石墨烯量子點的定義
石墨烯量子點(Graphene Quantum Dots, GQDs)是橫向尺寸小于50 nm、厚度為0.5-1.0nm的石墨烯(圖1)。石墨烯量子點的制備由top-down和bottom-up兩種途徑,top-down方法主要以石墨烯或石墨為前驅(qū)體通過化學、電化學或物理法將橫向尺寸減小到幾個納米,bottom-up方法主要以含苯環(huán)的小分子通過水熱、高溫氣相沉積或電化學合成等方法實現(xiàn)幾個納米的量子點。
圖1?石墨烯量子點的表征
(a)石墨烯量子點的TEM圖像(插圖為石墨烯量子點的橫向尺寸分布)
(b)石墨烯量子點高分辨TEM圖像
(c)石墨烯量子點的AFM圖像及對應高度分析。Chem. Mater.,?2015, 27, 2004-2011.
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石墨烯量子點的物性
化學穩(wěn)定性方面,石墨烯量子點具有石墨烯的sp2構型原子排列結(jié)構,在化學穩(wěn)定性方面,石墨烯量子點具有較之于其它量子點材料所不具備的化學穩(wěn)定性,能夠承受強酸、強堿和較高溫度的極端環(huán)境。
帶隙性質(zhì)方面,石墨烯是一種零帶隙類半導體材料,當石墨烯的橫向尺寸減小到量子尺度(<100 nm)時,石墨烯中的π電子發(fā)生局域化,其帶隙隨之打開,通過尺寸調(diào)控、形貌調(diào)控、邊緣結(jié)構調(diào)控及摻雜等手段,石墨烯量子點的帶隙可實現(xiàn)從0?eV 到5 eV之間的寬幅調(diào)制。
光學性質(zhì)方面,石墨烯量子點具有顯著的光致發(fā)光性能,其具有高熒光穩(wěn)定性、高抗離子干擾能力和高抗光漂白能力(圖2)。同時,通過簡單的手段對石墨烯量子點尺寸與化學結(jié)構(邊緣/表面基團修飾、晶格異質(zhì)原子摻雜)的控制可實現(xiàn)石墨烯量子點發(fā)光波長的有效調(diào)控,從而實現(xiàn)石墨烯量子點可見光全光譜發(fā)光調(diào)制。
圖2?石墨烯量子點的熒光性能
石墨烯量子點(N-GQD)
水溶液與熒光染料羅丹明B(RhB)
乙醇溶液在可見光下(左圖)及紫外光下(右圖)的照片
其中N-GQD的熒光量子產(chǎn)率為0.74,RhB的熒光量子產(chǎn)率為0.68。Part. Part. Syst. Charact., 2015, 32, 434-440
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催化性能方面,石墨烯量子點具有高比表面積及邊緣原子比例,邊緣原子的占比可以高達20%,這使得該類材料在催化過程中具有最高的暴露活性位點。這一系列優(yōu)異的界面性質(zhì)使石墨烯量子點材料在能源應用領域(鋰離子電池、超級電容器、光催化產(chǎn)氫/氧等)以及環(huán)境保護領域(光催化降解)具有極高的應用價值。
生物性能方面,石墨烯量子點作為典型的碳基半導體材料,其生物安全性較之傳統(tǒng)熒光材料(熒光染料、II-IV族量子點等)更高,具有優(yōu)異的生物相容性。同時,石墨烯量子點的小尺寸使其在細胞熒光成像中更易于進入細胞內(nèi),從而實現(xiàn)胞內(nèi)環(huán)境成像。
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石墨烯量子點的應用
發(fā)光器件
石墨烯量子點通過摻雜、表面修飾等方式對其熒光性能進行有效調(diào)控后,可用于碳基發(fā)光器件的構建(圖3),較之于傳統(tǒng)LED發(fā)光器件,石墨烯量子點為發(fā)光材料的碳基發(fā)光器件具有更好的穩(wěn)定性,同時避免了潛在的重金屬污染。
圖3?基于石墨烯量子點的高效綠光LED器件?Appl. Phys. Express, 2017, 10, 032102
光學探針
石墨烯量子點通過摻雜、表面基團修飾等手段,可實現(xiàn)離子、生物分子、自由基等的高靈敏檢測。檢出限可達10-6?M至10-12?M(圖4),該方案較之于傳統(tǒng)的檢測技術,具有更高的靈敏度和抗干擾能力。
圖4 基于Se摻雜石墨烯量子點所構建的細胞中羥基自由基-還原型谷胱甘肽氧化還原過程的熒光探針技術。Chem. Mater., 2015, 27, 2004-2011
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生物成像
石墨烯量子點兼具良好的生物相容性、穩(wěn)定性、抗干擾能力和熒光性能。因此,石墨烯量子點可作為一種理想的細胞熒光成像劑應用于細胞、組織成像(圖5)。
圖5 基于綠光N摻雜石墨烯量子點在細胞成像中的應用
(a)不同濃度N摻雜石墨烯量子點的細胞毒性
(b)可見光下N摻雜石墨烯量子點處理后的組織細胞的顯微圖像
(c)對應的熒光顯微圖像。Part. Part. Syst. Charact., 2015, 32, 434-440
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腫瘤診療
石墨烯量子點具有豐富的表面基團,通過表面靶向劑修飾、藥物擔載等手段,可實現(xiàn)基于石墨烯量子點的腫瘤診斷與靶向治療。同時,利用石墨烯量子點優(yōu)異的熒光性能,在靶向治療的同時,能夠?qū)崿F(xiàn)腫瘤組織的實時熒光監(jiān)控,實現(xiàn)全治療過程的長效可視化。
?圖6 基于綠光N摻雜石墨烯量子點的腫瘤治療方案
(a)綠光N摻雜石墨烯量子點在小鼠腫瘤包塊中的選擇性富集
(b)N摻雜石墨烯量子點與自噬調(diào)節(jié)劑連用后30天中對小鼠腫瘤模型的治療效果
(c)N摻雜石墨烯量子點與自噬調(diào)節(jié)劑連用對小鼠30天存活率的提升。Adv. Funct. Mater., 2018, 1800881
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中科院上海微系統(tǒng)所發(fā)表的石墨烯量子點相關論文列表
1.?Emancipating target-functionalized carbon dots from autophagy vesicles for visualized tumor therapy, Advanced Functional Materials?2018, 1800881.
2.?Facile and Highly Effective Synthesis of Controllable Lattice Sulfur-Doped Graphene Quantum Dots via Hydrothermal Treatment of Durian, ACS Applied Materials & Interfaces, DOI:?10.1021/acsami.7b16002.
3.?Highly Active Black TiO2/N-doped Graphene Quantum Dots Nanocomposites For Sunlight Driven Photocatalytic Sewage Treatment, ChemistrySelect?3 (2018) 201-206.
4.?Electrochemical Cutting in Weak Aqueous Electrolyte: the Strategy for Controllable and Efficient Preparation of Graphene Quantum Dots, Langmuir 34 (2018) 250-258.
5.?C3N - a 2D crystalline, hole-free, tunable-narrow-bandgap semiconductor with high on-off current ratio and ferromagnetic properties,?Advanced Materials?29 (2017) 1605625.
6.?Robust GQDs Modified Thermally Reduced Graphene Oxide Membranes for Ultrafast and Long-Term Purification of Dye-Wasted Water, Advanced?Materials?Interfaces, 4 (2017) 1700209.
7.?Insights into oxidation mechanism of sp2-sp3?hybrid carbon material: preparation of water-soluble 2D porous conductive network and detectable molecule separation, Langmuir?33 (2017) 913-919.
8.?Tunable amplified spontaneous emissionin graphene quantum dots doped cholesteric liquid crystals, Nanotechnology?28 (2017) 245202.
9.?石墨烯量子點:石墨烯材料體系中的明珠,丁古巧等,張江科技評論 3 (2017) 35-36.
10.?Carbon Dioxide?Hydrogenation?over a Metal-Free Carbon Based Catalyst,ACS Catalysis?7 (2017) 4497-4503. ?
11.?Graphene quantum dot incorporated perovskite films: passivating grain boundaries and facilitating electron extraction, Physical Chemistry Chemical Physics, 19 (2017) 6057-6063.
12.?Fabrication of centimeter-scale light emitting diode with improved performance based on fat soluble graphene quantum dots,?Applied Physics Express?10 (2017) 032102.
13.?Facile Synthesis of?Highly Graphitized Nitrogen-Doped Carbon Dots and Carbon Sheets with Solid-State White-Light Emission, Materials Letters?195 (2017) 58-61.
14.?A Metal-Free Electrocatalyst for Carbon Dioxide Reduction to Multi-Carbon Hydrocarbons and Oxygenates,?Nature Communications?7 (2016) 13869.
15.?Supramolecular recognition control of polyethylene glycol modified N-doped graphene quantum dots: tunable selectivity for alkali and alkaline-earth metal ions, Analyst?141 (2016) 1052-1059.
16.?Ultrafast adsorption and selective desorption of aqueous aromatic dyes by graphene sheets modified by graphene quantum dots, Nanotechnology?24 (2016) 245703.
17.?Green, simple and large scale synthesis of N-doped graphene quantum dots with uniform edge groups by electrochemical bottom-up synthesis, RSC Advances?6 (2016) 82648-82653.
18.?3D periodic multiscale TiO2?architecture: a platform decorated with graphene quantum dots for enhanced photoelectrochemical water splitting, Nanotechnology?27 (2016) 115401.
19.?Enhanced monolayer MoS2/InP heterostructure solar cells by graphene quantum dots, Applied Physics Letters?108 (2016) 163901.
20.?Processable aqueous?dispersions of graphene stabilized by graphene quantum dots, Chemistry of Materials 27 (2015) 218-226.
21.?Selenium?doped graphene quantum dots as an ultrasensitive redox fluorescent switch,?Chemistry of Materials, 27 (2015) 2004-2011.?
22.?Negative induction effect of graphite N on graphene quantum dots: tunable band gap photoluminescence, Journal of Materials Chemistry C, 3 (2015) 8810-8816.
23.?A new?mild, clean and high-efficient method for preparation of graphene quantum dots without by-products, Journal of Materials Chemistry B,?3 (2015) 6871-6876.
24.?Aromatic-N Doping Dominant Ultra-High Quantum Yield of Graphene Quantum Dots, Particle & Particle Systems Characterization.?32 (2015) 434-440.
25.?Graphene?Quantum Dots Coating Enhances Lithium Storage Performance of CuO Nanowires, Advanced Materials Interfaces?2 (2015) 1400499.?
26.?The emission wavelength dependent photoluminescence lifetime of the N-doped graphene quantum dots.?Applied Physics Letters?107 (2015) ?241905.
27.?Triphenylphosphine modified graphene quantum dots: spectral modulation for full spectrum of visible light with high quantum yield, RSC Advances?5(2015) 33347.?
28.?Deep Ultraviolet Emission Photoluminescence and High Luminescece Efficiency of Ferric Passivated Graphene Quantum Dots: Strong Negative Inductive Effect of Fe, Synthetic Metals,?209 (2015) 468-472.
29.?Large-scale Fabrication of Heavy Doped Carbon Quantum Dots with Tunable-photoluminescence and Sensitive Fluorescent Detection, Journal of Materials Chemistry A?2 (2014) 8660.
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中科悅達提供的石墨烯量子點產(chǎn)品規(guī)格
中科悅達(上海)材料科技有限公司針對石墨烯量子點在腫瘤診療、電致發(fā)光等領域中的應用需求開發(fā)了多樣化的石墨烯量子點產(chǎn)品,包括藍光、黃綠光、紅光水溶性石墨烯量子點粉體;水溶性氧化石墨烯量子點粉體;藍光、綠光、黃光、白光石墨烯量子點熒光粉。
同時,中科悅達(上海)材料科技有限公司針對客戶實際應用需求,可實現(xiàn)石墨烯量子點多樣化結(jié)構修飾,提供多樣化的石墨烯量子點宏量生產(chǎn)、修飾技術解決方案。
一、水溶性石墨烯量子點粉體
※?基本物性
※?光學性質(zhì)
※?主要用途
1. 腫瘤診斷、治療及診療一體化
2. 腫瘤標志物檢測試劑盒
3. 干細胞輔助治療技術開發(fā)
4. 光電轉(zhuǎn)換、熱電轉(zhuǎn)換、光催化觸媒
5. 發(fā)光涂層、電致發(fā)光器件
6. 石墨烯等二維材料水相輔助分散
7. 海水淡化、超濾
※?相關文獻
1. Advanced Functional Materials, 2018, 28 (30), 1800881.
2. Nano Letters, 2010, 10(5), 1869-1873.
3. Chemistry of Materials, 2014, 27, 218-226.
4. Chemistry of Materials, 2015, 27 (6), 2004-2011.
5. Journal of Materials Chemistry A, 2014, 2 (23), 8660-8667.
6. Journal of Materials Chemistry A, 2019, 7 (10), 5740-5747.
7. Particle & Particle Systems Characterization, 2015, 32 (4), 434-440.
8. Advanced Energy Materials, 2013, 3(8), 997-1003.? ? ?
二、石墨烯量子點熒光粉
※?基本物性
※?光學性質(zhì)
※?主要用途
1. 環(huán)保型LED熒光粉
2. 環(huán)保型高級熒光防偽油墨(用于煙酒及食品等熒光防偽技術)
3. 熒光快速檢測試紙
※?相關文獻
1. JOURNAL OF MATERIALS CHEMISTRY, 2012, 22(42), 22378-22381.
2. Particle & Particle Systems Characterization, 2016, 33(2), 70-74.
3. Nature Communications, 2018, 9, 2249.
4. Nano Today, 2014, 9(5), 590-60.
5. ACS Nano, 2013, 7(12), 11234-11241.
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