CATALYSIS LETTERS
·
2021
·Vol. 152
·期 4
·1215-1223
·
IF 3.186
Wang Yun,Cheng Hong,He Jia-Rui,Yao Qiao-Xia,Li Li-Ling,Liang Zhi-Hui,Li Xiang
The Knoevenagel condensation of acetylacetone and aromatic aldehyde catalyzed by lipase from porcine pancreas(PPL) and α-amylase from hog pancreas in ionic liquids and deep eutectic solvents was achieved for the first time. The highest yields is up to 96.1%. Mild reaction conditions, enhanced rates, improved yields and reagents’ reactivity which is different from that in standard organic solvents are the remarkable features observed in ionic liquids and deep eutectic solvents. Graphical Abstract
研究领域:
生物化学
·
有机化学
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2017
·
IF 2.536
Chunxi Zhao,Yang Jiao,Feng Hu,Yaling Yang
In this work, a green, simple, economical method was developed in the synthesis of fluorescent carbon dots using pork as carbon source. The as-prepared carbon dots exhibit exceptional advantages including high fluorescent quantum yield (17.3%) and satisfactory chemical stability. The fluorescence of carbon dots based nanosensor can be selectively and efficiently quenched by uric acid . This phenomenon was used to develop a fluorescent method for facile detection of uric acid within a linear range of 0.1–100 μM and 100–500 μM, with a detection limit of 0.05 μM (S/N = 3). Finally, the proposed method was successfully applied in the determination of uric acid in human serum and urine samples with satisfactory recoveries, which suggested that the new nanosensors have great prospect toward the detection of uric acid in human fluids.
研究领域:
生物化学
·
医学检测
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Kun Zheng,Xu Li,Mingjun Chen,Yi Gong,Aiwei Tang,Zhenguang Wang,Zhiren Wei,Li Guan,Feng Teng
According to mastery of solvent and reaction temperature, red, yellow, and blue emissive carbon nanodots (CNDs) with high quantum yield are successfully achieved using neutral red carbon source by solvothermal methods. The differences on the emission color of CNDs are evidently ascribed to conjugated absorption bands from n-π* transition confirmed by structural and optical characterizations. The results of quantum yield, transmission electron microscopy images, high magnification fluorescent micrographs of CNDs ethanol solution and solid-state CNDs & polyvinylpyrrolidone (CNDs&PVP) powders reveal that the obtained CNDs possess ultrahigh luminescence, favorable solubility, uniform dispersibility and well material compatibility. The bright fluorescent films were fabricated by mixing the CNDs &PVP composite powders with the epoxy. By taking advantage of these remarkable properties, the red, yellow, blue light-emitting diode was realized by combining CNDs&PVP film with a UV-LED chip. This work provides a new perspective for the explanation of the PL mechanism and the exploration of stable, high-performance, and environment-friendly multicolored CNDs-based LEDs.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF FLUORESCENCE
·
2024
·
IF 2.6
Liao Shihua,Xiang Jiamei,Wu Shaogui
This study presents a facile one-pot solvothermal synthesis of high-performance green fluorescent carbon dots (G-CDs) using o-phenylenediamine and ethylenediamine as precursors. The G-CDs show excellent optical, temporal, and chemical stability. Notably, they exhibit the highest quantum yield of 24.2% in ethanol and a strong green emission peaking at 546 nm under 440–490 nm excitation. In addition, G-CDs have outstanding salt resistance and multi-solvent compatibility. Due to its bright photoluminescence, G-CDs can be used as a secure ink for anti-counterfeiting. More remarkably, Cd 2+ ions can efficiently quench the fluorescence of G-CDs with a detection limit of 0.152 µmol/L, enabling accurate quantification of Cd 2+ in water systems. The simple synthesis of high-performance G-CDs expands their applicability in sensing and bioimaging.
研究领域:
材料科学
·
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2020
·
IF 2.87
Dan Zhao,Zhixia Zhang,CaiMao Li,Xincai Xiao,Jun Li,Xuemei Liu,Han Cheng
The preparation and application of hydrophobic carbon dots (HCDs) are now the hotspots in the field of nanomaterials. This paper reports the fast synthesis of long-wavelength-emitting HCDs (yellow-emitting, λem = 541 nm) through a solid-phase route, with l-cysteine hydrochloride anhydrous and citric acid as carbon sources and dicyclohexylcarbodiimide as a dehydrating agent, reacting at 180 °C for 40 min, with a quantum yield of 30%. The solid-phase route avoids the usage of organic reagents during the synthesis process and is thus environmentally friendly. The obtained HCDs can be simply separated into HCDs-L (less density) and HCDs-W (higher density) with differences in physical (polarity, density), optical, and chemical properties. The differences in HCDs-L, HCDs-W, and water-soluble CDs (WCDs) were compared through various characterization methods, and the synthesis and luminescence mechanisms of HCDs were investigated. Meanwhile, HCDs were employed in the fields of LED lamp production and solid fluorescent shaping material. The prepared HCDs were then modified into WCDs through the liposomal embedding method. The HCDs prepared by the new solid-phase route exhibit stable and highly efficient photoluminescence ability and will have a promising outlook in their applications in various fields.
研究领域:
纳米材料
·
化学
·
光学材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Cheng-Long Shen,Jin-Hao Zang,Qing Lou,Guang-Song Zheng,Meng-Yuan Wu,Yang-Li Ye,Jin-Yang Zhu,Kai-Kai Liu,Lin Dong,Chong-Xin Shan
Carbon nanodots (CDs) are emerging as low toxic chemiluminescent (CL) materials for new-generation cold lighting and bioimaging technology due to their tunable and efficient emissions. Nevertheless, continuous progress and efforts are still needed to improve the luminance and lifetime of the CL CDs. Here, CL quenching is observed in the CD-peroxyoxalate-hydrogen peroxide system, resulting from the water-induced aggregation and blocking effect of the electron exchange between the CDs and energetic intermediate produced in the CL reaction. A surface chemical regulation strategy is first introduced to improve the CL performance of CDs. Optimized the capped ligand species and chain length, the CDs modified by n-butylamine exhibit a CL quantum yield of 1.15 × 10 –2 einsteins mol −1 and maximal luminance of 5.11 cd m −2 , which is about 5- and 13-fold higher than the initial CDs and comparable with commercially available Rhodamine B. The enhanced performance can be explained by the decreased electron capture from water molecules generated due to the decomposition of hydrogen peroxide in the CL process.
研究领域:
材料科学
·
化学工程
·
生物成像
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 30
·13118-13124
·
IF 3.288
Long Chen,Yang Wu,Heyong Huo,Bin Tang,Yuhua Fu,Xiujie Hu,Chenghua Sun,Shuyun Zhou
Rare-earth phosphor materials have been investigated for several decades due to their high X-ray absorption coefficient and emission efficiency, but these materials tend to reveal lower resolution and packing density when fabricated in bulk. In this work, we investigated the BaFBr:Eu2+ micro/submicro/nano-crystal phosphor material prepared using a precipitation method, and we demonstrate the dependence of the optical properties of these phosphors on the annealing temperature and Eu2+ concentration. The optimum preparation conditions were determined to be an annealing temperature of 600 °C for 2 h and an Eu2+ doping concentration of 0.1 mol%, achieving a quantum yield of 53.19%. Furthermore, the average lifetime is 669 ns. In comparison with typical bulk phosphors, the shape and size distribution of the crystallites, which is about 100 nm on average, may improve the resolution and enhance the fluorescence performance. The results of this study thus offer a new strategy for the development of highly efficient storage phosphors.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2021
·
IF 3.196
Xin Feng,Xiaolin Yang,Meitong Li,Yujie Qin,Haiqing Li,Yuhong Xie
Polystyrene (PS), when used as a substrate, reacts with acetyl chloride through the Friedel–Crafts mechanism to yield fluorescent acetylated polystyrene. Different acetylated polystyrene microspheres can be obtained under different experimental conditions. The fluorescence of acetylated polystyrene is observed via fluorescence microscopy, while the quantum yield of acetylated polystyrene is determined using a steady-state transient fluorescence spectrometer. The surface morphology is observed via scanning electron microscopy, and the chemical composition and structure are investigated by Fourier infrared spectroscopy, ultraviolet spectrophotometry, X-ray diffraction, and nuclear magnetic resonance spectroscopy. Finally, the optimal reaction conditions are determined as follows: carbon disulfide (CS 2 , 35 mL), aluminium chloride (AlCl 3 , 1.161 g), acetyl chloride (AC, 1.171 g), soaking time of 12 h, temperature of 50 °C, and water bath for 5 h. Under these conditions, the acetylated polystyrene exhibited obvious fluorescence, with good fluorescence stability and coverage. Furthermore, it exhibited acid and alkali resistance, low-temperature resistance, and light resistance, and did not produce fluorescence leakage. In addition, it could be used as a tracer in organisms.
研究领域:
材料科学
·
化学工程
·
生物医学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2021
·
IF 3.599
Chenghao Li,Bin Lu,Xinyuan Wang,Yongjun Ma,Xianyan Ren,Cailin Liu,Haijun Yang
The passivation of carbon dots (CDs) are usually implemented through coupling reactions, which requires either specific functional groups on the surface of CDs or multiple steps. In this paper, we propose a feasible method to passivate CDs via in-situ free radical polymerization , which has no dependence on functional groups and thus is suitable for CDs prepared via either bottom-up or top-down route. Taking bare CDs that cut from active carbon by top-down method as an example. When putting acrylic acid , sodium methallyl sulfonate and acrylic phosphate ester as monomers into the bare CDs solution along with ammonium persulfate, stirring at room temperature for 2h, the monomers were polymerized and formed terpolymer-passivated CDs (T-CDs) of which quantum yields (QY) increased obviously. The QY of the bare CDs and the T-CDs were 0.2% and 29.1%, respectively. More interestingly, the bare CDs were found capable of constructing a redox-initiated couple with ammonium persulfate to initiate polymerization. Another example token to further approve the feasibility and universality of “in-situ free radical polymerization” passivation method is our reported poly (N-vinylcarbazole)-passivated CDs (PVK-CDs) that prepared by bottom-up method. The PVK-CDs were synthesized via thermal treatment of a mixture composed of citric acid and N-vinylcarbazole molecules at 300 °C for 2 h. During the process the citric acid was carbonized to provide pristine CDs and N-vinylcarbazole was in-situ polymerized on the surface of the pristine CDs through thermal initiation, which enhances the fluorescence QY up to 40%.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2018
·
IF 7.082
Yingbo Liu,Daiyong Chao,Liang Zhou,Yanan Li,Ruiping Deng,Hongjie Zhang
The development of high quantum yield (QY) carbon dots (CDs) is a key requirement for applications. However, how to engineer well-defined absorption band in visible region is a critical challenge to obtaining highly efficient long wavelength emissive CDs. In this work, the strategies of solvent-tuning absorption band and manganese ions-enhancing optical performance are introduced to prepare yellow emissive CDs. The utilization of toluene as solvent is a basis for achieving absorption band at 435 nm and realizing yellow emissive CDs with QY of 46%. Addition of manganese ions increase the degree of conjugated sp 2 -domians and surface states, further enhancing QY up to 68.6%. Using the yellow emissive CDs, a UV-pumped light-emitting diode (LED) was fabricated based on a 395 nm LED chip. The LED shows warm light with correlated color temperature (CCT) of 1596 K and color purity of 99%. This work provides a new insight for the development of high-quality CDs with versatile properties in pursuit of promising applications.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2018
·
IF 2.732
Yong Kuai,Changchang Zhang,Dule Hao,Xiang Liu,Liang Ma
Organic amines are apt to be oxidized in natural environment. Therefore, preparation of fluorescent materials derived from organic amines should think of the role of oxidized amines. However, this is neglected according to some reports. Herein, first generation poly(amidoamine) ( PAMAM 1.0G ) dendrimers with inherent weak photoluminescence was oxidized by ambient oxygen under heating of 180 °C for 60 min which brought an obvious enhancement of fluorescent quantum yield (QY). The oxidation was proved by both infrared and 1 H nuclear magnetic resonance. Image of transmission electron microscope (TEM) also revealed the aggregation of PAMAM 1.0G after they were suffered from the lasting heating. The enhancement of QY was also observed when the mixture of aqueous solution of PAMAM 1.0G and citric acid were disposed under the same conditions. And the QY reached as high as 64.40%, which is much higher than that of the fluorescent materials derived from sole citric acid. TEM image also exhibited the aggregation of the product. The carboxyl of the aggregated particle could be activated by N-hydroxysuccinimide and could be bonded with bovine serum albumin realizing the fluorescent labeling of BSA finally, which was demonstrated by the image of gel electrophoresis .
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
NEW CARBON MATERIALS
·
2018
·
IF 1.171
Hai-xiao Yang,He-xiang Han,Ji-tong Wang,Wen-ming Qiao,Li-cheng Ling
Novel high-carbon-yield pitches were prepared through the iodination of 1-methylnaphthalene (1-MNP) followed by dehydroiodination/polycondensation. 1-MNP was first iodinated by I 2 with the aid of I 2 O 5 , yielding mainly 1-iodo-4-MNP. Then, a thermal-dehydroiodination reaction at a comparatively low temperature of 130–180 o C was carried out to condense the iodinated products to obtain the pitches. The structures of the iodinated products and pitches were investigated by TG, GC-MS, 1H-NMR and FT-IR. Results indicated that the iodination selectivity ( S mb) reached 96.4% when 0.75 mol I 2 and 0.18 mol I 2 O 5 reacted with 1 mol 1-MNP at 60 o C for 24 h in acetic acid. Ring-hydrogenation products (tetralin, 5-methyltetralin) and methyl migration products (2-MNP, dimethylnaphthalene and trimethylnaphthalene) were found in the pitches by analyzing their methanol-soluble fractions. Dehydroiodination substantially increased the degree of polymerization and carbon yield of the pitches. The pitches exhibited high polymerization degrees (toluene soluble fraction less than 12 wt%), high carbon yields (54–66 wt%) and complicated 1-MNP molecular assembly patterns including α-α′, α-β′, β-β′, depending on dehydroiodination temperature and time. The iodination/dehydroiodination approach is simple, mild and clean for preparation of high quality pitches for high performance carbon materials.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）