SENSORS
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2019
·Vol. 19
·期 3
·674
·
IF 3.031
Hong Zhai,Yunfeng Bai,Jun Qin,Feng Feng
A novel colorimetric and ratiometric fluorescence sensor was constructed by using carbon quantum dots (CQDs) and o-diaminobenzene (ODB). Unlike ODB by itself, ODB oxide (oxODB) not only emits fluorescence, but also produces ultraviolet (UV) absorption. Therefore, on the basis of the potential optical properties of ODB, glucose oxidase (Gox) and horseradish peroxidase (HRP) were introduced into a CQDs–ODB system for the quantitative oxidation of ODB. When glucose is present, it is oxidized by oxygen under the catalytic action of its oxidase to form hydrogen peroxide. Hydrogen peroxide is a strong oxidant that can rapidly oxidize ODB through the catalysis of horseradish peroxidase. oxODB can cause changes in the fluorescence ratio (I550/I446) and absorbance ratio (A/A0). At the same time, the color of the detection solution can also change under sunlight and ultraviolet lamps. Therefore, glucose can be quantitatively detected by ratiometric fluorescence and colorimetry simultaneously, and semi-quantitatively detected by observing the colors with sunlight and ultraviolet lamps of 365 nm. This increases not only the convenience but also the accuracy of detection. In addition, this sensor has good selectivity and can be used for the determination of glucose in serum, providing a new idea for the development of blood glucose sensors.Keywords:dual-mode sensor;carbon quantum dots;o-diaminobenzene;glucose
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高影响因子
MICROCHIMICA ACTA
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2019
·Vol. 186
·期 3
·1-8
·
IF 5.479
Liu Shi Gang,Luo Dan,Han Lei,Li Nian Bing,Luo Hong Qun
A hybrid material composed of guanine-rich single stranded DNA (G-rich ssDNA) and cobalt oxyhydroxide (CoOOH) nanosheets is used as a nanoprobe for fluorometric turn-on detection of ascorbic acid (AA). The CoOOH nanosheets function as a recognition component for AA. The G-rich ssDNA is used to produce a G-quadruplex, and the G-quadruplex/thioflavin T (ThT) complex acts as a fluorescent reporter. In the absence of AA, p-phenylenediamine (PPD) is oxidized to form oxPPD which has a dark red color. It causes the fluorescence of the G-quadruplex/ThT complex to be quenched. However, in the presence of AA, the CoOOH nanosheets of the nanoprobe are preferentially reduced by AA. Hence, PPD is not oxidized, and fluorescence is not quenched. A fluorometric turn-on method was developed based on these findings. It has a detection limit of 94 nM and works in the concentration range from 1 to 10 and 20 to 80 μM. This method was applied to the determination of AA in (spiked) fruit juice samples.
Schematic presentation of a fluorescent assay of ascorbic acid (AA) is established using a nanoprobe composed of guanine-rich single stranded DNA (G-rich ssDNA) and cobalt oxyhydroxide (CoOOH) nanosheets. It is based on competitive reduction of CoOOH by p-phenylenediamine (PPD) and AA. Thioflavine T (ThT) induces the formation of fluorescent G-quadruplex/ThT complex. The oxidized form of PPD (oxPPD) can quench the fluorescence via fluorescence resonance energy transfer (FRET), but AA suppresses quenching.
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高影响因子
GREEN CHEMISTRY
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2019
·Vol. 21
·期 5
·1075-1079
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IF 9.405
Yong Ni,Zhihao Bi,Hui Su,Lifeng Yan
Efficient conversion of furfural to valuable chemicals is attracting attention because it is one of the bulk feedstocks in biomass refinery. Maleic acid (MA) and fumaric acid (FA) are two types of bulk monomers that can be prepared from furfural. Here, a simple method was developed to oxidize furfural to both MA and FA in a green deep eutectic solvent (DES). DES contained oxalic acid and choline chloride (ChCl); oxalic acid worked as both the main content of the solvent and acidic catalyst for the conversion. It was found that the conversion of furfural could reach 100%, while the yield of MA and FA reached 95.7% under a mild reaction temperature of 50 °C, which provided a green and efficient route for the synthesis of valuable monomers from furfural.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
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2018
·Vol. 54
·期 4
·3144-3155
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IF 2.993
Qu Fei,Li Xiaonan,Lv Xiaoxia,You Jinmao,Han Wenli
Photoinduced electron transfer (PET) has been used as reporter in the field of photoluminescence sensors and switches, and intermolecular PET is believed to be responsible for fluorescence quenching. Herein, the emissions of Tb-MOF can be quenched effectively by protamine based on PET. Compared with conventional electrostatic attraction mechanism, this approach suffers less interference from other charged substances and has a broader linear range of protamine from 3 to 5000 ng/mL with limit of detection (LOD) 1.21 ng/mL. Subsequently, the strong binding effect of protamine toward Hep ascribed to electrostatic attraction hinders the interaction between Tb-MOF and protamine, resulting in the high emissions of framework. The detection of Hep also shows a good linear range from 0.5 to 5 μM with LOD 0.27 μM. Finally, this novel probe is also successfully applied to the determination of protamine and Hep in human serum with satisfactory results.
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高影响因子
APPLIED CATALYSIS A-GENERAL
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2018
·
IF 4.521
Zhi Cao,Ming Li,Yong Chen,Tao Shen,Chenglun Tang,Chenjie Zhu,Hanjie Ying
The widely available reagent ethylenediaminetetraacetic acid (EDTA) was used as a temperature-responsive catalyst to produce 5-hydroxymethylfurfural (HMF) from fructose. Using this catalyst, a remarkable HMF yield of 89 ± 3% was achieved in a water-MIBK biphasic system containing polyvinylpyrrolidone (PVP) and 2-butanol. The pH of the reaction system based on EDTA as a catalyst was shown to be temperature-responsive. Moreover, the EDTA catalyst could be recycled simply by cooling the reaction liquid to room temperature due to its temperature-dependent solubility in water. A slight decrease in the yield of HMF (from 89 ± 3 to 81 ± 2%) was observed after EDTA repeated use for five cycles, and a yield of 88 ± 2% was achieved again after purification of the recycled EDTA via recrystallization with NaOH/HCl. The FTIR spectrum of recycled EDTA was almost the same as that of fresh catalyst, and TG analysis showed the decomposition temperature of EDTA is about 260 °C. Furthermore, a leaching test revealed that only 4.3 ± 0.2% of the initial EDTA was lost after five-time reuse.
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高影响因子
ANALYST
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2018
·Vol. 144
·期 1
·274-283
·
IF 3.864
Xin Xing Zhang,Qiu Yan Zhu,Jiao Yang Lu,Fu Rui Zhang,Wei Tao Huang,Xue Zhi Ding,Li Qiu Xia
Sensing of pyrophosphate (PPi) is helpful to better understand many life processes and diagnose various early-stage diseases. However, many traditional reported methods based on artificial receptors for sensing of PPi exhibit some disadvantages including difficulties in designing appropriate binding sites and complicated multi-step assembly/functionalization. Thus, it is significantly important and a big challenge to know how to use a simple molecular self-assembly or an interaction system to solve the above-mentioned limits to achieve the quantitative analysis of specific substances in the system. Based on the natural connection and similarity (such as stimulus responsiveness) between sensing and logic computing, in this study, the Boolean logic tree of molecular self-assembly system based on the cobalt oxyhydroxide (CoOOH) nanoplatform is constructed and applied to organize and connect “plug and play” molecular events (fluorescent dye, acridine orange and anion, PPi). By using molecules as inputs and the corresponding fluorescence signal as the output, the CoOOH-based molecular self-assembly system can be programmed for three-input fluorescent Boolean logic computation, fluorescent three-state logic computation, detection of PPi (linear range from 50 to 6400 nM with a detection limit of 20 nM) and even for imaging in living cancer cells and in vivo (in systems such as Zebrafish and Carassius auratus). Our approach adds a new dimension for expanding molecular logic computing and sensing systems, which will not only provide more opportunities for developing novel logic computing paradigms, but also be helpful in promoting the development and applications of intelligent molecular computing and sensing systems.
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高影响因子
ANALYTICA CHIMICA ACTA
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2019
·
IF 5.256
Mei-Yuan Shi,Ming Xu,Zhi-Yuan Gu
Ultrathin two-dimensional (2D) metal-organic framework (MOF) nanosheets have attracted numerous attention due to their unparalleled advantages such as unique structures, large surface areas, good stability and high catalytic efficiency . In this paper, 2D Cu(bpy) 2 (OTf) 2 nanosheets (Cu-MOF, bpy = 4,4-bipyridine, OTf = trifluoromethanesulfonate) are first utilized to achieve the fluorescent detection for H 2 O 2 and glucose with their intrinsic peroxidase-like activity. The fluorescent biosensor Cu-MOF nanosheets were achieved by the efficient catalysis of non-fluorescent thiamine (TH) to strong fluorescent thiochrome in the presence of H 2 O 2 . With the combination of glucose oxidase , highly selective and sensitive fluorescent detection for glucose could be established with a detection limit of 0.41 μM and two separate linear ranges of 10–100 μM and 100–1000 μM, respectively. Furthermore, the developed method has been applied to human serum for the quantitative determination of glucose as a clinical diagnosis indicator of diabetes mellitus.
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高影响因子
Nanoscale
·
2019
·Vol. 11
·期 27
·13126-13138
·
IF 6.97
Yurui Zhou,Lu Li,Shenghui Li,Shufei Li,Miao Zhao,Qinghong Zhou,Xiaoqun Gong,Jin Yang,Jin Chang
Diabetic cataracts (DCs) are one of the most common ocular complications of diabetes, and easily causes blindness among diabetics. However, there are limited drugs to delay and prevent DCs. Research studies indicate that oxidative damage of the crystalline lens and nonenzymatic glycosylation of the lens protein play a key role in the pathogenesis of DCs. Hence, we developed a kind of autoregenerative redox nanoparticle, which was CeO2 NPs coated with PEG-PLGA (PCNPs). We first found that PCNPs could work not only as an antioxidant to protect lens epithelial cells from oxidative stress based on the repetitive elimination of reactive oxygen species (ROS), but also as a glycation inhibitor effectively restraining α-crystallin glycation and crosslinking, thereby keeping the lens transparent and alleviating DCs. Experimental results successfully validated the fact that the PCNPs were able to operate in eyes for a long time to attenuate lens opacity. We expect that this strategy will provide promising potential for the treatment of DCs.
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高影响因子
CARBOHYDRATE POLYMERS
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2019
·
IF 6.044
Chun-Qian Zhang,Xia Chen,Kan Ding
Dioscorea opposita Thunb. is widely used as functional foods and traditional Chinese medicine in China for its activity of regulating function of spleen and stomach. Polysaccharides may contribute to the function of regulation. To investigate structure features and bioactivities of polysaccharides from D. opposita, the rhizome of D. opposita was extracted with boiling water, yielding crude polysaccharides DOP. A novel polysaccharide named DOP0.1-S-1 was isolated from DOP by further purification. The average molecular weight of DOP0.1-S-1 was 10,000 Da and the range was around 12,000 –1,200 Da. The carbohydrate content of DOP0.1-S-1 was 100% and no protein was detected. The monosaccharide analysis showed that DOP0.1-S-1 was mostly composed of galactose. Methylation and NMR spectra analysis indicated that DOP0.1-S-1 was a 1,4-β-galactan. Bioactivity test showed that DOP0.1-S-1 could promote the growth of B. thetaiotaomicron and B. ovatus and produce the short-chain fatty acids during the utilization of the polysaccharide.
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高影响因子
Analytical Methods
·
2019
·Vol. 11
·期 12
·1697-1706
·
IF 2.378
Zhixia Yao,Zhen Li,Hanmeng Liu,Yaosheng Liu,Yujing Sun,Zhuang Li
A rapid and sensitive colorimetric strategy for the determination of ascorbic acid (AA) is presented, using amino functionalized copper metal–organic framework nanoparticles (Cu-BDC-NH2 NPs) with effective intrinsic peroxidase-like properties. In our design, Cu-BDC-NH2 NPs catalyze the H2O2 oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) generating blue-colored oxidized TMB (ox-TMB) with a significant absorbance at 655 nm in the UV-vis spectrum. AA can reduce ox-TMB, inducing a dramatic blue color fading and a decrease in absorbance. Under the optimal experimental conditions, this proposed system presents a good linear relationship (0.5–60 μM) and the detection limit is 0.15 μM. Repeatability, high selectivity and practicability are also well-studied, proving that the sensing system based on Cu-BDC-NH2 NPs can be successfully applied for colorimetric detection of AA in human serum, food and pharmaceutical samples. The designed method can provide a highly selective and sensitive optical sensing system to detect AA and establish a new platform to develop extensive applications of metal–organic framework nanoparticles with enzyme-mimetic activity in colorimetric biosensing.
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高影响因子
ENERGY & FUELS
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2019
·
IF 3.021
Ning Shi,Qiying Liu,Xiong He,Gui Wang,Ni Chen,Jiayu Peng,Longlong Ma
Hydrochars are solid byproducts formed during the liquid-phase biorefinery process and could be used to generate functional carbonaceous materials, but the detailed molecular structure and the formation mechanism are still unclear. Herein, the formation of hydrochars from liquid-phase carbonization of biomass-derived compounds including glucose, fructose, xylose, ribose, dihydroxyacetone (DHA), 5-hydroxymethylfurfural (HMF), furfural (FF), and pyruvaldehyde (PRV) in water and inert polar organic solvents ethyl acetate (EAC) and tetrahydrofuran (THF) was studied. The carbohydrates were found to generate hydrochars in both water and the organic solvents, while the HMF and FF could generate hydrochars only in water. The α-carbonyl aldehydes, including PRV, 3-deoxyglucosone, and 2,5-dioxo-6-hydroxyhexanal (DHH), formed during the decomposition of carbohydrates were proposed to be the key primary precursors for hydrochar formation. The molecular structures of the hydrochars were characterized by elemental analysis, Fourier transform infrared analysis, and solid-state 13C NMR analysis to confirm that the molecular formula of the hydrochars all could be approximately expressed as (C3H2O)n, and the molecular structures of the hydrochars all consisted of polyaromatic hydrocarbon, phenolic, furanic, and aliphatic framents and a small amount of carbonyl/carboxyl groups. The presence of the polyaromatic hydrocarbon and phenolic fragments in the hydrochars suggested that aldol condensation played a critical role for hydrochar formation. By regarding the aldol condensation of α-carbonyl aldehydes as the initial step for hydrochar formation, we deduced the polymerization routes of these α-carbonyl aldehydes and found that the α-carbonyl aldehydes all could undergo aldol condensation followed by acetal cyclization and etherification to form polymers (C3H2O)n rich in furanic framework or undergo aldol condensation followed by a 1,2-hydride shift, intramolecular aldol condensation, and dehydration to generate polymers (C3H2O)n rich in the phenolic framework. One molecular structure containing polyaromatic hydrocarbon, phenolic, furanic, and aliphatic fragments is proposed for the hydrochars.
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高影响因子
Sustainable Energy & Fuels
·
2018
·Vol. 2
·期 5
·1035-1047
·
IF 0
Junfeng Feng,Jianchun Jiang,Chung-yun Hse,Zhongzhi Yang,Kui Wang,Jun Ye,Junming Xu
Selective catalytic conversion of biomass waste for producing methyl levulinate (MLA) via directional microwave-assisted liquefaction was investigated. The goal of the study was to develop a directional liquefaction process using dielectric heating with microwave energy. The methanolysis of biomass into methyl levulinate was studied in the presence of several acid catalysts. The C6 sugar substrates in biomass were successfully converted into methyl levulinate under the optimized conditions (180 °C, 40 min) with a yield of 29.39 wt%. 5-Hydroxymethyl furfural, glucose, fructose, cellobiose, corn starch, and microcrystalline cellulose were selected as models for directional microwave-assisted liquefaction. Therefore, the possible reaction pathway of biomass to methyl levulinate could be investigated. The selective catalytic conversion of biomass was found to be highly efficient for the generation of MLA (reaching a maximum yield of approximately 30 wt%), higher than the levulinic acid yield (14 wt%) in aqueous solution under the same reaction conditions. The results suggested that directional microwave-assisted liquefaction is an effective method that can produce a high value-added fuel additive (methyl levulinate) from lignocellulosic biomass under designated reaction processes.
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