Graphene quantum dot

Last updated

Graphene quantum dots (GQDs) are graphene nanoparticles with a size less than 100 nm. [1] Due to their exceptional properties such as low toxicity, stable photoluminescence, chemical stability and pronounced quantum confinement effect, GQDs are considered as a novel material for biological, opto-electronics, energy and environmental applications. [2]

Contents

Properties

Graphene quantum dots (GQDs) consist of one or a few layers of graphene and are smaller than 100 nm in size. [3] [1] They are chemically and physically stable, have a large surface to mass ratio and can be dispersed in water easily due to functional groups at the edges. [4] [5] The fluorescence emission of GQDs can extend across a broad spectral range, including the UV, visible, and IR. The origin of GQD fluorescence emission is a subject of debate, as it has been related to quantum confinement effects, defect states and functional groups [6] [7] that might depend on the pH, when GQDs are dispersed in water. [8] Their electronic structure depends sensitively on the crystallographic orientation of their edges, for example zigzag-edge GQDs with 7-8 nm diameter show a metallic behavior. [9] In general, their energy gap decreases, when the number of graphene layers or the number of carbon atoms per graphene layer is increased. [10]

Health and safety

The toxicity of graphene-family nanoparticles is a matter of ongoing research. [2] [11] The toxicity (both in vivo and cytotoxicity) of GQDs are related to a variety of factors including particle size, methods of synthesis, chemical doping and so on. [12] Many authors claim, that GQDs are biocompatible and cause only low toxicity [4] [13] as they are just composed of organic materials, which should lead to an advantage over semiconductor quantum dots. [5] Several in vitro studies, based on cell cultures, show only marginal effects of GQDs on the viability of human cells. [1] [14] [15] [16] An in-depth look at the gene expression changes caused by GQDs with a size of 3 nm revealed that only one, namely the selenoprotein W, 1 out of 20 800 gene expressions was affected significantly in primary human hematopoietic stem cells. [17] On the contrary, other in vitro studies observe a distinct decrease of cell viability and the induction of autophagy after exposure of the cells to GQDs [18] and one in vivo study in zebrafish larvae observed the alteration of 2116 gene expressions. [19] These inconsistent findings may be attributed to the diversity of the used GQDs, as the related toxicity is dependent on particle size, surface functional groups, oxygen content, surface charges and impurities. [20] Currently, the literature is insufficient to draw conclusions about the potential hazards of GQDs. [11]

Preparation

Presently, a range of techniques have been developed to prepare GQDs. These methods are normally classified into two groups top down and bottom up. Top down approaches applied different techniques to cut bulk graphitic materials into GQDs including graphite, graphene, carbon nanotubes, coal, carbon black and carbon fibres. These techniques mainly include electron beam lithography, chemical synthesis, electrochemical preparation, graphene oxide (GO) reduction, C60 catalytic transformation, the microwave assisted hydrothermal method (MAH), [21] [22] the Soft-Template method, [23] the hydrothermal method, [24] [25] [26] and the ultrasonic exfoliation method. [27] Top down methods usually need intense purification as strong mixed acids are used in these methods. On the other hand, bottom up methods assemble GQDs from small organic molecules such as citric acid [28] and glucose. These GQDs have better biocompatibility. [12]

Application

Graphene quantum dots are studied as an advanced multifunctional material due to their unique optical, electronic, [9] spin, [29] and photoelectric properties induced by the quantum confinement effect and edge effect. They have possible applications in treatment of Alzheimer's disease, [1] bioimaging, [30] photothermal therapy, [3] [31] temperature sensing, [32] drug delivery, [33] [34] LEDs lighter converters, photodetectors, OPV solar cells, and photoluminescent material, biosensors fabrication. [35]

See also

Related Research Articles

Nanomedicine is the medical application of nanotechnology. Nanomedicine ranges from the medical applications of nanomaterials and biological devices, to nanoelectronic biosensors, and even possible future applications of molecular nanotechnology such as biological machines. Current problems for nanomedicine involve understanding the issues related to toxicity and environmental impact of nanoscale materials.

<span class="mw-page-title-main">Thermoelectric materials</span> Materials whose temperature variance leads to voltage change

Thermoelectric materials show the thermoelectric effect in a strong or convenient form.

<span class="mw-page-title-main">Quantum dot</span> Zero-dimensional, nano-scale semiconductor particles with novel optical and electronic properties

Quantum dots (QDs) or semiconductor nanocrystals are semiconductor particles a few nanometres in size with optical and electronic properties that differ from those of larger particles via quantum mechanical effects. They are a central topic in nanotechnology and materials science. When a quantum dot is illuminated by UV light, an electron in the quantum dot can be excited to a state of higher energy. In the case of a semiconducting quantum dot, this process corresponds to the transition of an electron from the valence band to the conductance band. The excited electron can drop back into the valence band releasing its energy as light. This light emission (photoluminescence) is illustrated in the figure on the right. The color of that light depends on the energy difference between the conductance band and the valence band, or the transition between discrete energy states when the band structure is no longer well-defined in QDs.

<span class="mw-page-title-main">Graphene</span> Hexagonal lattice made of carbon atoms

Graphene is an allotrope of carbon consisting of a single layer of atoms arranged in a hexagonal lattice nanostructure. The name is derived from "graphite" and the suffix -ene, reflecting the fact that the graphite allotrope of carbon contains numerous double bonds.

<span class="mw-page-title-main">Nanoparticle</span> Particle with size less than 100 nm

A nanoparticle or ultrafine particle is a particle of matter 1 to 100 nanometres (nm) in diameter. The term is sometimes used for larger particles, up to 500 nm, or fibers and tubes that are less than 100 nm in only two directions. At the lowest range, metal particles smaller than 1 nm are usually called atom clusters instead.

<span class="mw-page-title-main">Erbium(III) oxide</span> Chemical compound

Erbium(III) oxide is the inorganic compound with the formula Er2O3. It is a pink paramagnetic solid. It finds uses in various optical materials.

<span class="mw-page-title-main">Nanobatteries</span> Type of battery

Nanobatteries are fabricated batteries employing technology at the nanoscale, particles that measure less than 100 nanometers or 10−7 meters. These batteries may be nano in size or may use nanotechnology in a macro scale battery. Nanoscale batteries can be combined to function as a macrobattery such as within a nanopore battery.

As the world's energy demand continues to grow, the development of more efficient and sustainable technologies for generating and storing energy is becoming increasingly important. According to Dr. Wade Adams from Rice University, energy will be the most pressing problem facing humanity in the next 50 years and nanotechnology has potential to solve this issue. Nanotechnology, a relatively new field of science and engineering, has shown promise to have a significant impact on the energy industry. Nanotechnology is defined as any technology that contains particles with one dimension under 100 nanometers in length. For scale, a single virus particle is about 100 nanometers wide.

<span class="mw-page-title-main">Graphene nanoribbon</span> Carbon allotrope

Graphene nanoribbons are strips of graphene with width less than 100 nm. Graphene ribbons were introduced as a theoretical model by Mitsutaka Fujita and coauthors to examine the edge and nanoscale size effect in graphene.

<span class="mw-page-title-main">Photon upconversion</span> Optical process

Photon upconversion (UC) is a process in which the sequential absorption of two or more photons leads to the emission of light at shorter wavelength than the excitation wavelength. It is an anti-Stokes type emission. An example is the conversion of infrared light to visible light. Upconversion can take place in both organic and inorganic materials, through a number of different mechanisms. Organic molecules that can achieve photon upconversion through triplet-triplet annihilation are typically polycyclic aromatic hydrocarbons (PAHs). Inorganic materials capable of photon upconversion often contain ions of d-block or f-block elements. Examples of these ions are Ln3+, Ti2+, Ni2+, Mo3+, Re4+, Os4+, and so on.

<span class="mw-page-title-main">Core–shell semiconductor nanocrystal</span>

Core–shell semiconducting nanocrystals (CSSNCs) are a class of materials which have properties intermediate between those of small, individual molecules and those of bulk, crystalline semiconductors. They are unique because of their easily modular properties, which are a result of their size. These nanocrystals are composed of a quantum dot semiconducting core material and a shell of a distinct semiconducting material. The core and the shell are typically composed of type II–VI, IV–VI, and III–V semiconductors, with configurations such as CdS/ZnS, CdSe/ZnS, CdSe/CdS, and InAs/CdSe Organically passivated quantum dots have low fluorescence quantum yield due to surface related trap states. CSSNCs address this problem because the shell increases quantum yield by passivating the surface trap states. In addition, the shell provides protection against environmental changes, photo-oxidative degradation, and provides another route for modularity. Precise control of the size, shape, and composition of both the core and the shell enable the emission wavelength to be tuned over a wider range of wavelengths than with either individual semiconductor. These materials have found applications in biological systems and optics.

CytoViva, Inc. is a scientific imaging and instrumentation company that develops and markets optical microscopy and hyperspectral imaging technology for nanomaterials, pathogen and general biology applications.

Potential graphene applications include lightweight, thin, and flexible electric/photonics circuits, solar cells, and various medical, chemical and industrial processes enhanced or enabled by the use of new graphene materials.

<span class="mw-page-title-main">Chemiresistor</span>

A chemiresistor is a material that changes its electrical resistance in response to changes in the nearby chemical environment. Chemiresistors are a class of chemical sensors that rely on the direct chemical interaction between the sensing material and the analyte. The sensing material and the analyte can interact by covalent bonding, hydrogen bonding, or molecular recognition. Several different materials have chemiresistor properties: semiconducting metal oxides, some conductive polymers, and nanomaterials like graphene, carbon nanotubes and nanoparticles. Typically these materials are used as partially selective sensors in devices like electronic tongues or electronic noses.

<span class="mw-page-title-main">Carbon quantum dot</span> Type of carbon nanoparticle

Carbon quantum dots also commonly called carbon nano dots are carbon nanoparticles which are less than 10 nm in size and have some form of surface passivation.

Niveen M. Khashab is a Lebanese chemist and an associate Professor of chemical Sciences and engineering at King Abdullah University of Science and Technology in Saudi Arabia since 2009. She is a laureate of the 2017 L'Oréal-UNESCO Awards for Women in Science "for her contributions to innovative smart hybrid materials aimed at drug delivery and for developing new techniques to monitor intracellular antioxidant activity." She is also a fellow of the Royal Chemical Society, and a member of the American Chemical Society.

Quantum dots (QDs) are semiconductor nanoparticles with a size less than 10 nm. They exhibited size-dependent properties especially in the optical absorption and the photoluminescence (PL). Typically, the fluorescence emission peak of the QDs can be tuned by changing their diameters. So far, QDs were consisted of different group elements such as CdTe, CdSe, CdS in the II-VI category, InP or InAs in the III-V category, CuInS2 or AgInS2 in the I–III–VI2 category, and PbSe/PbS in the IV-VI category. These QDs are promising candidates as fluorescent labels in various biological applications such as bioimaging, biosensing and drug delivery.

<span class="mw-page-title-main">Boron nitride nanosheet</span>

Boron nitride nanosheet is a crystalline form of the hexagonal boron nitride (h-BN), which has a thickness of one atom. Similar in geometry as well as physical and thermal properties to its carbon analog graphene, but has very different chemical and electronic properties – contrary to the black and highly conducting graphene, BN nanosheets are electrical insulators with a band gap of ~5.9 eV, and therefore appear white in color.

<span class="mw-page-title-main">Electronic properties of graphene</span>

Graphene is a semimetal whose conduction and valence bands meet at the Dirac points, which are six locations in momentum space, the vertices of its hexagonal Brillouin zone, divided into two non-equivalent sets of three points. The two sets are labeled K and K'. The sets give graphene a valley degeneracy of gv = 2. By contrast, for traditional semiconductors the primary point of interest is generally Γ, where momentum is zero. Four electronic properties separate it from other condensed matter systems.

Silicon quantum dots are metal-free biologically compatible quantum dots with photoluminescence emission maxima that are tunable through the visible to near-infrared spectral regions. These quantum dots have unique properties arising from their indirect band gap, including long-lived luminescent excited-states and large Stokes shifts. A variety of disproportionation, pyrolysis, and solution protocols have been used to prepare silicon quantum dots, however it is important to note that some solution-based protocols for preparing luminescent silicon quantum dots actually yield carbon quantum dots instead of the reported silicon. The unique properties of silicon quantum dots lend themselves to an array of potential applications: biological imaging, luminescent solar concentrators, light emitting diodes, sensors, and lithium-ion battery anodes.

References

  1. 1 2 3 4 Ghosh, Shampa; Sachdeva, Bhuvi; Sachdeva, Punya; Chaudhary, Vishal; Rani, Gokana Mohana; Sinha, Jitendra Kumar (2022-10-01). "Graphene quantum dots as a potential diagnostic and therapeutic tool for the management of Alzheimer's disease". Carbon Letters. 32 (6): 1381–1394. doi:10.1007/s42823-022-00397-9. ISSN   2233-4998. S2CID   252188554.
  2. 1 2 Henna, T. K.; Pramod, K. (May 2020). "Graphene quantum dots redefine nanobiomedicine". Materials Science & Engineering. C, Materials for Biological Applications. 110: 110651. doi:10.1016/j.msec.2020.110651. ISSN   1873-0191. PMID   32204078. S2CID   213861659.
  3. 1 2 Campbell, Elizabeth; Hasan, Md Tanvir; Gonzalez-Rodriguez, Roberto; Truly, Tate; Lee, Bong Han; Green, Kayla N.; Akkaraju, Giridhar; Naumov, Anton V. (October 2021). "Graphene quantum dot formulation for cancer imaging and redox-based drug delivery". Nanomedicine: Nanotechnology, Biology and Medicine. 37: 102408. doi:10.1016/j.nano.2021.102408. ISSN   1549-9642. PMID   34015513. S2CID   235075216.
  4. 1 2 Tian, P.; Tang, L.; Teng, K.S.; Lau, S.P. (2018). "Graphene quantum dots from chemistry to applications". Materials Today Chemistry. 10: 221–258. doi: 10.1016/j.mtchem.2018.09.007 . hdl: 10397/80356 .
  5. 1 2 Wang, Dan; Chen, Jiang-Fen; Dai, Liming (2014). "Recent Advances in Graphene Quantum Dots for Fluorescence Bioimaging from Cells through Tissues to Animals". Particle & Particle Systems Characterization. 32 (5): 515–523. doi:10.1002/ppsc.201400219. S2CID   53120598.
  6. ↑ Pan, Dengyu; Zhang, Jingchun; Li, Zhen; Wu, Minghong (2010). "Hydrothermal Route for Cutting Graphene Sheets into Blue‐Luminescent Graphene Quantum Dots". Advanced Materials. 22 (6): 734–738. Bibcode:2010AdM....22..734P. doi:10.1002/adma.200902825. PMID   20217780. S2CID   39981399.
  7. ↑ Wang, Shujun; Cole, Ivan S.; Zhao, Dongyuan; Li, Qin (2016). "The dual roles of functional groups in the photoluminescence of graphene quantum dots". Nanoscale. 8 (14): 7449–7458. Bibcode:2016Nanos...8.7449W. doi:10.1039/C5NR07042B. hdl: 10072/142465 . PMID   26731007.
  8. ↑ Wu, Zhu Lian; Gao, Ming Xuan; Wang, Ting Ting; Wan, Xiao Yan; Zheng, Lin Ling; Huang, Cheng Zhi (2014). "A general quantitative pH sensor developed with dicyandiamide N-doped high quantum yield graphene quantum dots". Nanoscale. 6 (7): 3868–3874. Bibcode:2014Nanos...6.3868W. doi:10.1039/C3NR06353D. PMID   24589665.
  9. 1 2 Ritter, Kyle A; Lyding, Joseph W (2009). "The influence of edge structure on the electronic properties of graphene quantum dots and nanoribbons". Nature Materials. 8 (3): 235–42. Bibcode:2009NatMa...8..235R. doi:10.1038/nmat2378. PMID   19219032.
  10. ↑ Wimmenauer, Christian; Scheller, Julienne; Fasbender, Stefan; Heinzel, Thomas (2019). "Single-particle energy – and optical absorption – spectra of multilayer graphene quantum dots". Superlattices and Microstructures. 132: 106171. doi:10.1016/j.spmi.2019.106171. S2CID   198435346.
  11. 1 2 Ou, Lingling; Song, Bin; Liang, Huimin; Liu, Jia; Feng, Xiaoli; Deng, Bin; Sun, Ting; Shao, Longquan (31 October 2016). "Toxicity of graphene-family nanoparticles: a general review of the origins and mechanisms". Particle and Fibre Toxicology. 13 (1): 57. doi: 10.1186/s12989-016-0168-y . PMC   5088662 . PMID   27799056.
  12. 1 2 Wang, Shujun; Cole, Ivan S.; Li, Qin (2016). "The toxicity of graphene quantum dots". RSC Advances. 6 (92): 89867–89878. Bibcode:2016RSCAd...689867W. doi:10.1039/C6RA16516H.
  13. ↑ Shen, Jianhua; Zhu, Yihua; Yang, Xiaoling; Li, Chunzhong (2012). "Graphene quantum dots: emergent nanolights for bioimaging, sensors, catalysis and photovoltaic devices". Chemical Communications. 48 (31): 3686–3699. doi:10.1039/C2CC00110A. PMID   22410424.
  14. ↑ Shang, Weihu; Zhang, Xiaoyan; Zhang, Mo; Fan, Zetan; Sun, Ying; Han, Mei; Fan, Louzhen (2014). "The uptake mechanism and biocompatibility of graphene quantum dots with human neural stem cells". Nanoscale. 6 (11): 5799–5806. Bibcode:2014Nanos...6.5799S. doi:10.1039/c3nr06433f. PMID   24740121.
  15. ↑ Fasbender, Stefan; Allani, Sonja; Wimmenauer, Christian; Cadeddu, Ron-Patrick; Raba, Katharina; Fischer, Johannes C.; Bulat, Bekir; Luysberg, Martina; Seidel, Claus A. M.; Heinzel, Thomas; Haas, Rainer (2017). "Uptake dynamics of graphene quantum dots into primary human blood cells following in vitro exposure". RSC Advances. 7 (20): 12208–12216. Bibcode:2017RSCAd...712208F. doi: 10.1039/C6RA27829A .
  16. ↑ Zhu, Shoujun; Zhang, Junhu; Qiao, Chunyan; Tang, Shijia; Li, Yunfeng; Yuan, Wenjing; Li, Bo; Tian, Lu; Liu, Fang; Hu, Rui; Gao, Hainan; Wei, Haotong; Zhang, Hao; Sun, Hongchen; Yang, Bai (2011). "Strongly green-photoluminescent graphene quantum dots for bioimaging applications". Chemical Communications. 47 (24): 6858–60. doi:10.1039/c1cc11122a. PMID   21584323.
  17. ↑ Fasbender, Stefan; Zimmermann, Lisa; Cadeddu, Ron-Patrick; Luysberg, Martina; Moll, Bastian; Janiak, Christoph; Heinzel, Thomas; Haas, Rainer (19 August 2019). "The Low Toxicity of Graphene Quantum Dots is Reflected by Marginal Gene Expression Changes of Primary Human Hematopoietic Stem Cells". Scientific Reports. 9 (1): 12028. Bibcode:2019NatSR...912028F. doi:10.1038/s41598-019-48567-6. PMC   6700176 . PMID   31427693.
  18. ↑ Xie, Yichun; Wan, Bin; Yang, Yu; Cui, Xuejing; Xin, Yan; Guo, Liang-Hong (March 2019). "Cytotoxicity and autophagy induction by graphene quantum dots with different functional groups". Journal of Environmental Sciences. 77: 198–209. doi:10.1016/j.jes.2018.07.014. PMID   30573083. S2CID   58555272.
  19. ↑ Deng, Shun; Jia, Pan-Pan; Zhang, Jing-Hui; Junaid, Muhammad; Niu, Aping; Ma, Yan-Bo; Fu, Ailing; Pei, De-Sheng (September 2018). "Transcriptomic response and perturbation of toxicity pathways in zebrafish larvae after exposure to graphene quantum dots (GQDs)". Journal of Hazardous Materials. 357: 146–158. doi:10.1016/j.jhazmat.2018.05.063. PMID   29883909. S2CID   47013910.
  20. ↑ Guo, Xiaoqing; Mei, Nan (March 2014). "Assessment of the toxic potential of graphene family nanomaterials". Journal of Food and Drug Analysis. 22 (1): 105–115. doi:10.1016/j.jfda.2014.01.009. PMC   6350507 . PMID   24673908.
  21. ↑ Tang, Libin; Ji, Rongbin; Cao, Xiangke; Lin, Jingyu; Jiang, Hongxing; Li, Xueming; Teng, Kar Seng; Luk, Chi Man; Zeng, Songjun; Hao, Jianhua; Lau, Shu Ping (2012). "Deep Ultraviolet Photoluminescence of Water-Soluble Self-Passivated Graphene Quantum Dots". ACS Nano. 6 (6): 5102–10. doi:10.1021/nn300760g. hdl: 10397/28413 . PMID   22559247.
  22. ↑ Tang, Libin; Ji, Rongbin; Li, Xueming; Bai, Gongxun; Liu, Chao Ping; Hao, Jianhua; Lin, Jingyu; Jiang, Hongxing; Teng, Kar Seng; Yang, Zhibin; Lau, Shu Ping (2014). "Deep Ultraviolet to Near-Infrared Emission and Photoresponse in Layered N-Doped Graphene Quantum Dots". ACS Nano. 8 (6): 6312–20. doi:10.1021/nn501796r. PMID   24848545.
  23. ↑ Tang, Libin; Ji, Rongbin; Li, Xueming; Teng, Kar Seng; Lau, Shu Ping (2013). "Size-Dependent Structural and Optical Characteristics of Glucose-Derived Graphene Quantum Dots". Particle & Particle Systems Characterization. 30 (6): 523–31. doi:10.1002/ppsc.201200131. hdl: 10397/32222 . S2CID   96410135.
  24. ↑ Li, Xueming; Lau, Shu Ping; Tang, Libin; Ji, Rongbin; Yang, Peizhi (2013). "Multicolour light emission from chlorine-doped graphene quantum dots". Journal of Materials Chemistry C. 1 (44): 7308–13. doi:10.1039/C3TC31473A. hdl: 10397/34810 .
  25. ↑ Li, Lingling; Wu, Gehui; Yang, Guohai; Peng, Juan; Zhao, Jianwei; Zhu, Jun-Jie (2013). "Focusing on luminescent graphene quantum dots: Current status and future perspectives". Nanoscale. 5 (10): 4015–39. Bibcode:2013Nanos...5.4015L. doi:10.1039/C3NR33849E. PMID   23579482.
  26. ↑ Li, Xueming; Lau, Shu Ping; Tang, Libin; Ji, Rongbin; Yang, Peizhi (2014). "Sulphur doping: A facile approach to tune the electronic structure and optical properties of graphene quantum dots". Nanoscale. 6 (10): 5323–8. Bibcode:2014Nanos...6.5323L. doi:10.1039/C4NR00693C. hdl: 10397/34914 . PMID   24699893.
  27. ↑ Zhao, Jianhong; Tang, Libin; Xiang, Jinzhong; Ji, Rongbin; Yuan, Jun; Zhao, Jun; Yu, Ruiyun; Tai, Yunjian; Song, Liyuan (2014). "Chlorine doped graphene quantum dots: Preparation, properties, and photovoltaic detectors". Applied Physics Letters. 105 (11): 111116. Bibcode:2014ApPhL.105k1116Z. doi:10.1063/1.4896278.
  28. ↑ Wang, Shujun; Chen, Zhi-Gang; Cole, Ivan; Li, Qin (February 2015). "Structural evolution of graphene quantum dots during thermal decomposition of citric acid and the corresponding photoluminescence". Carbon. 82: 304–313. doi:10.1016/j.carbon.2014.10.075. hdl: 10072/69171 .
  29. ↑ Güçlü, A. D; Potasz, P; Hawrylak, P (2011). "Electric-field controlled spin in bilayer triangular graphene quantum dots". Physical Review B. 84 (3): 035425. arXiv: 1104.3108 . Bibcode:2011PhRvB..84c5425G. doi:10.1103/PhysRevB.84.035425. S2CID   119211816.
  30. ↑ Lu, Huiting; Li, Wenjun; Dong, Haifeng; Wei, Menglian (September 2019). "Graphene Quantum Dots for Optical Bioimaging". Small. 15 (36): e1902136. doi:10.1002/smll.201902136. ISSN   1613-6829. PMID   31304647. S2CID   196617689.
  31. ↑ Thakur, Mukeshchand; Kumawat, Mukesh Kumar; Srivastava, Rohit (2017). "Multifunctional graphene quantum dots for combined photothermal and photodynamic therapy coupled with cancer cell tracking applications". RSC Advances. 7 (9): 5251–61. Bibcode:2017RSCAd...7.5251T. doi: 10.1039/C6RA25976F .
  32. ↑ Kumawat, Mukesh Kumar; Thakur, Mukeshchand; Gurung, Raju B; Srivastava, Rohit (2017). "Graphene Quantum Dots from Mangifera indica: Application in Near-Infrared Bioimaging and Intracellular Nanothermometry". ACS Sustainable Chemistry & Engineering. 5 (2): 1382–91. doi:10.1021/acssuschemeng.6b01893.
  33. ↑ Kersting, David; Fasbender, Stefan; Pilch, Rabea; Kurth, Jennifer; Franken, André; Ludescher, Marina; Naskou, Johanna; Hallenberger, Angelika; Gall, Charlotte von; Mohr, Corinna J; Lukowski, Robert; Raba, Katharina; Jaschinski, Sandra; Esposito, Irene; Fischer, Johannes C; Fehm, Tanja; Niederacher, Dieter; Neubauer, Hans; Heinzel, Thomas (27 September 2019). "From in vitro to ex vivo: subcellular localization and uptake of graphene quantum dots into solid tumors". Nanotechnology. 30 (39): 395101. Bibcode:2019Nanot..30M5101K. doi: 10.1088/1361-6528/ab2cb4 . PMID   31239418.
  34. ↑ Thakur, Mukeshchand; Mewada, Ashmi; Pandey, Sunil; Bhori, Mustansir; Singh, Kanchanlata; Sharon, Maheshwar; Sharon, Madhuri (2016). "Milk-derived multi-fluorescent graphene quantum dot-based cancer theranostic system". Materials Science and Engineering: C. 67: 468–477. doi:10.1016/j.msec.2016.05.007. PMID   27287144.
  35. ↑ Bogireddy, Naveen Kumar Reddy; Barba, Victor; Agarwal, Vivechana (2019). "Nitrogen-Doped Graphene Oxide Dots-Based "Turn-OFF" H2O2, Au(III), and "Turn-OFF–ON" Hg(II) Sensors as Logic Gates and Molecular Keypad Locks". ACS Omega. 4 (6): 10702–10713. doi:10.1021/acsomega.9b00858. PMC   6648105 . PMID   31460168.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.