RSC Advances
·
2015
·Vol. 5
·期 121
·99669-99677
·
IF 3.84
Junhua Li,Haibo Feng,Jianbo Jiang,Yonglan Feng,Zhifeng Xu,Dong Qian
In this work, a simple and facile protocol for the synthesis of a cobalt-ferrite magnetic nanoparticle-reduced graphene oxide nanocomposite (CoFe2O4/RGO) was achieved using an in situ chemical co-precipitation method. The characteristics of the synthesized nanocomposite were carefully investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy and electrochemical technologies, respectively. The results reveal that the abundant CoFe2O4 nanoparticles are successfully formed with particle sizes in the range of 460–510 nm and uniformly anchored on the RGO nanosheets. Due to the imbedding of CoFe2O4 nanoparticles, the nanocomposite exhibits a larger surface area and superior electrocatalytic activity towards the oxidation of levodopa, which could be used as an efficient electrocatalyst for levodopa sensing. The parameters that influence the sensing property were investigated in detailed. Under the optimum conditions, the oxidation peak currents obtained by differential pulse voltammetry and chronoamperometry show linear responses for levodopa concentrations in the ranges of 0.02–45 μM and 10–420 μM respectively, and a low detection limit of 12 nM is achieved. Compared with those of the existing analogues reported for levodopa detection, the CoFe2O4/RGO-based sensor demonstrates outstanding properties such as high sensitivity, low detection limit and wide linear dynamic range. Finally, the practical analytical application of the developed sensor was assessed by the determination of levodopa in commercially available tablets and urine samples, and satisfactory recoveries were obtained in the range of 97.8–103.2%.
研究领域:
材料科学
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分析化学
·
生物医学
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产品关联
DOI
高影响因子
Catalysts
·
2024
·Vol. 14
·期 12
·924
·
IF 3.8
Yu Yue,Guozhi Zhu,Min Liu,Yue Zhu,Weilong Ji,Xiaoqin Si,Tianliang Lu
As an important biomass resource, γ-valerolactone (GVL) shows considerable potential for applications in biofuel production, organic synthesis, polymer, and food industries. Herein, an effective method was presented for synthesizing GVL through the catalytic transfer hydrogenation (CTH) of ethyl levulinate (EL) under mild conditions. Using isopropanol as a hydrogen donor, a 100% conversion of ethyl levulinate and an 88.7% yield of GVL were achieved over 2%Zr-Beta-7d catalyst at 110 °C for 8 h. The acidic sites of synthesized Zr-Beta via hydrothermal methods easily adjusted and offered high catalytic activity and selectivity. The Lewis (L) acid sites on the zeolite serve as the active centers for the conversion of EL. Characterization results indicate that the amounts of L acid sites on Zr-Beta increased with the Zr content and crystallization time rose, thus enhancing the selectivity for GVL. Additionally, the influences of catalyst dosage, reaction temperature, and time on catalytic performance are studied, as well as calculations of kinetic parameters such as reaction rate constants and activation energies. The 2%Zr-Beta-7d catalyst retains its high performance after five cycles. The current research may present an efficient approach for the conversion of EL to GVL under mild conditions.
研究领域:
生物质化学
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催化化学
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产品关联
DOI
高影响因子
AAPS PHARMSCITECH
·
2019
·Vol. 20
·期 8
·1-13
·
IF 2.608
Qu Yang,Lai Wen-Long,Xin Yuan-Rong,Zhu Fei-Qin,Zhu Yuan,Wang Li,Ding Yue-ping,Xu Ying,Liu Hong-Fei
To enhance efficiency, convenience, and safety of Parkinson’s disease (PD) treatment for geriatric patients, an advanced suspension of Levodopa/Benserazide hydrochloride (LD/BH) has been prepared by cation-exchange resin and used to synchronize sustained release of LD and BH by optimizing coating parameters and prescription. For the purpose, LD and BH were immobilized on the surface of cation-exchange resin, respectively. Based on HPLC results, the cation-exchange resin showed high loading capacity. The studies on drug loading mechanism indicated that both drugs were immobilized by electrostatic interaction rather than physical adsorption. After PEG modification, pretreated drug-resin complexes were coated by emulsion–solvent evaporation method. In order to control drug release in a sustained manner, coating parameters of drug-resin microcapsules were optimized respectively by single-factor analysis. Further, coating prescription of the microcapsules was optimized to synchronize sustained release of LD and BH in vitro by orthogonal design. Utilizing optimal LD-resin microcapsules and BH-resin microcapsules, LD/BH suspension, containing both of them, was prepared by an optimal formulation and characterized by accelerated test and pharmacokinetic study in vivo . The accelerated test confirmed high stability of LD/BH suspension. According to pharmacokinetic results in vivo , in contrast with LD/BH commercial tablets, LD/BH suspensions did not only synchronize sustained release of both drugs but also show good bioequivalence. As LD/BH sustained release suspension can synchronize sustained release of multiple active ingredients by oral administration, the suspension presents promising oral dosage forms for geriatric patients with PD.
An advanced Levodopa/Benserazide hydrochloride (LD/BH) suspension, prepared by cation-exchange resin and optimized microencapsulation, synchronizes sustained releases of LD and BH in vivo to benefit Parkinson’s disease treatment for geriatric patients.
研究领域:
药剂学
·
神经病学
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DOI
PubMed
高影响因子
Molecular Catalysis
·
2017
·
IF 0
Ruiying Wang,Jianjia Wang,Huimin Zi,Yongmei Xia,Haijun Wang,Xiang Liu
Zr(IV)-salphen-MCM-41 was prepared by immobilizing a zirconium(IV) Schiff base complex onto the surface of MCM-41. The structural properties of the heterogeneous catalysts were characterized by FT-IR, UV, TG, XRD, SEM, TEM, BET, EDX, CO 2 -TPD, NH 3 -TPD and ICP-OES. Studies on the catalytic properties of the immobilized Zr(IV)-Schiff base complexes were performed using the reduction and cyclization of ethyl levulinate (EL) to γ-valerolactone (GVL) with isopropanol as the hydrogen source. Various reaction parameters, such as temperature, reaction time, solvent and catalyst loading were carefully investigated. The optimal conditions (GVL yield up to 90%) involved the utilization of Zr(Salphen)-MCM-41 as the catalyst in isopropanol. The key to heightened reaction performance was the incorporation of the phenolate and aniline groups in the ligands of bound to Zr. This increased the basicity of the catalyst, which subsequently enhances the efficiency of the transfer hydrogenation reported herein. Meanwhile, the immobilized catalyst can be easily separated and efficiently recycled at least five times without significant loss of activity. Finally, we proposed a plausible reaction mechanism based on experimental and characterization data.
研究领域:
化学工程
·
催化材料科学
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产品关联
DOI
Science China-Chemistry
·
2020
·Vol. 63
·期 9
·1295-1305
·
IF 6.356
Wang Xianheng,Yang Lei,Yang Peng,Guo Wancai,Zhang Quan-Ping,Liu Xianhu,Li Yiwen
Melanin-inspired polymers are currently the focus of growing interest for a wide range of applications ranging from energy to biomedical area. Whilst researchers have made numerous attempts to prepare and utilize polydopamine nanoparticles (PDA NPs), they have made limited progress in developing and discovering another typical functional mimic of natural melanin, poly (levodopa) (P(L-DOPA)) NPs, probably due to the lack of facile synthetic strategies towards satisfactory structural and functional control of melanin-like NPs. Herein, we reported a one-pot preparation method towards P(L-DOPA) NPs with good yields and controllable size/property in an aqueous solution assisted by various metal ions ( i.e. , Ni(II), Mg(II), Ca(II), Fe(III), Mn(II), Co (II), Zn(II) and Cd(II)). Interestingly, the resulting P(L-DOPA) NPs exhibited enhanced light absorption and photothermal behaviors compared with well-established PDA NPs, which can be employed to further fabricate kinds of photothermal composite actuators with promising performances such as folding, switching, and forward-moving. This study offers a facile and robust way to synthesize new synthetic melanins beyond PDA, and facilitates further functional discovery and evolution of melanin-inspired polymers and composites.
研究领域:
材料科学
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生物医学工程
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高分子化学
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2017
·
IF 4.233
Jiao Zhao,Qiang Huang,Meiying Liu,Yanfeng Dai,Junyu Chen,Hongye Huang,Yuanqing Wen,Xiaoli Zhu,Xiaoyong Zhang,Yen Wei
In this paper, a novel strategy for the preparation of poly(levodopa) functionalized MgAl-layered double hydroxide (PDOPA- f -LDH) was developed based on the modified mussel inspired chemistry. The utilization of PDOPA- f -LDH for the removal of methylene blue (MB) from aqueous solution was also examined. Taken advantage of the self-polymerization of levodopa (DOPA) in alkaline solution and the strong affinity of catechol groups to the substrate surface, the LDH was covered homogeneously by a layer of polymer coating of DOPA, leading to the functionalization toward LDH. The structure, surface morphology, thermostability and elemental composition of as-prepared PDOPA- f -LDH were investigated by the transmission electron microscope, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy. Besides, the surface charge of the PDOPA- f -LDH was also investigated using zeta potential. The effects of various parameters, including contact time, initial MB concentration, solution pH and temperature, on the adsorption of MB onto PDOPA- f -LDH were systematically investigated. Results show that the adsorption capacity of functionalized LDH at 25 °C could reach up to 102 mg/g, which is much higher than that of pure LDH in the same experimental conditions. The adsorption kinetics and isotherm of MB adsorption were studied in batch experiments. The pseudo-second-order model is found to be the best to describe the adsorption kinetics. The isotherm result shows that the Freundlich isotherm is the better-fit-isotherm model to represent the equilibrium data. The values of thermodynamic parameters, including enthalpy change Δ H 0 , entropy change Δ S 0 and Gibbs free energy change Δ G 0 , were also determined. All the Δ G 0 values are negative; the Δ H 0 and Δ S 0 values of PDOPA- f -LDH were −7.824 kJ mol −1 and −0.01562 kJ mol −1 K −1 , respectively. And the activation energy of system ( E a ) is calculated as 24.69 kJ mol −1 . The fact suggests that the MB adsorption on PDOPA- f -LDH is a spontaneous and exothermic process. These obtained results indicate that the prepared PDOPA- f -LDH could be used as an interesting adsorbent with great potential to adsorb the cationic dyeing pollutants from aqueous media.
研究领域:
材料科学
·
环境化学
·
水处理
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产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2024
·
IF 10.7
Da-Wei Zhou,Meng Yin,Yun Shen,Xiao-Xue Wang,Chen-Yu Wang,Ke-Zheng Chen,Qi Fang,Sheng-Lin Qiao
Parkinson's disease (PD) is a progressive neurodegenerative disorder marked by the loss of dopaminergic neurons and the consequent decline in motor and cognitive functions. The primary therapeutic agent levodopa necessitates precise dosing due to its narrow therapeutic window and complex pharmacokinetics. This study presents the development of a novel CuCoFe-LDHzyme-based sweat sensor for real-time monitoring of levodopa concentration in PD patients. Employing differential pulse voltammetry (DPV) technique, the sensor demonstrates high sensitivity and selectivity, achieving a detection limit of 28.1 nM. The sensor's design allows for non-invasive, continuous monitoring, significantly enhancing patient convenience compared to traditional blood sampling methods. Through pH correction, precise quantification of levodopa in sweat is accomplished, and a strong correlation (Pearson coefficient = 0.833) with blood levodopa levels is established. The pharmacokinetic profile of levodopa is reconstructed in real-time, offering a promising tool for optimizing PD treatment regimens. This study highlights the potential of CuCoFe-LDHzyme sensors to advance personalized treatment strategies, aiming to improve the quality of life for PD patients by providing clinicians with real-time data for medication adjustments.
研究领域:
神经学
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药理学
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生物传感器
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2016
·Vol. 163
·期 9
·H757
·
IF 3.014
Xiaokun Xu,Zhihui Zhu,Na Liu,Yanfang Li,Xiao Li,Lian Liu,Mi Lin,Jianguo Wang
The intramolecular cyclization step of oxidized catecholamines is crucial for neuromelanin (NM) and polydopamine (PDA). The product of the cyclization reaction of catecholamines has electrochemical activity, and its anodic and cathodic peaks occur at a more negative position than that of catecholamines. Moreover, in low pH, the amine group is protonated to a considerable extent; thus, the cyclization reaction is precluded. Our cyclic voltammetric results show that, in dilute buffer solution, the buffer concentration promotes the extent of the cyclization reaction of dopamine (DA), levodopa (L-D), and adrenaline (AD). A buffer component accepts the protons released by oxidized catecholamines, which suppresses the pH decrease near the electrode surface and protonation of amine group. Ascorbic acid (AA) more significantly inhibits the cyclization reaction of oxidized DA than those of L-D and AD. AA reduces catecholamine–quinone, and the cyclization rate constant of oxidized DA is smaller than those of L-D and AD. Consequently, buffer capacity and AA can be used to regulate the synthesis of NM and PDA.
研究领域:
生物化学
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神经科学
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材料科学
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DOI
高影响因子
MICROCHIMICA ACTA
·
2024
·Vol. 191
·期 8
·1-10
·
IF 5.3
Huang Shuo,Zhang Haopeng,Gao Xin,Su Hang,Lan Jingming,Bai He,Yue Hongyan
It is crucial to accurately and rapidly monitor the levodopa (LD) concentration for accurate classification and treatment of dyskinesia in Parkinson’s disease. In this paper, 3D graphene foam (GF) with a highly conductive network is obtained by chemical vapor deposition. 3D GF serves as the substrate for hydrothermal in situ growth of tapered cross-linked ZnO nanowire bundle arrays (ZnO NWBAs), enabling the development of a highly sensitive detection platform for LD. The formation mechanism of a tapered cross-linked ZnO nanowire bundle arrays on 3D GF is put forward. The integration of 3D GF and ZnO NWBAs can accelerate the electron transfer rate and increase the contact area with biomolecules, resulting in high electrochemical properties. The electrode composed of ZnO NWBAs on 3D GF exhibits significant sensitivity (1.66 µA·µM −1 ·cm −2 ) for LD detection in the concentration range 0–60 µM. The electrode is able to rapidly and specifically determine LD in mixed AA or UA solution. The selectivity mechanism of the electrode is also explained by the bandgap model. Furthermore, the successful detection of LD in serum demonstrates the practicality of the electrode and its great potential for clinical application.
研究领域:
材料科学
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医学
·
生物传感器
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产品关联
DOI
PubMed
高影响因子
BIOMACROMOLECULES
·
2024
·
IF 5.5
Xianheng Wang,Jianhua Zhang,Lei Yang,Tianyou Wang,Gaigai Duan,Zhipeng Gu,Yiwen Li
In the current years, polydopamine nanoparticles (PDA NPs) have been extensively investigated as an eumelanin mimic. However, unlike natural eumelanin, PDA NPs contain no 5,6-dihydroxyindole-2-carboxylic acid (DHICA)-derived units and may be limited in certain intrinsic properties; superior eumelanin-like nanomaterials are still actively being sought. Levodopa (l-DOPA) is a natural eumelanin precursor and expected to convert into DHICA and further remain within the final product through covalent or physical interactions. Herein, poly(levodopa) nanoparticles [P(l-DOPA) NPs] were synthesized with the assistance of zinc oxide as a supplement to synthetic eumelanin. This study found that P(l-DOPA) NPs had ∼90% DHICA-derived subunits on their surface and exhibited superior antioxidant activity compared to PDA NPs due to their looser polymeric microstructure. Benefitting from a stronger ROS scavenging ability, P(l-DOPA) NPs outperformed PDA NPs in treating cellular oxidative stress and acute inflammation. This research opens up new possibilities for the development and application of novel melanin-like materials.
研究领域:
生物医学工程
·
药理学
·
纳米医学
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产品关联
DOI
PubMed
高影响因子
TALANTA
·
2020
·
IF 5.339
Jinhua Liu,Changpeng Zou,Can Chen,Haixiao Fang,Qiong Wu,Haidong Yu,Jixin Zhu,Lin Li,Sheng Yang,Wei Huang
Topochemical assembly carbon materials with unique structure rarely investigated and reported. Herein, we demonstrate the feasibility of using topochemical assembly levodopa nanoparticles with dendritic structure (LNDS) network as a new high-performance biosensing platform based on noncovalent functionalization of LNDS with a fluorescent oligonucleotide . The proposed platform is dependent on the competition of π-π stacking and electrostatic repulsion interactions between LNDS and fluorescent oligonucleotide. The obtained LNDS with 96.1% quenching efficiency is synthesized by using levodopa as the single precursor by natural oxidation or microwave irradiation . The constructed platform can be used for simple and efficient probing single-nucleotide polymorphisms (SNPs) and cDNA by fluorescence restoration with a highly sensitivity and selectivity , remarkably superior to those based on graphenes. Additionally, an aptasensor is further constructed for small molecule ATP detention in serum with a low detection limit of 4 μM. To the best of our knowledge, this is the first attempt to use LNDS to design a biosensing platform, and therefore opens possibilities for new types of nanoparticle-based molecule approaches, and sequencing technologies.
研究领域:
生物传感
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材料科学
·
分子生物学
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DOI
PubMed
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Yanru Fan,Bingxu Feng,Yu Huang,Xiaoquan Lu
In this paper, the interface between two immiscible electrolyte solutions (ITIES) is adopted as the bionic interface model to investigate the interfacial electron transfer (ET) process of levodopa by using thin-layer cyclic voltammetry. Three zinc porphyrins with a systematic variation in structure are used as the reactants in the organic phase for the supply of varied overall driving forces at the ITIES. The consecutive two-step ET reactions between levodopa and three zinc porphyrins with the corresponding ET rate constants are evaluated precisely. The relationship between the interfacial ET rate constants and the overall driving force are also studied. It is found that the ET kinetics of the bimolecular reactions at the ITIES obeys the Marcus theory in a wide potential region. The results of this work will assist in our understanding of the interfacial electron-transfer process of levodopa in vivo.
研究领域:
生物医学工程
·
分子药理学
·
电化学
·
神经化学
·
药物代谢
·
生物物理化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）