STAR Protocols
·
2023
·
IF 0
Kun Li,Chunzi Liang,Yuling Pan,Linghan Mei,Guo-Jun Zhang
Summary Here, we present a protocol for constructing an ultrasensitive biosensor for exosomal-miRNA detection. We describe steps for preparing graphene quantum dot-phosphorodiamidate morpholino oligomer hybrids, depositing them onto the reduced graphene oxide field surface, hybridizing analyte miRNA with the sensor probe, and capturing and calculating electrical signals. We also detail procedures for optimizing biosensor construction and evaluating performance. By quantifying plasma exosomal miRNA21, this protocol can identify cancer patients from healthy individuals. For complete details on the use and execution of this protocol, please refer to Li et al. 1
研究领域:
纳米技术
·
生物传感器
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分子生物学
·
癌症研究
✓ 已验证
DOI
PubMed
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 13
·7056-7067
·
IF 4.682
Guan Meng,Xuan Yang,Gao Yating,Liu Yining,Zhang Shubiao
Bacterial infections are closely associated with tumor growth and metastasis. Bacteriostasis can not only inhibit the growth and metastasis of tumors during their early diagnosis and treatment but also prevent bacterial infections after recovery. In this study, we synthesized Ag@GQD which consisted of nitrogen-doped graphene quantum dots (N-GQD) wrapped around Ag NPs through the photocatalytic reduction method. Multifunctional nanoprobes (Ag/DOX@GQD) were obtained by doxorubicin (DOX) loading. Ag@GQD exhibited high stability, low cytotoxicity, and good photoacoustic imaging performance. The effective photothermal performance of Ag@GQD enabled us to achieve the controlled release of DOX from probes using near-infrared light and pH response during the treatment of tumors using chemo-photothermal combination therapy. Results from cell-based experiments revealed that combination therapy was superior to single-drug therapy. Besides, Ag@GQD could effectively kill Staphylococcus aureus and Escherichia coli and can be expected to inhibit the growth and metastasis of tumors caused by bacteria and in reducing bacterial infections after recovery.
研究领域:
生物医学工程
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纳米医学
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肿瘤学
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微生物学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Chunlin Yang,Donghao Sun,Meigui Ou
In this paper, three kinds of nano-composites (Ho 2 O 3 /GQD, Ho 2 O 3 /N-GQD, Ho 2 O 3 /N,S-GQD) were prepared by hydrothermal synthesis, and their fluorescence and magnetic properties were characterized. The results show that elemental doping could promote the electronic Cπ-Nπ∗ leaps. In the composite process of Ho 2 O 3 and GQD or doped GQD, Ho and C are connected by O to form a new HO-O-C covalent bond. Compared with Ho 2 O 3 /GQD, the fluorescence intensity of Ho 2 O 3 /N-GQD and Ho 2 O 3 /N,S-GQD increased by 26.9 % and 61.4 % respectively, The magnetization of Ho 2 O 3 /N-GQD (VO1) (2.84emu/g) is slightly higher than that of Ho 2 O 3 /GQD (2.05emu/g). The magnetization of Ho 2 O 3 /N,S-GQD (VO2) is 3.09emu/g, about 1.5 times that of Ho 2 O 3 /GQD. After 2 h and 4 h of ultrasonic vibration treatment, the magnetic properties of doped Ho 2 O 3 /GQD were significantly improved due to the increase of oxygen-vacancy induced activation sites.
研究领域:
纳米材料科学
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 11
·期 4
·1393-1400
·
IF 8.067
Donghao Sun,Meigui Ou
A one-step hydrothermal method was used to successfully synthesize the nanocomposites with an average size of 3.15 nm of graphene quantum dots (GQDs) and gadolinium oxide (Gd2O3), and a high-density ultrasonic vibration was applied to increase the concentration of oxygen vacancies in the obtained Gd2O3/GQD nanocomposites. The structure and properties of the nanocomposites were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy and photoluminescence spectroscopy. It was found that after high-density ultrasonic dispersion for 2 h and 4 h, the fluorescence intensity of the nanocomposites was enhanced by about 42.7% and 54.6%, respectively, due to the formation of more activation sites induced by oxygen vacancies. The results of density functional theory (DFT) calculations confirmed the successful synthesis of the Gd2O3/GQD nanocomposites by Gd–O–C covalent bonds, and showed that the band gap narrowed (from 0.019 eV to 0.010 eV and 0.008 ev, respectively) for Gd2O3/GQD with more oxygen vacancies, offering an explanation to the enhancement of fluorescence intensity. Moreover, the magnetization increased (from 0.27 emu g−1 to 0.83 emu g−1) with the increasing concentration of oxygen vacancies. These results provide a favorable approach for realizing the application of the Gd2O3/GQD nanocomposites in the field of multimodal imaging.
研究领域:
材料科学
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物理学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
ANALYST
·
2025
·
IF 3.3
Jingwen Li,Yifei Li,Kai Zhang,Xiaomei Liu,Yuguo Tang,Kun Han
We developed a novel fluorescence detection method utilizing graphene quantum dots (GQDs) and manganese dioxide (MnO2) nanocomposites to enhance the sensitivity and specificity of in vitro monitoring of Bcl-2 gene expression, a key factor in tumor survival and treatment resistance. This method leverages the interplay between reduced glutathione (GSH) and hairpin DNA structures (H1 and H2) to simulate a cellular environment, enabling the redox-mediated disintegration of MnO2 nanosheets and the release of GQDs, restoring fluorescence. The presence of the Bcl-2 gene triggers a catalytic hairpin assembly (CHA) reaction, amplifying the Cy3 fluorescence signal and achieving a detection limit of 20.7 pM. The system demonstrated high specificity and stability, validated through control experiments with various DNA sequences. Optimization of key parameters, including MnO2 nanosheet concentration, GSH levels, and the ratio of hairpins H1 and H2, was critical for maximizing assay performance. The MnO2 nanosheets quench GQDs fluorescence and act as carriers for DNA probes, which are released upon reduction by GSH, mimicking intracellular redox conditions. The CHA reaction further amplifies the signal, allowing sensitive detection of low target gene levels. This biosensing platform integrates the unique properties of GQDs and MnO2 nanosheets, offering a real-time, sensitive, and selective method for monitoring Bcl-2 gene expression. This approach holds significant promise for early cancer diagnosis and personalized treatment strategies.
研究领域:
纳米技术
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生物化学
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分子生物学
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生物医学工程
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癌症研究
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYST
·
2020
·Vol. 145
·期 24
·7849-7857
·
IF 3.978
Chang Liu,Chunyu Huang,Ruixue Ma,Wanying Zhai,Jingjing Deng,Tianshu Zhou
This work demonstrates a new strategy for sensing cerebrospinal acetylcholinesterase (AChE) as a cholinergic biomarker for brain dysfunction based on graphene quantum dot (GQD)-functionalized lanthanide infinite coordination polymer (Ln-ICP) nanoparticles. The ICPs used in this work were comprised of two components, i.e. a supramolecular Ln-ICP host formed by the coordination between the GMP ligand and central metal ion Tb3+, and guest GQDs with abundant functional groups, which were utilized as antenna ligands to further sensitize the fluorescence of Tb/GMP. Upon excitation at 300 nm, the obtained GQD@Tb/GMP ICP nanoparticles exhibited enhanced green fluorescence from Tb/GMP. With the addition of Cu2+, the competitive coordination between Cu2+ and GQDs weakened the antenna effect, leading to a decrease in the fluorescence of GQD@Tb/GMP ICPs. However, in the presence of thiocholine (TCh), a thiol-containing compound hydrolyzed from acetylthiocholine (ATCh) by AChE, a stronger coordination interaction between Cu2+ and TCh occurred, resulting in the restoration of the fluorescence of GQD@Tb/GMP ICPs. Using the method established herein, the cerebrospinal AChE fluctuation of rats with acute organophosphorus pesticide (OP) poisoning or chronic Alzheimer's disease (AD) could be monitored. This study essentially provides a novel approach to realize the direct monitoring of a biomarker for brain dysfunction by regulating the competitive coordination interaction reversibly, which is critical in the early diagnosis and therapy of brain diseases.
研究领域:
纳米技术
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生物化学
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神经科学
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分析化学
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医学诊断
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2024
·
IF 8
Yufei Shi,Fuxiang Wang,Feng Gao,Jianing Kang,Jun Wu,Ziqiao Ren,Jun Zhou,Jie Dong,Wenjun Zhou,Changyu Shen
Finger distance perception plays a crucial role in enabling humanoid intelligent robotic systems to achieve smooth interaction with humans. Here, a rapidly response optical humidity sensor enabled with graphene quantum dots (GQD) for non-contact finger distance detection was proposed. The GQD was prepared through the functionalization of graphene oxide (GO) with hydrophilic groups. This modification enhances the responsiveness of GO to atmospheric humidity and promotes the deposition of conformal films of functional materials on the surfaces of optical fiber. Utilizing a light-driven coating method, the GQD was deposited onto a tilted fiber Bragg grating (TFBG) to fabricate humidity sensor. When water molecules were absorbed by GQD, the dielectric constant of GQD film was changed, causing an alteration in the intensities of the TFBG’s cladding modes. The proposed sensor shows a sensitivity of 0.032 dB/%RH with the equilibrium response and recovery time of 3.66 s and 0.92 s, respectively. The equilibrium recovery time is the fastest as far as we know. Furthermore, the sensor is capable of precisely identifying the action of a finger, such as approaching, remaining, and departing with a detection range of 0–10 mm.
研究领域:
传感技术
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材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 13
·5939-5947
·
IF 3.925
Xin Sun,Hongai Zheng,Shuangyan Jiang,Meilin Zhu,Yao Zhou,Derui Wang,Yankun Fan,Lili Hu,Daquan Zhang,Lizhi Zhang
The sulfate radical-based advanced oxidation processes (SR-AOPs) are well-established and efficient techniques for the degradation of organic pollutants. Fe2+ is used as an environmentally friendly and cost-effective catalyst for activating peroxymonosulfate (PMS) to generate sulfate radicals (SO4−˙). In some past studies, the slow process of reducing Fe3+ to Fe2+ reduced the overall reaction rate of the SR-AOP system. To overcome this challenge, in this work, we for the first time fabricated a new composite activator, FeOCl decorated by graphene quantum dots (GQDs), by a facile method for activating PMS. The experimental results demonstrate that the as-prepared FeOCl/GQD catalysts can efficiently degrade organic pollutants and kill Escherichia coli through activating PMS to generate active species. Notably, the FeOCl/(16.7 wt%) GQD composite can activate PMS to degrade organics (97.8% of RhB within 30 min) and inactivate E. coli (99.1% within 10 min) with a pH range from 3 to 11. Moreover, mechanism analyses showed that the active species were SO4−˙, ˙OH, 1O2 and O2−˙ in the FeOCl/(16.7 wt%) GQDs + PMS system, and SO4−˙ and 1O2 were proved to be the main active species. The addition of GQDs promoted the reduction of Fe3+ to Fe2+, thereby accelerating the degradation rate. Our study suggests that the promising strategy of exploiting highly efficient AOP platforms has many applications.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 8
·6516-6522
·
IF 3.289
Yan Li,Zhiyong Wu,Dou Du,Haiqing Dong,Donglu Shi,Yongyong Li
In photodynamic therapy (PDT), selective activation of the photosensitiser in tumor-relevant conditions is highly desirable to avoid side effects. In this study, a graphene quantum dot (GQD) nanosystem, composed of a redox-triggered cleavable PEG shell, was designed and developed for selective recovery of photoactive chlorine e6 (Ce6) in tumor-relevant conditions. In this unique system, the planar π conjugated structure of GQD enables efficient quenching of the photochemical properties of Ce6 in terms of fluorescence and singlet oxygen generation. Once exposed to tumor relevant glutathione (GSH), the disulfide-linked PEG shell undergoes reductive cleavage and subsequent detachment from the GQD scaffold, leading to accelerated release of Ce6 with recovered photoactivity. MTT study against HeLa cells demonstrated the high PDT efficacy of Ce6, regulated by elevated GSH concentration. The studies on in vivo/ex vivo imaging and photodynamic efficacy demonstrated superior biocompatibility of the GQD nanosystem compared with the widely reported graphene oxide (GO)-based nanovehicle. Intravenously injected GQD–SS–PEG/Ce6 showed effective suppression of tumor growth.
研究领域:
纳米医学
·
癌症治疗
·
生物材料科学
·
光化学
·
药学
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2019
·
IF 0
Sumin Wang,Jingwen Shen,Qiguan Wang,Yaru Fan,Lu Li,Kai Zhang,Lei Yang,Wenzhi Zhang,Xinhai Wang
We constructed a flexible solid-state supercapacitor based on carbon fiber cloth on which a graphene quantum dot-reduced graphene oxide solution and an aqueous polyaniline solution are alternatively sprayed. An acidic gel is used as both the electrolyte and the binder, by which two plates of electrodes are glued together, forming a symmetrical capacitor. The graphene quantum dot-reduced graphene oxide modifies the hydrophobic nature of carbon fiber cloth, which enhances the interactions between carbon fiber cloth and polyaniline. Additionally, under the strong electrostatic forces between the electropositive polyaniline and the electronegative graphene quantum dot-reduced graphene oxide, a self-assembled three-dimensional fiber-like network on carbon fiber cloth is observed. The fabricated solid-state supercapacitor shows a maximum capacitance of 82.9 mF cm–2 (1036 F g–1) at a 0.1 mA cm–2 current density referenced to the active materials on the electrodes, with a high stability of 97.7% retention after 10000 charge and discharge cycles, because of the strong interaction between polyaniline and the modified carbon fiber cloth. Moreover, the capacitance is unchanged upon bending. This facile layer-by-layer self-assembly spraying technique shows great advantages of easy operation, good controllability, and versatility and can be used universally for the fabrication of foldable and wearable photoelectric devices.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
DOI
ANALYTICAL CHEMISTRY
·
2023
·
IF 7.4
Lu Huang,Hanbing Huang,Zhuomin Zhang,Gongke Li
DNA-mediated self-assembly technology with good sensitivity and affinity ability has been rapidly developed in the field of probe sensing. The efficient and accurate quantification of lactoferrin (Lac) and iron ions (Fe3+) in human serum and milk samples by the probe sensing method can provide useful clues for human health and early diagnosis of anemia. In this paper, contractile hairpin DNA-mediated dual-mode probes of Fe3O4/Ag-ZIF8/graphitic quantum dot (Fe3O4/Ag-ZIF8/GQD) NPs were prepared to realize the simultaneous quantification of Lac by surface-enhanced Raman scattering (SERS) and Fe3+ by fluorescence (FL). In the presence of targets, these dual-mode probes would be triggered by the recognition of aptamer and release GQDs to produce FL response. Meanwhile, the complementary DNA began to shrink and form a new hairpin structure on the surface of Fe3O4/Ag, which produced hot spots and generated a good SERS response. Thus, the proposed dual-mode analytical strategy possessed excellent selectivity, sensitivity, and accuracy due to the dual-mode switchable signals from “off” to “on” in SERS mode and from “on” to “off” in FL mode. Under the optimized conditions, a good linear range was obtained in the range of 0.5–100.0 μg/L for Lac and 0.01–5.0 μmol/L for Fe3+ and with detection limits of 0.14 μg/L and 3.8 nmol/L, respectively. Finally, the contractile hairpin DNA-mediated SERS-FL dual-mode probes were successfully applied in the simultaneous quantification of iron ion and Lac in human serum and milk samples.
研究领域:
分析化学
·
纳米技术
·
生物传感
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BRITISH JOURNAL OF PHARMACOLOGY
·
2024
·
IF 6.8
Bing Shang,Yaqiong Dong,Bo Feng,Jingyan Zhao,Zhi Wang,Debbie C. Crans,Xiaoda Yang
Background and Purpose Metal-based therapeutic agents are limited by the required concentration of metal-based agents. Hereby, we determined if combination with 17β-oestradiol (E2) could reduce such levels and the therapy still be effective in type 2 diabetes mellitus (T2DM). Experimental Approach The metal-based agent (vanadyl acetylacetonate [VAC])– 17β-oestradiol (E2) combination is administered using the membrane-permeable graphene quantum dots (GQD), the vehicle, to form the active GQD–E2–VAC complexes, which was characterized by fluorescence spectra, infrared spectra and X-ray photoelectron spectroscopy. In db / db type 2 diabetic mice, the anti-diabetic effects of GQD–E2–VAC complexes were evaluated using blood glucose levels, oral glucose tolerance test (OGTT), serum insulin levels, homeostasis model assessment (homeostasis model assessment of insulin resistance [HOMA-IR] and homeostasis model assessment of β-cell function [HOMA-β]), histochemical assays and western blot. Key Results In diabetic mice, GQD–E2–VAC complex had comprehensive anti-diabetic effects, including control of hyperglycaemia, improved insulin sensitivity, correction of hyperinsulinaemia and prevention of β-cell loss. Co-regulation of thioredoxin interacting protein (TXNIP) activation by the combination of metal complex and 17β-oestradiol contributed to the enhanced anti-diabetic effects. Furthermore, a potent mitochondrial protective antioxidant, coniferaldehyde, significantly potentiates the protective effects of GQD–E2–VAC complexes. Conclusion and Implications A metal complex–E2 combinatorial approach achieved simultaneously the protection of β cells and insulin enhancement at an unprecedented low dose, similar to the daily intake of dietary metals in vitamin supplements. This study demonstrates the positive effects of combination and multi-modal therapies towards type 2 diabetes treatment. Graphical
研究领域:
药理学
·
糖尿病
·
治疗学
·
纳米技术
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）