1
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Bae G, Cho H, Hong BH. A review on synthesis, properties, and biomedical applications of graphene quantum dots (GQDs). NANOTECHNOLOGY 2024; 35:372001. [PMID: 38853586 DOI: 10.1088/1361-6528/ad55d0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 06/05/2024] [Indexed: 06/11/2024]
Abstract
A new type of 0-dimensional carbon-based materials called graphene quantum dots (GQDs) is gaining significant attention as a non-toxic and eco-friendly nanomaterial. GQDs are nanomaterials composed of sp2hybridized carbon domains and functional groups, with their lateral size less than 10 nm. The unique and exceptional physical, chemical, and optical properties arising from the combination of graphene structure and quantum confinement effect due to their nano-size make GQDs more intriguing than other nanomaterials. Particularly, the low toxicity and high solubility derived from the carbon core and abundant edge functional groups offer significant advantages for the application of GQDs in the biomedical field. In this review, we summarize various synthetic methods for preparing GQDs and important factors influencing the physical, chemical, optical, and biological properties of GQDs. Furthermore, the recent application of GQDs in the biomedical field, including biosensor, bioimaging, drug delivery, and therapeutics are discussed. Through this, we provide a brief insight on the tremendous potential of GQDs in biomedical applications and the challenges that need to be overcome in the future.
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Affiliation(s)
- Gaeun Bae
- Department of Chemistry, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Hyeonwoo Cho
- Department of Chemistry, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Byung Hee Hong
- Department of Chemistry, Seoul National University (SNU), Seoul 08826, Republic of Korea
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2
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Zhang C, Chen M, Pan Y, Li Y, Wang K, Yuan J, Sun Y, Zhang Q. Carbon Nanodots Memristor: An Emerging Candidate toward Artificial Biosynapse and Human Sensory Perception System. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2207229. [PMID: 37072642 PMCID: PMC10238223 DOI: 10.1002/advs.202207229] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 03/09/2023] [Indexed: 05/03/2023]
Abstract
In the era of big data and artificial intelligence (AI), advanced data storage and processing technologies are in urgent demand. The innovative neuromorphic algorithm and hardware based on memristor devices hold a promise to break the von Neumann bottleneck. In recent years, carbon nanodots (CDs) have emerged as a new class of nano-carbon materials, which have attracted widespread attention in the applications of chemical sensors, bioimaging, and memristors. The focus of this review is to summarize the main advances of CDs-based memristors, and their state-of-the-art applications in artificial synapses, neuromorphic computing, and human sensory perception systems. The first step is to systematically introduce the synthetic methods of CDs and their derivatives, providing instructive guidance to prepare high-quality CDs with desired properties. Then, the structure-property relationship and resistive switching mechanism of CDs-based memristors are discussed in depth. The current challenges and prospects of memristor-based artificial synapses and neuromorphic computing are also presented. Moreover, this review outlines some promising application scenarios of CDs-based memristors, including neuromorphic sensors and vision, low-energy quantum computation, and human-machine collaboration.
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Affiliation(s)
- Cheng Zhang
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy ApplicationSchool of Physical Science and TechnologySuzhou University of Science and TechnologySuzhouJiangsu215009China
| | - Mohan Chen
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy ApplicationSchool of Physical Science and TechnologySuzhou University of Science and TechnologySuzhouJiangsu215009China
| | - Yelong Pan
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy ApplicationSchool of Physical Science and TechnologySuzhou University of Science and TechnologySuzhouJiangsu215009China
| | - Yang Li
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy ApplicationSchool of Physical Science and TechnologySuzhou University of Science and TechnologySuzhouJiangsu215009China
| | - Kuaibing Wang
- Jiangsu Key Laboratory of Pesticide SciencesDepartment of ChemistryCollege of ScienceNanjing Agricultural UniversityNanjing210095China
| | - Junwei Yuan
- School of Chemistry and Life SciencesSuzhou University of Science and TechnologySuzhouJiangsu215009China
| | - Yanqiu Sun
- School of Chemistry and Life SciencesSuzhou University of Science and TechnologySuzhouJiangsu215009China
| | - Qichun Zhang
- Department of Materials Science and EngineeringDepartment of Chemistry and Center of Super‐Diamond and Advanced Films (COSDAF)City University of Hong Kong83 Tat Chee AvenueHong Kong999077China
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3
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Gulati S, Baul A, Amar A, Wadhwa R, Kumar S, Varma RS. Eco-Friendly and Sustainable Pathways to Photoluminescent Carbon Quantum Dots (CQDs). NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:554. [PMID: 36770515 PMCID: PMC9920802 DOI: 10.3390/nano13030554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 01/24/2023] [Accepted: 01/26/2023] [Indexed: 06/18/2023]
Abstract
Carbon quantum dots (CQDs), a new family of photoluminescent 0D NPs, have recently received a lot of attention. They have enormous future potential due to their unique properties, which include low toxicity, high conductivity, and biocompatibility and accordingly can be used as a feasible replacement for conventional materials deployed in various optoelectronic, biomedical, and energy applications. The most recent trends and advancements in the synthesizing and setup of photoluminescent CQDs using environmentally friendly methods are thoroughly discussed in this review. The eco-friendly synthetic processes are emphasized, with a focus on biomass-derived precursors. Modification possibilities for creating newer physicochemical properties among different CQDs are also presented, along with a brief conceptual overview. The extensive amount of writings on them found in the literature explains their exceptional competence in a variety of fields, making these nanomaterials promising alternatives for real-world applications. Furthermore, the benefits, drawbacks, and opportunities for CQDs are discussed, with an emphasis on their future prospects in this emerging research field.
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Affiliation(s)
- Shikha Gulati
- Department of Chemistry, Sri Venkateswara College, University of Delhi, Delhi 110021, India
| | - Arikta Baul
- Department of Chemistry, Sri Venkateswara College, University of Delhi, Delhi 110021, India
| | - Anoushka Amar
- Department of Chemistry, Sri Venkateswara College, University of Delhi, Delhi 110021, India
| | - Rachit Wadhwa
- Department of Chemistry, Sri Venkateswara College, University of Delhi, Delhi 110021, India
| | - Sanjay Kumar
- Department of Chemistry, Sri Venkateswara College, University of Delhi, Delhi 110021, India
| | - Rajender S. Varma
- Institute for Nanomaterials, Advanced Technologies, and Innovation (CxI), Technical University of Liberec (TUL), Studentská 1402/2, 461 17 Liberec, Czech Republic
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4
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Graphene quantum dots: synthesis, properties, and applications to the development of optical and electrochemical sensors for chemical sensing. Mikrochim Acta 2022; 189:258. [PMID: 35701638 DOI: 10.1007/s00604-022-05353-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/24/2022] [Indexed: 10/18/2022]
Abstract
GQDs exhibits exceptional electrochemical activity owing to their active edge sites that make them very attractive for biosensing applications. However, their use in the design of new biosensing devices for application to the detection and quantification of toxins, pathogens, and clinical biomarkers has so far not investigated in detail. In this regard, herein we provide a detailed review on various methodologies employed for the synthesis of GQDs, including bottom-up and top-down approaches, with a special focus on their applications in biosensing via fluorescence, photoluminescence, chemiluminescence, electrochemiluminescence, fluorescence resonance energy transfer, and electrochemical techniques. We believe that this review will shed light on the critical issues and widen the applications of GQDs for the design of biosensors with improved analytical response for future applications. HIGHLIGHTS: • Properties of GQDs play a critical role in biosensing applications. • Synthesis of GQDs using top-down and bottom-up approaches is discussed comprehensively. • Overview of advancements in GQD-based sensors over the last decade. • Methods for the design of selective and sensitive GQD-based sensors. • Challenges and opportunities for future GQD-based sensors.
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Kansara V, Tiwari S, Patel M. Graphene quantum dots: A review on the effect of synthesis parameters and theranostic applications. Colloids Surf B Biointerfaces 2022; 217:112605. [PMID: 35688109 DOI: 10.1016/j.colsurfb.2022.112605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/23/2022] [Accepted: 05/25/2022] [Indexed: 10/18/2022]
Abstract
The rising demand for early-stage diagnosis of diseases such as cancer, diabetes, neurodegenerative can be met with the development of materials offering high sensitivity and specificity. Graphene quantum dots (GQDs) have been investigated extensively for theranostic applications owing to their superior photostability and high aqueous dispersibility. These are attractive for a range of biomedical applications as their physicochemical and optoelectronic properties can be tuned precisely. However, many aspects of these properties remain to be explored. In the present review, we have discussed the effect of synthetic parameters upon their physicochemical characteristics relevant to bioimaging. We have highlighted the effect of particle properties upon sensing of biological molecules through 'turn-on' and 'turn-off' fluorescence and generation of electrochemical signals. After describing the effect of surface chemistry and solution pH on optical properties, an inclusive view on application of GQDs in drug delivery and radiation therapy has been given. Finally, a brief overview on their application in gene therapy has also been included.
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Affiliation(s)
- Vrushti Kansara
- Maliba Pharmacy College, Uka Tarsadia University, Gujarat, India
| | - Sanjay Tiwari
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research, Raebareli, Uttar Pradesh, India
| | - Mitali Patel
- Maliba Pharmacy College, Uka Tarsadia University, Gujarat, India.
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6
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Ke Y, Liu YC, Ren WW, Bai AM, Li XY, Hu YJ. Preparation of graphene quantum dots with glycine as nitrogen source and its interaction with human serum albumin. LUMINESCENCE 2021; 36:894-903. [PMID: 33440065 DOI: 10.1002/bio.4012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/24/2020] [Accepted: 01/07/2021] [Indexed: 12/26/2022]
Abstract
Graphene quantum dots (GQDs) could be regarded as graphene with a lateral dimension less than 100 nm. Compared with graphene, GQDs not only possess the excellent properties of graphene but also have been proven to have low toxicity, high fluorescence stability, strong water solubility, as well as better biocompatibility. In this work, an amide bond-based, N-doped graphene quantum dot was synthesized using a simple hydrothermal method. When the reaction time was 4 h and the temperature was 180°C, fluorescence excitation and emission peaks of the product were 340 nm and 450 nm, respectively. Its interaction with human serum albumin (HSA) was investigated using spectroscopy, gel electrophoresis, and molecular simulation. Gel electrophoresis showed that the product did not cause complete scission of the peptide chain in HSA, indicating good biocompatibility. The results of molecular docking showed that the product tended to bind to site III of HSA. This paper provides a meaningful reference for design and development in nanomedicine.
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Affiliation(s)
- Yi Ke
- Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi, China
| | - Yong-Chang Liu
- Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi, China
| | - Wen-Wen Ren
- Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi, China
| | - Ai-Min Bai
- Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi, China
| | - Xiao-Yun Li
- Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi, China
| | - Yan-Jun Hu
- Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi, China
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7
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Wang H, Lu W, Hou S, Yu B, Zhou Z, Xue Y, Guo R, Wang S, Zeng K, Yan X. A 2D-SnSe film with ferroelectricity and its bio-realistic synapse application. NANOSCALE 2020; 12:21913-21922. [PMID: 33112322 DOI: 10.1039/d0nr03724a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Catering to the general trend of artificial intelligence development, simulating humans' learning and thinking behavior has become the research focus. Second-order memristors, which are more analogous to biological synapses, are the most promising devices currently used in neuromorphic/brain-like computing. However, few second-order memristors based on two-dimensional (2D) materials have been reported, and the inherent bionic physics needs to be explored. In this work, a second-order memristor based on 2D SnSe films was fabricated by the pulsed laser deposition technique. The continuously adjustable conductance of Au/SnSe/NSTO structures was achieved by gradually switching the polarization of a ferroelectric SnSe layer. The experimental results show that the bio-synaptic functions, including spike-timing-dependent plasticity, short-term plasticity and long-term plasticity, can be simulated using this two-terminal devices. Moreover, stimulus pulses with nanosecond pulse duration were applied to the device to emulate rapid learning and long-term memory in the human brain. The observed memristive behavior is mainly attributed to the modulation of the width of the depletion layer and barrier height is affected, at the SnSe/NSTO interface, by the reversal of ferroelectric polarization of SnSe materials. The device energy consumption is as low as 66 fJ, being expected to be applied to miniaturized, high-density, low-power neuromorphic computing.
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Affiliation(s)
- Hong Wang
- Key Laboratory of Optoelectronic Information Materials of Hebei Province, Key Laboratory of Brain-Like Neuromorphic Devices and Systems of Hebei Province, Hebei University, Baoding 071002, China.
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8
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Lv Z, Wang Y, Chen J, Wang J, Zhou Y, Han ST. Semiconductor Quantum Dots for Memories and Neuromorphic Computing Systems. Chem Rev 2020; 120:3941-4006. [DOI: 10.1021/acs.chemrev.9b00730] [Citation(s) in RCA: 114] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Ziyu Lv
- Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, P. R. China
| | - Yan Wang
- Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, P. R. China
| | - Jingrui Chen
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, P. R. China
| | - Junjie Wang
- Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, P. R. China
| | - Ye Zhou
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, P. R. China
| | - Su-Ting Han
- Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, P. R. China
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9
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Guo B, Zuo Y, Shi Y, Han T, Lanza M. Transmission Electron Microscopy-Based Statistical Analysis of Commercially Available Graphene Oxide Quantum Dots. CRYSTAL RESEARCH AND TECHNOLOGY 2020. [DOI: 10.1002/crat.201900231] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Biyu Guo
- Institute of Functional Nano & Soft Materials; Collaborative Innovation Center of Suzhou Nano Science & Technology; Soochow University; 199 Ren-Ai Road Suzhou 215123 China
| | - Ying Zuo
- Institute of Functional Nano & Soft Materials; Collaborative Innovation Center of Suzhou Nano Science & Technology; Soochow University; 199 Ren-Ai Road Suzhou 215123 China
| | - Yuanyuan Shi
- Interuniversity Microelectronics Centre; Kapeldreef 75 Leuven B-3001 Belgium
| | - Tingting Han
- Institute of Functional Nano & Soft Materials; Collaborative Innovation Center of Suzhou Nano Science & Technology; Soochow University; 199 Ren-Ai Road Suzhou 215123 China
| | - Mario Lanza
- Institute of Functional Nano & Soft Materials; Collaborative Innovation Center of Suzhou Nano Science & Technology; Soochow University; 199 Ren-Ai Road Suzhou 215123 China
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Yan Y, Gong J, Chen J, Zeng Z, Huang W, Pu K, Liu J, Chen P. Recent Advances on Graphene Quantum Dots: From Chemistry and Physics to Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1808283. [PMID: 30828898 DOI: 10.1002/adma.201808283] [Citation(s) in RCA: 315] [Impact Index Per Article: 63.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 01/25/2019] [Indexed: 05/18/2023]
Abstract
Graphene quantum dots (GQDs) that are flat 0D nanomaterials have attracted increasing interest because of their exceptional chemicophysical properties and novel applications in energy conversion and storage, electro/photo/chemical catalysis, flexible devices, sensing, display, imaging, and theranostics. The significant advances in the recent years are summarized with comparative and balanced discussion. The differences between GQDs and other nanomaterials, including their nanocarbon cousins, are emphasized, and the unique advantages of GQDs for specific applications are highlighted. The current challenges and outlook of this growing field are also discussed.
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Affiliation(s)
- Yibo Yan
- Shaanxi Institute of Flexible Electronics, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, 710072, China
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457, Singapore
| | - Jun Gong
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457, Singapore
| | - Jie Chen
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457, Singapore
| | - Zhiping Zeng
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457, Singapore
| | - Wei Huang
- Shaanxi Institute of Flexible Electronics, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, 710072, China
| | - Kanyi Pu
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457, Singapore
| | - Jiyang Liu
- Department of Chemistry, School of Sciences, Zhejiang Sci-Tech University, 928 Second Avenue, Xiasha Higher Education Zone, Hangzhou, 310018, China
| | - Peng Chen
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457, Singapore
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11
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Gao S, Yi X, Shang J, Liu G, Li RW. Organic and hybrid resistive switching materials and devices. Chem Soc Rev 2019; 48:1531-1565. [DOI: 10.1039/c8cs00614h] [Citation(s) in RCA: 211] [Impact Index Per Article: 42.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This review presents a timely and comprehensive summary of organic and hybrid materials for nonvolatile resistive switching memory applications in the “More than Moore” era, with particular attention on their designing principles for electronic property tuning and flexible memory performance.
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Affiliation(s)
- Shuang Gao
- CAS Key Laboratory of Magnetic Materials and Devices
- Ningbo Institute of Materials Technology and Engineering
- Chinese Academy of Sciences
- Ningbo
- China
| | - Xiaohui Yi
- CAS Key Laboratory of Magnetic Materials and Devices
- Ningbo Institute of Materials Technology and Engineering
- Chinese Academy of Sciences
- Ningbo
- China
| | - Jie Shang
- CAS Key Laboratory of Magnetic Materials and Devices
- Ningbo Institute of Materials Technology and Engineering
- Chinese Academy of Sciences
- Ningbo
- China
| | - Gang Liu
- CAS Key Laboratory of Magnetic Materials and Devices
- Ningbo Institute of Materials Technology and Engineering
- Chinese Academy of Sciences
- Ningbo
- China
| | - Run-Wei Li
- CAS Key Laboratory of Magnetic Materials and Devices
- Ningbo Institute of Materials Technology and Engineering
- Chinese Academy of Sciences
- Ningbo
- China
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12
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Komrapit N, Punyodom W, Worajittiphon P. Compatibilizing and reinforcing an immiscible blend based on poly(lactic acid) with delaminated graphite: From raw graphite to enhanced polymer mechanical properties. J Appl Polym Sci 2018. [DOI: 10.1002/app.46821] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Nopparat Komrapit
- Department of Chemistry, Faculty of Science; Chiang Mai University; Chiang Mai 50200 Thailand
- Graduate School; Chiang Mai University; Chiang Mai 50200 Thailand
| | - Winita Punyodom
- Department of Chemistry, Faculty of Science; Chiang Mai University; Chiang Mai 50200 Thailand
- Center of Excellence in Materials Science and Technology; Chiang Mai University; Chiang Mai 50200 Thailand
| | - Patnarin Worajittiphon
- Department of Chemistry, Faculty of Science; Chiang Mai University; Chiang Mai 50200 Thailand
- Center of Excellence in Materials Science and Technology; Chiang Mai University; Chiang Mai 50200 Thailand
- Center of Excellence for Innovation in Chemistry, Faculty of Science; Chiang Mai University; Chiang Mai 50200 Thailand
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13
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Enhancement of graphene quantum dots based applications via optimum physical chemistry: A review. Biocybern Biomed Eng 2018. [DOI: 10.1016/j.bbe.2018.03.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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14
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Lin Z, Karthik PS, Hada M, Nishikawa T, Hayashi Y. Simple Technique of Exfoliation and Dispersion of Multilayer Graphene from Natural Graphite by Ozone-Assisted Sonication. NANOMATERIALS 2017; 7:nano7060125. [PMID: 28555015 PMCID: PMC5485772 DOI: 10.3390/nano7060125] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 05/18/2017] [Accepted: 05/24/2017] [Indexed: 02/03/2023]
Abstract
Owing to its unique properties, graphene has attracted tremendous attention in many research fields. There is a great space to develop graphene synthesis techniques by an efficient and environmentally friendly approach. In this paper, we report a facile method to synthesize well-dispersed multilayer graphene (MLG) without using any chemical reagents or organic solvents. This was achieved by the ozone-assisted sonication of the natural graphite in a water medium. The frequency or number of ozone treatments plays an important role for the dispersion in the process. The possible mechanism of graphene exfoliation and the introduction of functional groups have been postulated. The experimental setup is unique for ozone treatment and enables the elimination of ozone off-gas. The heat generated by the dissipation of ultrasonic waves was used as it is, and no additional heat was supplied. The graphene dispersion was stable, and no evidence of aggregation was observed---even after several months. The characterization results show that well-dispersed MLG was successfully synthesized without any significant damage to the overall structure. The graphene obtained by this method has potential applications in composite materials, conductive coatings, energy storage, and electronic devices.
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Affiliation(s)
- Zaw Lin
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.
| | - Paneer Selvam Karthik
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.
| | - Masaki Hada
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.
| | - Takeshi Nishikawa
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.
| | - Yasuhiko Hayashi
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.
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15
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Wang C, He W, Tong Y, Zhang Y, Huang K, Song L, Zhong S, Ganeshkumar R, Zhao R. Memristive Devices with Highly Repeatable Analog States Boosted by Graphene Quantum Dots. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1603435. [PMID: 28296020 DOI: 10.1002/smll.201603435] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 01/30/2017] [Indexed: 06/06/2023]
Abstract
Memristive devices, having a huge potential as artificial synapses for low-power neural networks, have received tremendous attention recently. Despite great achievements in demonstration of plasticity and learning functions, little progress has been made in the repeatable analog resistance states of memristive devices, which is, however, crucial for achieving controllable synaptic behavior. The controllable behavior of synapse is highly desired in building neural networks as it helps reduce training epochs and diminish error probability. Fundamentally, the poor repeatability of analog resistance states is closely associated with the random formation of conductive filaments, which consists of oxygen vacancies. In this work, graphene quantum dots (GQDs) are introduced into memristive devices. By virtue of the abundant oxygen anions released from GQDs, the GQDs can serve as nano oxygen-reservoirs and enhance the localization of filament formation. As a result, analog resistance states with highly tight distribution are achieved with nearly 85% reduction in variations. In addition the insertion of GQDs can alter the energy band alignment and boost the tunneling current, which leads to significant reduction in both switching voltages and their distribution variations. This work may pave the way for achieving artificial neural networks with accurate and efficient learning capability.
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Affiliation(s)
- Changhong Wang
- Engineering Product Development, Singapore University of Technology and Design (SUTD), 8 Somapah Road, 487372, Singapore
| | - Wei He
- Engineering Product Development, Singapore University of Technology and Design (SUTD), 8 Somapah Road, 487372, Singapore
| | - Yi Tong
- Engineering Product Development, Singapore University of Technology and Design (SUTD), 8 Somapah Road, 487372, Singapore
| | - Yishu Zhang
- Engineering Product Development, Singapore University of Technology and Design (SUTD), 8 Somapah Road, 487372, Singapore
| | - Kejie Huang
- Engineering Product Development, Singapore University of Technology and Design (SUTD), 8 Somapah Road, 487372, Singapore
| | - Li Song
- Engineering Product Development, Singapore University of Technology and Design (SUTD), 8 Somapah Road, 487372, Singapore
| | - Shuai Zhong
- Engineering Product Development, Singapore University of Technology and Design (SUTD), 8 Somapah Road, 487372, Singapore
| | - Rajasekaran Ganeshkumar
- Engineering Product Development, Singapore University of Technology and Design (SUTD), 8 Somapah Road, 487372, Singapore
| | - Rong Zhao
- Engineering Product Development, Singapore University of Technology and Design (SUTD), 8 Somapah Road, 487372, Singapore
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16
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Zhou S, Xu H, Gan W, Yuan Q. Graphene quantum dots: recent progress in preparation and fluorescence sensing applications. RSC Adv 2016. [DOI: 10.1039/c6ra24349e] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
This paper reviews recent activities in the preparation and fluorescence sensing applications of graphene quantum dots.
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Affiliation(s)
- Shenghai Zhou
- College of Chemistry and Chemical Engineering
- Hebei Normal University for Nationalities
- Chengde 067000
- China
- Laboratory of Environmental Science and Technology
| | - Hongbo Xu
- College of Chemistry and Chemical Engineering
- Hebei Normal University for Nationalities
- Chengde 067000
- China
- Laboratory of Environmental Science and Technology
| | - Wei Gan
- School of Natural Sciences and Humanities
- Harbin Institute of Technology
- Shenzhen 518055
- China
- Laboratory of Environmental Science and Technology
| | - Qunhui Yuan
- School of Materials Science and Engineering
- Harbin Institute of Technology
- Shenzhen 518055
- China
- Laboratory of Environmental Science and Technology
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17
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Sarkar S, Gandla D, Venkatesh Y, Bangal PR, Ghosh S, Yang Y, Misra S. Graphene quantum dots from graphite by liquid exfoliation showing excitation-independent emission, fluorescence upconversion and delayed fluorescence. Phys Chem Chem Phys 2016; 18:21278-87. [DOI: 10.1039/c6cp01528j] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Schematic representation of GQD formation from graphite.
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Affiliation(s)
- Suprabhat Sarkar
- Nanomaterials Laboratory
- Inorganic and Physical Chemistry Division
- CSIR-IICT
- Hyderabad-500007
- India
| | - Dayakar Gandla
- Nanomaterials Laboratory
- Inorganic and Physical Chemistry Division
- CSIR-IICT
- Hyderabad-500007
- India
| | - Yeduru Venkatesh
- Academy of Scientific and Innovative Research (AcSIR)
- Anusandhan Bhawan
- New Delhi-110001
- India
- Inorganic and Physical Chemistry Division
| | - Prakriti Ranjan Bangal
- Academy of Scientific and Innovative Research (AcSIR)
- Anusandhan Bhawan
- New Delhi-110001
- India
- Inorganic and Physical Chemistry Division
| | - Sutapa Ghosh
- Nanomaterials Laboratory
- Inorganic and Physical Chemistry Division
- CSIR-IICT
- Hyderabad-500007
- India
| | - Yang Yang
- Chemistry and Biochemistry Division
- Rowan University
- Glassboro
- USA
| | - Sunil Misra
- Biology Division
- CSIR-IICT
- Hyderabad-500007
- India
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