alexander Brown, Bassem Ibrahim, Deji Akinwande, Roozbeh Jafari. Electrical Characterization of Graphene-based e-Tattoos for Bio-Impedance-based Physiological Sensing. 2019 IEEE Biomedical Circuits and Systems Conference (BioCAS). 2019; ():1.
Chicago/Turabian StyleKaan Sel; Dmitry Kireev; Alexander Brown; Bassem Ibrahim; Deji Akinwande; Roozbeh Jafari. 2019. "Electrical Characterization of Graphene-based e-Tattoos for Bio-Impedance-based Physiological Sensing." 2019 IEEE Biomedical Circuits and Systems Conference (BioCAS) , no. : 1.
In this work, we report an on-chip aptasensor for ochratoxin A (OTA) toxin detection that is based on a graphene field-effect transistor (GFET). Graphene-based devices are fabricated via large-scale technology, allowing for upscaling the sensor fabrication and lowering the device cost. The sensor assembly was performed through covalent bonding of graphene’s surface with an aptamer specifically sensitive towards OTA. The results demonstrate fast (within 5 min) response to OTA exposure with a linear range of detection between 4 ng/mL and 10 pg/mL, with a detection limit of 4 pg/mL. The regeneration time constant of the sensor was found to be rather small, only 5.6 s, meaning fast sensor regeneration for multiple usages. The high reproducibility of the sensing response was demonstrated via using several recycling procedures as well as various GFETs. The applicability of the aptasensor to real samples was demonstrated for spiked red wine samples with recovery of about 105% for a 100 pM OTA concentration; the selectivity of the sensor was also confirmed via addition of another toxin, zearalenone. The developed platform opens the way for multiplex sensing of different toxins using an on-chip array of graphene sensors.
Nikita Nekrasov; Dmitry Kireev; Aleksei Emelianov; Ivan Bobrinetskiy. Graphene-Based Sensing Platform for On-Chip Ochratoxin A Detection. Toxins 2019, 11, 550 .
AMA StyleNikita Nekrasov, Dmitry Kireev, Aleksei Emelianov, Ivan Bobrinetskiy. Graphene-Based Sensing Platform for On-Chip Ochratoxin A Detection. Toxins. 2019; 11 (10):550.
Chicago/Turabian StyleNikita Nekrasov; Dmitry Kireev; Aleksei Emelianov; Ivan Bobrinetskiy. 2019. "Graphene-Based Sensing Platform for On-Chip Ochratoxin A Detection." Toxins 11, no. 10: 550.
In the current work, we introduce a brand new line of versatile, flexible, and multifunctional MEA probes, the so-called Nano Neuro Net, or N3-MEAs. Material choice, dimensions, and room for further upgrade, were carefully considered when designing such probes in order to cover the widest application range possible. Proof of the operation principle of these novel probes is shown in the manuscript via the recording of extracellular signals, such as action potentials and local field potentials from cardiac cells and retinal ganglion cells of the heart tissue and eye respectively. Reasonably large signal to noise ratio (SNR) combined with effortless operation of the devices, mechanical and chemical stability, multifunctionality provide, in our opinion, an unprecedented blend. We show successful recordings of (1) action potentials from heart tissue with a SNR up to 13.2; (2) spontaneous activity of retinal ganglion cells with a SNR up to 12.8; and (3) local field potentials with an ERG-like waveform, as well as spiking responses of the retina to light stimulation. The results reveal not only the multi-functionality of these N3-MEAs, but high quality recordings of electrogenic tissues.
Dmitry Kireev; Viviana Rincón Montes; Jelena Stevanovic; Kagithiri Srikantharajah; Andreas Offenhäusser. N3-MEA Probes: Scooping Neuronal Networks. Frontiers in Neuroscience 2019, 13, 320 .
AMA StyleDmitry Kireev, Viviana Rincón Montes, Jelena Stevanovic, Kagithiri Srikantharajah, Andreas Offenhäusser. N3-MEA Probes: Scooping Neuronal Networks. Frontiers in Neuroscience. 2019; 13 ():320.
Chicago/Turabian StyleDmitry Kireev; Viviana Rincón Montes; Jelena Stevanovic; Kagithiri Srikantharajah; Andreas Offenhäusser. 2019. "N3-MEA Probes: Scooping Neuronal Networks." Frontiers in Neuroscience 13, no. : 320.
The response of a sapphire whispering gallery mode (WGM) resonator to a single-layer graphene film was studied in the millimeter wave band (frequency of about 40 GHz) at different distances of graphene from the resonator. In the resonator, the HE141δ WGM was excited, in which the longitudinal component of the electric field is predominant. Based on the fitting results of both the response measurement and the numerical simulation of the resonator, the conductivity value was obtained for a known film thickness. The conductivity of our CVD-grown and transferred graphene was found to be (1.02 ± 0.06) × 106 S/m. This deviates slightly from the values obtained through our DC conductivity measurements, reflecting the real parameters of the graphene material after transfer from copper to a quartz substrate. A significant difference was demonstrated between the conductivity values obtained by the fitting procedure and those calculated using the perturbation method. In explanation for the discrepancy, we propose a possible inapplicability of the perturbation method for the cases of both the resonator and mode polarization used in this work. The results of this work show that a WGM resonator technique allows contactless exploration of graphene parameters, such as conductivity or sheet resistance, in the millimeter wave band.
A. A. Barannik; N. T. Cherpak; I. A. Protsenko; A. I. Gubin; D. Kireev; S. Vitusevich. Contactless exploration of graphene properties using millimeter wave response of WGM resonator. Applied Physics Letters 2018, 113, 094102 .
AMA StyleA. A. Barannik, N. T. Cherpak, I. A. Protsenko, A. I. Gubin, D. Kireev, S. Vitusevich. Contactless exploration of graphene properties using millimeter wave response of WGM resonator. Applied Physics Letters. 2018; 113 (9):094102.
Chicago/Turabian StyleA. A. Barannik; N. T. Cherpak; I. A. Protsenko; A. I. Gubin; D. Kireev; S. Vitusevich. 2018. "Contactless exploration of graphene properties using millimeter wave response of WGM resonator." Applied Physics Letters 113, no. 9: 094102.
Graphene bioelectronics is a groundbreaking field which emerged roughly eight years ago offering important opportunities for developing new kinds of sensors capable of establishing an outstanding interface with soft tissue. Graphene-based transistors, as well as electrode arrays, have emerged as a special group of biosensors with their own peculiarities, advantages and drawbacks. In this review, we show the progress of the field from single device measurements to in vivo neuroprosthetic devices. First, the general architectures of device fabrication and their implementation for extracellular recordings are discussed, along with the basic sensing mechanisms essential for their use as sensors. Then state-of-the-art approaches are introduced with a discussion of advantages and drawbacks in the design/measurement architectures. As a whole, the review highlights the results from the ever-growing discipline of graphene bioelectronics and also draws reasonable conclusions for future research directions. The possibility of using other device architectures or other two-dimensional materials such as MoS2 and MXenes for the same goal are assessed at the end of this review in order to highlight future challenges and directions towards an efficient 2D materials-to-brain interface.
Dmitry Kireev; Andreas Offenhaeusser. Graphene & two-dimensional devices for bioelectronics and neuroprosthetics. 2D Materials 2018, 5, 042004 .
AMA StyleDmitry Kireev, Andreas Offenhaeusser. Graphene & two-dimensional devices for bioelectronics and neuroprosthetics. 2D Materials. 2018; 5 (4):042004.
Chicago/Turabian StyleDmitry Kireev; Andreas Offenhaeusser. 2018. "Graphene & two-dimensional devices for bioelectronics and neuroprosthetics." 2D Materials 5, no. 4: 042004.
Flexible and transparent electronic devices possess crucial advantages over conventional silicon based systems for bioelectronic applications since they are able to adapt to nonplanar surfaces, cause less chronic immunoreactivity, and facilitate easy optical inspection. Here, organic electrochemical transistors (OECTs) are embedded in a flexible matrix of polyimide to record cardiac action potentials. The wafer‐scale fabricated devices exhibit transconductances (12 mS V−1) and drain–source on‐to‐off current ratios (≈105) comparable to state of the art nonflexible and superior to other reported flexible OECTs. The transfer characteristics of the devices are preserved even after experiencing extremely high bending strain and harsh crumpling. A sub‐micrometer poly(3,4‐ethylenedioxythiophene) doped with poly(styrenesulfonate) layer results in a fast transport of ions between the electrolyte and the polymer channel characterized by a cut‐off frequency of 1200 Hz. Excellent device performance is proved by mapping the propagation of cardiac action potentials with high signal‐to‐noise ratio. These results demonstrate that the electrical performance of flexible OECTs can compete with hard‐material‐based OECTs and thus potentially be used for in vivo applications.
Yuanying Liang; Mathis Ernst; Fabian Brings; Dmitry Kireev; Vanessa Maybeck; Andreas Offenhäusser; Dirk Mayer. High Performance Flexible Organic Electrochemical Transistors for Monitoring Cardiac Action Potential. Advanced Healthcare Materials 2018, 7, e1800304 .
AMA StyleYuanying Liang, Mathis Ernst, Fabian Brings, Dmitry Kireev, Vanessa Maybeck, Andreas Offenhäusser, Dirk Mayer. High Performance Flexible Organic Electrochemical Transistors for Monitoring Cardiac Action Potential. Advanced Healthcare Materials. 2018; 7 (19):e1800304.
Chicago/Turabian StyleYuanying Liang; Mathis Ernst; Fabian Brings; Dmitry Kireev; Vanessa Maybeck; Andreas Offenhäusser; Dirk Mayer. 2018. "High Performance Flexible Organic Electrochemical Transistors for Monitoring Cardiac Action Potential." Advanced Healthcare Materials 7, no. 19: e1800304.
Single and few-layer graphene photodetectors have attracted much attention in the past few years. Pristine graphene shows a very weak response to visible light, hence fabrication of complex graphene based detectors is a challenging task. In this work, we utilize the ultrafast laser functionalization of single-layer CVD graphene for highly desirable maskless fabrication of micro- and nanoscale devices. We investigate the optoelectronic response of pristine and functionalized devices under femtosecond and continuous wave lasers irradiation. We demonstrate that the photocurrent generation in p-p+ junctions formed in single layer graphene is related to the photo-thermoelectric effect. The photoresponsivity of our laser patterned single-layer graphene junctions is shown to be as high as 100 mA/W with noise equivalent power less than 6 kW/cm2. These results open a path to a low-cost maskless technology for fabrication of graphene based optoelectronic devices with tunable properties for spectroscopy, signal processing and other applications.
Aleksei V. Emelianov; Dmitry Kireev; Andreas Offenhäusser; Nerea Otero; Pablo M. Romero; Ivan I. Bobrinetskiy. Thermoelectrically Driven Photocurrent Generation in Femtosecond Laser Patterned Graphene Junctions. ACS Photonics 2018, 5, 3107 -3115.
AMA StyleAleksei V. Emelianov, Dmitry Kireev, Andreas Offenhäusser, Nerea Otero, Pablo M. Romero, Ivan I. Bobrinetskiy. Thermoelectrically Driven Photocurrent Generation in Femtosecond Laser Patterned Graphene Junctions. ACS Photonics. 2018; 5 (8):3107-3115.
Chicago/Turabian StyleAleksei V. Emelianov; Dmitry Kireev; Andreas Offenhäusser; Nerea Otero; Pablo M. Romero; Ivan I. Bobrinetskiy. 2018. "Thermoelectrically Driven Photocurrent Generation in Femtosecond Laser Patterned Graphene Junctions." ACS Photonics 5, no. 8: 3107-3115.
The development of planar functional junction provides continuous, single-atom thick, in-plane integrated circuits. The production of atomic contacts of different materials (hetero/homostructures) is still a challenging task for 2D materials technology. In this paper we describe a new method of formation of a photosensitive junction by femtosecond laser pulses patterning of graphene FET. The laser-induced oxidation of graphene goes under high intensity laser pulses, which provide nonlinear effects in graphene like multiphoton absorption and hot carrier generation. The process of laser induced local oxidation is studied on single-layer graphene FET produced by wet transfer of CVD grown graphene on copper foil onto a Si/SiO2 substrate. The 280 fs laser with 515 nm wavelength with various pulse energies is applied to modify of local electrical and optical properties of graphene. Thus, the developed process provides mask-less laser induced in-plane junction patterning in graphene. The scale of local heterojunction fabrication is about 1 μm. We observe that with an increasing of the laser fluence the number of defects increases according to two different mechanism for low and high fluences, respectively. The change of the charge carrier concentration causes the Dirac point shift in produced structures. We investigate the photoresponse in graphene junctions under fs pulsed laser irradiation with subthreshold energies. The response time is rather high while relaxation time is large because of charge traps at the graphene/SiO2 interface.
Ivan I. Bobrinetskiy; Aleksei Emelianov; Nerea Otero; Pablo Romero; Dmirty Kireev. Photosensitive in-plane junction in graphene field effect transistor modified under femtoseconds laser irradiation. Nanophotonics VII 2018, 10672, 106720A .
AMA StyleIvan I. Bobrinetskiy, Aleksei Emelianov, Nerea Otero, Pablo Romero, Dmirty Kireev. Photosensitive in-plane junction in graphene field effect transistor modified under femtoseconds laser irradiation. Nanophotonics VII. 2018; 10672 ():106720A.
Chicago/Turabian StyleIvan I. Bobrinetskiy; Aleksei Emelianov; Nerea Otero; Pablo Romero; Dmirty Kireev. 2018. "Photosensitive in-plane junction in graphene field effect transistor modified under femtoseconds laser irradiation." Nanophotonics VII 10672, no. : 106720A.
Graphene based devices have already proven to be extremely sensitive and very useful in a wide spectrum of bioelectronics research. In the manuscript we describe a method to fabricate arrays of graphene-based probes, requiring minimal number of fabrication steps, while maintaining overall device functionality. These polyimide-based probes are approximately 6 µm thick, therefore ultraflexible, yet robust and stable. Devices, such as graphene field effect transistors (GFETs) and graphene multielectrode arrays (GMEAs) have been designed, fabricated and tested for their performance. The flexible GFETs exhibit sensitivity, i.e. transconductance up to 700 µS/V, which an order of magnitude larger compared to typical silicon transistors. Multiple probe per wafer design allows us to fabricate different kinds of devices on one 4-inch wafer, consequently increasing a possible range of applications from e.g. retinal to cortical neuroprosthetics.
Dmitry Kireev; Pegah Shokoohimehr; Mathis Ernst; Viviana Rincón Montes; Kagithiri Srikantharajah; Vanessa Maybeck; Bernhard Wolfrum; Andreas Offenhäusser. Fabrication of ultrathin and flexible graphene-based devices for in vivo neuroprosthetics. MRS Advances 2018, 3, 1621 -1627.
AMA StyleDmitry Kireev, Pegah Shokoohimehr, Mathis Ernst, Viviana Rincón Montes, Kagithiri Srikantharajah, Vanessa Maybeck, Bernhard Wolfrum, Andreas Offenhäusser. Fabrication of ultrathin and flexible graphene-based devices for in vivo neuroprosthetics. MRS Advances. 2018; 3 (29):1621-1627.
Chicago/Turabian StyleDmitry Kireev; Pegah Shokoohimehr; Mathis Ernst; Viviana Rincón Montes; Kagithiri Srikantharajah; Vanessa Maybeck; Bernhard Wolfrum; Andreas Offenhäusser. 2018. "Fabrication of ultrathin and flexible graphene-based devices for in vivo neuroprosthetics." MRS Advances 3, no. 29: 1621-1627.
Over the past decade, the richness of electronic properties of graphene has attracted enormous interest for electrically detecting chemical and biological species using this two-dimensional material. However, the creation of practical graphene electronic sensors greatly depends on our ability to understand and maintain a low level of electronic noise, the fundamental reason limiting the sensor resolution. Conventionally, to reach the largest sensing response, graphene transistors are operated at the point of maximum transconductance, where 1/f noise is found to be unfavorably high and poses a major limitation in any attempt to further improve the device sensitivity. We show that operating a graphene transistor in an ambipolar mode near its neutrality point can markedly reduce the 1/f noise in graphene. Remarkably, our data reveal that this reduction in the electronic noise is achieved with uncompromised sensing response of the graphene chips and thus significantly improving the signal-to-noise ratio—compared to that of a conventionally operated graphene transistor for conductance measurement. As a proof-of-concept demonstration of the usage of the aforementioned new sensing scheme to a broader range of biochemical sensing applications, we selected an HIV-related DNA hybridization as the test bed and achieved detections at picomolar concentrations.
Wangyang Fu; Lingyan Feng; Gregory Panaitov; Dmitry Kireev; Dirk Mayer; Andreas Offenhäusser; Hans-Joachim Krause. Biosensing near the neutrality point of graphene. Science Advances 2017, 3, e1701247 -1701247.
AMA StyleWangyang Fu, Lingyan Feng, Gregory Panaitov, Dmitry Kireev, Dirk Mayer, Andreas Offenhäusser, Hans-Joachim Krause. Biosensing near the neutrality point of graphene. Science Advances. 2017; 3 (10):e1701247-1701247.
Chicago/Turabian StyleWangyang Fu; Lingyan Feng; Gregory Panaitov; Dmitry Kireev; Dirk Mayer; Andreas Offenhäusser; Hans-Joachim Krause. 2017. "Biosensing near the neutrality point of graphene." Science Advances 3, no. 10: e1701247-1701247.