JOURNAL OF FLUORESCENCE
·
2024
·
IF 2.6
Li Jiaxin,Guo Hui,Ji Weiwei,Chen Hanqi,Zhao Fengju,Yang Wei,Guo Lili,Qian Junqing
Tyrosinase inhibitors have the ability to resist melanin formation and can be used for clinical and cosmetic, so it is becoming extremely crucial to search a rapid and effective method for detecting t the activity of tyrosinase. In this study, a sensing probe based on Nitrogen-doped graphene quantum dots (N-GQDs) were prepared with carbamide and citric acid. Tyrosinase can oxidize dopamine to dopamine quinone, which can quench the fluorescence of N-GQDs based on the principle of fluorescence resonance energy transfer (FRET) process, and then the detection of tyrosinase activity can be achieved. The result demonstrated that the fluorescence intensity of N-GQDs was a linear correlation with the activity of tyrosinase. Wide detection linear ranges between 0.05 and 5 U/mL and high selectivity. The detection range of tyrosinase was 0.05 to 5 U/mL and LOD of 0.005 U/mL. According to the above, the fluorescence method established in this work could be successfully used for the trace analysis of tyrosinase and it was verified that KA is an inhibitor of tyrosinase.
研究领域:
生物化学
·
医学检测
·
材料科学
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产品关联
DOI
PubMed
高影响因子
APPLIED OPTICS
·
2026
·Vol. 65
·期 14
·4861-4870
·
IF 1.7
Xuefei Xiao,Xuefei Xiao,Xuefei Xiao,Xuefei Xiao,Xingchen Zhou,Xingchen Zhou,Xingchen Zhou,Xingchen Zhou,Zheyuan Gu,Zheyuan Gu,Zheyuan Gu,Zheyuan Gu,Jun Qian,Jun Qian,Jun Qian,Jun Qian,Min Lai,Min Lai,Min Lai,Min Lai,Yan Ma,Yan Ma,Yan Ma,Bo Liu,Bo Liu,Bo Liu,Bo Liu,Bo Liu
This study presents a fiber-optic humidity sensor based on boron and nitrogen co-doped graphene quantum dots (B,N-GQDs). Hydrophilic B,N-GQDs film was fabricated by a hydrothermal method, followed by photo-driven deposition on plastic optical fiber cores. The sensor showed a wide response range (0–85%RH) with high sensitivity (0.0072/%RH), a low detection limit (0.2%RH), high linearity (${R^2} = {0.999}$), and rapid response (2.5 s). The sensor exhibited a low hysteresis and excellent stability. Good stability and promising applications in respiration and skin moisture monitoring were also demonstrated. The sensing mechanism is attributed to humidity-dependent adsorption of water molecules by the abundant hydrophilic groups of the film. This adsorption alters the film’s refractive index and extinction coefficient, modulating the transmitted light intensity via a partial leaky-mode mechanism.
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DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2021
·
IF 6.901
Hao Wu,Zengsheng Guo,Ming Li,Guanghui Hu,Tao Tang,Jianfeng Wen,Xinyu Li,Haifu Huang
In this work, we report a strategy for enhancing the pseudocapacitive performance of MoS 2 materials by the introduction of nitrogen-doped graphene quantum dots (N-GQDs) and helical carbon tubes (HCNT). By a simple hydrothermal process, the hybrid composite (MoS 2 , N-GQDs and HCNT) were coated on the carbon cloth (CC) without any binders, which can be directly used as advanced electrode material for high-performance solid-state flexible supercapacitors . In this hybrid structure, N-GQDs are inserted between the layers of MoS 2 nanosheets , which induce and expose more active sites for pseudocapacitance contributions in MoS 2 electrode materials. Meanwhile, HCNT acts as electrically conducting bridge for enhancing the electrical conductivity of MoS 2 nanosheets and speeding up transport of electronic. As results, the hybrid composite (MoS 2 , N-GQDs and HCNT) show higher capacitive performance than pure MoS 2 . The specific capacitance of hybrid composite is high up to 3360 mF cm −2 . Further, the assembled solid-state flexible supercapacitor shows high specific capacitance of 1893 mF cm −2 , outstanding cycle life (capacitance retention of 86% after 2500 cycles), good mechanical stability and great flexibility. Our work provides a reference for the preparation of MoS 2 composites with high supercapacitive performance.
研究领域:
材料科学
·
能源存储与转换
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DOI
高影响因子
IEEE SENSORS JOURNAL
·
2018
·Vol. 19
·期 5
·1633-1639
·
IF 2.617
Ling Kong,Jie Chen,Zhiwei Chen,Jinhui Feng,Dawei Fan,Qin Wei
A new label-free aptasensor with high visible-light photoelectrochemical (PEC) activity was fabricated for the detection of AFB1 based on N-doped graphene quantum dots (N-GQDs) sensitized Zn-doped SnS2 (Zn-SnS2) nanocomposites. N-GQDs sensitized Zn-SnS2 showed an eminent PEC performance. Ascorbic acid was utilized as an efficient electron donor for scavenging photogenerated holes and inhibiting light driven electron-hole pair recombination. Under the optimum experimental conditions, the specific binding between AFB1 aptamer and AFB1 resulted in the linear decrease of photocurrent with the increase of logarithm of AFB1 concentration in the range of 0.01-20 ng mL-1 with a detection limit of 3 pg mL-1. The constructed N-GQDs sensitized Zn-SnS2 PEC aptasensor exhibited high sensitivity, low cost, and good reproducibility, which is a promising platform for the detection of other important analytes.
研究领域:
分析化学
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纳米技术
·
食品安全
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Wanfeng Wu,Yanan Qin,Yan Fang,Yukun Zhang,Shuxuan Shao,Fanxing Meng,Minwei Zhang
Currently, graphene quantum dots (GQDs) are widely used as antibacterial agents, and their effects are dependent on the reactive oxygen species (ROS) generated by photodynamic and peroxidase activities. Nevertheless, the supply of substrates or light greatly limits GQDs application. Besides, due to compensatory mechanisms in bacteria, comprehensive analysis of the molecular mechanism underlying the effects of GQDs based on cellular-level experiments is insufficient. Therefore, N-GQDs with inherent excellent, broad-spectrum antibacterial efficacy under acidic conditions were successfully synthesized. Then, via multi-omics analyses, the antibacterial mechanisms of the N-GQDs were found to not only involve generation ROS but also be associated with changes in osmotic pressure , interference with nucleic acid synthesis and inhibition of energy metabolism. More surprisingly, the N-GQDs could destroy intracellular acid-base homeostasis , causing bacterial cell death. In conclusion, this study provides important insights into the antibacterial mechanism of GQDs, offering a basis for the engineering design of antibacterial nanomaterials .
研究领域:
纳米技术
·
细菌学
·
分子生物学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
INORGANICA CHIMICA ACTA
·
2024
·
IF 2.7
Gang Liu,Sheng Xu,Wenting Li,Zhenghao Li,Lingli Liu,Shangxi Zhang,Bing Hui
In order to enhance the visible light catalytic activity of TiO 2 by broadening its photoresponse range, the TiO 2 / N -GQDs (TGs) composite catalysts with a three-dimensional hollow urchin-like structure were prepared by one-step hydrothermal method. The microstructure and photoelectric properties of the synthesized TGs composites were analyzed through a series of characterizations, and the performance in degrading organic dyes under visible light was investigated. The results demonstrated that the prepared composites effectively enhanced the visible light absorption spectrum of TiO 2 by forming heterojunction. The degradation efficiency of organic dyes could reach 95.71% under visible light irradiation for 1 h, which further increased to 99.39% after 2 h. Additionally, the photocatalytic degradation process could be effectively accelerated under acid conditions. After 5 cycles of testing, the degradation efficiency of TGs composites on organic dyes was hardly reduced, indicating that they had great visible light catalytic activity and significant reusability.
研究领域:
材料科学
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环境科学
·
光催化技术
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产品关联
DOI
高影响因子
JOURNAL OF FLUORESCENCE
·
2024
·
IF 2.6
Wang Yaru,Li Shuhuai,Ma Xionghui,Pang Chaohai,Wu Yuwei,Wang Mingyue,Li Bei,Liu Sixin
Fluorescence intensity and selective recognition ability are crucial factors in determining the analytical techniques for fluorescent probes. In this study, a core–shell fluorescent material, composed of silver nanoparticles@nitrogen-doped graphene quantum dots (Ag NPs@N/GQDs), was synthesised using mango leaves as the raw material through a thermal cracking method, resulting in strong fluorescence luminescence intensity. By employing noradrenaline as a template molecule and using a surface molecular imprinting technique, a molecularly imprinted membrane (MIP) was formed on the surface of the fluorescent material, that was subsequently eluted to obtain a highly specific, fluorescent probe capable of recognising noradrenaline. The probe captured various concentrations of noradrenaline using the MIP, which decreased the fluorescence intensity. Then a method for detecting trace amounts of noradrenaline was established. This method exhibited a linear range from 0.5 –700 pM with a detection limit of 0.154 pM. The proposed method was implemented in banana samples. Satisfactory recoveries were confirmed at four different concentrations. The method presented a relative standard deviation (RSD) of less than 5.0%.
研究领域:
分析化学
·
生物医学
·
食品科学
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DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2015
·
IF 6.409
Yong Liu,Kai Yan,Otieno Kevin Okoth,Jingdong Zhang
A photoelectrochemical (PEC) sensing platform for chloramphenicol (CAP) detection was constructed using nitrogen-doped graphene quantum dots (N-GQDs) as transducer species and label-free aptamer as biological recognition element . N-GQDs, synthesized via a facile one-step hydrothermal method , were explored to achieve highly efficient photon-to-electricity conversion under visible light irradiation . The obtained N-GQDs were characterized by transmission electron microscopy (TEM), which displayed a narrow size distribution with a mean diameter of 2.14 nm. The X-ray photoelectron spectroscopic (XPS) and Fourier transform infrared spectroscopic (FT-IR) analysis confirmed that nitrogen was successfully doped in GQDs. The UV–visible absorption spectra indicated that nitrogen doping obviously enhanced the absorption of GQDs in visible light region. As a result, the PEC activity of GQDs was promoted by nitrogen doping. Additionally, the π-conjugated structure of N-GQDs provided an excellent platform for aptamer immobilization via π–π stacking interaction. Such an aptamer/N-GQDs based sensor showed a linear PEC response to CAP concentration in the range of 10–250 nM with a detection limit (3 S/N) of 3.1 nM. The developed PEC aptasensor exhibited high sensitivity and selectivity , good reproducibility and high stability.
研究领域:
分析化学
·
环境科学
·
生物传感器
·
材料科学
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DOI
PubMed
高影响因子
NANO
·
2022
·
IF 1.438
Jie Cao,Weimin Hu,Qiuyan Li,Guo Lv,Weifeng Chen,Xiang Liu
Utilization of nonprecious metals to replace precious metals in the catalytic hydrolysis of hydrogen storage materials causes wide attention. Herein, nonprecious bimetallic nanoparticles loaded on N-doped graphene quantum dots (Co-Ni/N-GQDs) have been synthesized and applied in the hydrolysis of NH 3 BH 3 for the first time. It is demonstrated that Co-Ni/N-GQDs exhibit the obvious bimetallic synergies in the hydrolysis of NH 3 BH 3 , and the total turnover frequency (TOF) value reaches 19.94 mol H2 ⋅ mol Cat − 1 ⋅ min − 1 via the optimized design. This work first explored the catalytic performance for the nonprecious bimetallic nanoparticles loaded on N-GQDs in the hydrolysis of NH 3 BH 3 , greatly facilitating the development of both nonprecious metals and N-GQDs in the hydrogen evolution.
研究领域:
材料科学
·
催化化学
·
氢能研究
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DOI
高影响因子
BIOMATERIALS
·
2019
·
IF 10.273
Shun Deng,Ailing Fu,Muhammad Junaid,Yan Wang,Qian Yin,Chen Fu,Li Liu,Dong-Sheng Su,Wan-Ping Bian,De-Sheng Pei
Graphene quantum dots (GQDs) are well-known for its potential applications for bioimaging , biosensor, and drug carrier in biomedicine . GQDs are well characteristic of intrinsic peroxidase-like catalytic activity , which is proven effective in scavenging the free radicals, such assuperoxide anion, hydrogen peroxide, and hydroxyl radical. GQDs are also well praised for its low in vivo and in vitro toxicity. Here, we found that nitrogen-doped GQDs (N-GQDs) can strongly disturb redox-sensitive system via the selective inhibition of endogenous antioxidant enzyme activities in zebrafish. The enzyme activities or transcription levels of a battery of hemoproteins including catalase (CAT), superoxide dismutase (SOD), respiratory chain complex I, complex Ⅲ, hemoglobin (Hb), and myeloperoxidase (MPO), were significantly suppressed by N-GQDs. We also found that N-GQDs activated the cytochrome P450 monooxygenase ( e.g. cyp1a ) and the associated aryl-hydrocarbon receptor repressors ( ahrr1 and ahrr2 ) in zebrafish embryos. Compared to the ultrasmall graphene oxide (USGO), N-GQDs exhibited stronger fluorescent permeability and tissue-specific bio-accumulative effects. Taken together, our findings highlighted that exposure to N-GQDs can disrupt endogenous antioxidant enzyme activities, possibly via the competitive inhibition of electron transfer process. Our results in this study provided solid data for biosafety evaluations of various types of GQDs, and created an alert for the future biomedical applications of N-GQDs.
研究领域:
生物技术
·
毒理学
·
生物化学
·
环境科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2022
·
IF 4.831
Xin Zhan,Xiaoxiao Yu,Benmengyang Li,Rui Zhou,Qingyu Fang,Yiwei Wu
In the presence of thioglycolic acid (TGA) and under the catalysis of Fe 3+ , a simple, rapid, sensitive, selective and effective ratiometric fluorescence sensor platform based on the mixed physically blue nitrogen-doped graphene quantum dots (N-GQDs) as probe signals and orange rhodamine B as internal standard signals has been constructed for analysis of H 2 O 2 in human serum. TGA is the key factor for fluorescence response toward H 2 O 2 by N-GQDs and the mechanism is H 2 O 2 reacts speedily with TGA under the catalysis of Fe 3+ , and produces intermediate of superoxide anions ( O 2 − ), which accepts electrons from N-GQDs, and generates graphene oxide, causing the fluorescence quench of N-GQDs. Compared with N-GQDs probe, the sensitivity of the ratiometric fluorescence sensor platform of N-GQDs/rhodamine B for analysis of H 2 O 2 has been improved by nearly 5-folds. Under the optimum conditions, F λ=580nm / F λ=440nm has a good linear relationship with the concentration of H 2 O 2 and the detection limit of H 2 O 2 is 0.46 μmol/L with 3.5% RSD. The established sensor platform has been successfully used for probing H 2 O 2 in human serum with satisfactory results. The superior performance of the probe lies in its high selectivity and can be directly employed in detecting H 2 O 2 in serum samples without any sample pretreatment procedures.
研究领域:
分析化学
·
生物医学
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Shuang Han,Ruonan Sun,Le Zhao,Chen Yan,Hongtao Chu
Olaquindox (OLA) in food from its illegal use possesses great harmful effects on humans, making it important to develop sensitive, inexpensive, and convenient methods for OLA detection. This study innovatively presented a molecularly imprinted electrochemical sensor based on the synergistic effects of nitrogen-doped graphene quantum dots ( N -GQDs) and a nickel-based metal–organic framework functionalized with silver nanoparticles (Ag/Ni-MOF) for OLA detection. N -GQDs and Ag/Ni-MOF with unique honeycomb structures were sequentially modified on the glassy carbon electrode (GCE) surface to accelerate the electron transfer rate and increase the available region of the electrode. Molecularly imprinted polymers were further grown on the Ag/Ni-MOF/ N -GQDs/GCE by electropolymerization to significantly enhance the selective recognition of OLA. The constructed sensor showed excellent performance for selective OLA determination, with a wide linear range (5–600 nmol·L -1 ) and exceedingly low detection limit (2.2 nmol·L -1 ). The sensor was successfully applied to detect OLA in animal-origin food with satisfactory recoveries (96.22–101.02%).
研究领域:
分析化学
·
电化学
·
食品安全
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）