MOLECULES
·
2023
·Vol. 28
·期 17
·6233
·
IF 4.6
Mengran Tang,Long Zhang,Xiaoxue Song,Long Zhao
Gold nanoparticles (AuNPs) possess remarkable optical properties and electrical conductivity, making them highly relevant in various fields such as medical diagnoses, biological imaging, and electronic sensors. However, the existing methods for modulating the optical properties of AuNPs are often under limitations such as a high cost, the complexity of detection, a narrow range of application settings, and irreversibility. In this study, we propose a novel approach to address these challenges by constructing a reversible electrochemical switch. The switch (ITO-OMAD) involves covalently linking nitroxide radicals and AuNPs (AuNPs-NO•), followed by tethering this nanocomposite to a siloxane-derived indium tin oxide (ITO) electrode. By simply electrochemically oxidizing/reducing the nitroxide units, one is able to reversibly modulate the optical properties of AuNPs at will. The surface morphology and structure of the as-prepared ITO-OMAD electrode were characterized through scanning electron microscopy (SEM) and cyclic voltammetry (CV). SEM imaging confirmed the successful anchoring of AuNPs on the ITO electrode. Electrochemical tests performed in the three-electrode system demonstrated that the local surface plasmon resonance (LSPR) of AuNPs can be reversibly regulated by alternatively imposing ± 0.5V (vs. Ag/AgCl) to the modified electrode. The development of this electrochemical switch presents a novel approach to effectively control the optical properties of AuNPs. The further exploration and utilization of this reversible electrochemical switch could significantly enhance the versatility and practicality of AuNPs in numerous applications.Keywords:gold nanoparticles;nitroxide radicals;electrochemical switch;optical regulation
研究领域:
材料科学
·
纳米技术
·
电化学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 38
·27789-27798
·
IF 3.9
Zhipeng Xu,Yongliang Qin,Dongdong Wei,Jie Jin,Long Zheng,Jie Xu,Hui Liu,Ranran Chen,Di Wang
The study of the magnetism of tightly arranged nitronyl nitroxide (NN) radicals via Au–S self-assembly is interesting. In this study, a series of radicals (S-NN, D-NN, BS-NN, BD-NN) along with two types of nanomaterials (S-NPs, D-NPs) were synthesized. NN was chosen for the magnetic units. Their structures have been successfully synthesized and analyzed. The spin magnetic properties were characterized by electron paramagnetic resonance (EPR) and superconducting quantum interference device (SQUID) measurement. The analysis revealed that the self-assembled NN formed via Au–S bonds exhibits high packing density. Furthermore, it was gratifying to observe that the AuNPs exhibit ferromagnetism after the surface modification by NN. This results in strong ferromagnetic exchange interactions of S-NPs and D-NPs : JS-NPs = +279.715 K and JD-NPs = +254.913 K, respectively.
研究领域:
材料科学
·
磁学
·
化学合成
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF COORDINATION CHEMISTRY
·
2017
·
IF 1.795
Xiang-Lan Wang,Yuan-Xia Li,Shuai-Liang Yang,Chen-Xi Zhang,Qing-Lun Wang
Complexes based on different halogen-substituted nitronyl nitroxide radicals and Cu(II), Cu3(hfac)6(NIT-Ph-F)2 (1) and Cu3(hfac)6(NIT-Ph-Cl)2 (2) (hfac = hexafluoroacetylacetonate; NIT-Ph-F = 2-(4′-fluorophenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide; NIT-Ph-Cl = 2-(4′-chlorphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), were synthesized and characterized structurally and magnetically. X-ray crystal structure analyses show that 1 and 2 have similar centrosymmetric five-spin structures consisting of three Cu(II) ions bridged by two nitroxide ligands. The Cu(II) is coordinated by six oxygens to form an octahedron, while the five coordination of the terminal Cu(II) ion is square pyramidal. Magnetic measurements reveal strong antiferromagnetic interactions between Cu(II) ions and radicals in 1 (J = −38.9 cm−1) and weak antiferromagnetic interactions between Cu(II) ions and radicals in 2 (J = −1.23 cm−1), which may be explained by the bond length of the Cu–Orad (2.468(2) Å) in 1, which is shorter than that (2.514(2) Å) in 2, and the dihedral angle (73.17(1)°) of the plane O7–O8–Cu(2)–O7A–O8A with the moiety O5–N1–C11–N2–O6 in 1 is smaller than (77.82(1)°) in 2.
研究领域:
无机化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
POLYHEDRON
·
2018
·
IF 2.067
Li-Li Zhu,Peng Hu,Jiang-Fei Cao,Yan-Hua Zhao,Yan-Ni Wu,Yi-Xuan Zhu,Yan Su,Chao Wang
Three new lanthanide-nitronyl nitroxide radical complexes [Ln(tfac) 3 (NIT-2thz)] (Ln(III) = Gd 1, Tb 2, Dy 3; tfac = trifluoroacetylacetonate; NIT-2thz = 2-(2′-thiazolyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) have been synthesized. Single crystal X-ray diffraction analyses reveal that complexes 1 – 3 are isomorphous. They all crystallized in the C2/ c space groups. Each central Ln(III) ion is eight-coordinated by three bischelate tfac ligands and one radical ligand. More specifically, NIT-2thz acts as a chelate ligand to link one Ln(III) ion through its nitrogen atom of the thiazole ring and oxygen atom of the N–O group to form a two-spin system. Magnetic studies show that Gd complex exhibits ferromagnetic Gd(III)–radical coupling, Tb and Dy complexes exhibit frequency-dependent out-of-phase signals.
研究领域:
无机化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COORDINATION CHEMISTRY
·
2017
·
IF 1.795
Jian-Ni Guo,Juan-Juan Wang,Gui-Fang Sun,Hong-Dao Li,Li-Cun Li
A novel nitronyl nitroxide NIT-thien-3-Py (2-(3-(m-pyridyl)-2-thienyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) and its Mn(II) complex [Mn(hfac)2(NIT-thien-3-Py)]2 (hfac = hexafluoroacetylacetonate) have been obtained. X-ray analysis indicates that the Mn(II) complex possesses a cyclic dimer structure in which two radical ligands link two Mn(II) ions through their NO groups and pyridine rings. The study of the magnetic data indicates that the manganese(II) ion strongly and antiferromagnetically interacts with the directly bonding NO group and there is weak ferromagnetic coupling between two Mn–NO pairs through the thiophene and pyridine rings of the radical ligand in agreement with a spin polarization mechanism.
研究领域:
无机化学
·
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
BIOMEDICINE & PHARMACOTHERAPY
·
2016
·
IF 2.326
Qiulian Chen,Limin Yang,Mei Han,Enbo Cai,Yan Zhao
Arctigenin (ARG), a nature medicine with many pharmacological activities , was poorly soluble in water and placed restriction on practical usage. Six novel arctigenin monoester derivatives were obtained from the reflux reaction with arctigenin, carboxylic acids (crotonic acid, furoic acid, 2-naphthalene acid and indol-3-acetic acid), EDCI and DMAP in dichloromethane at 60 °C for 4–6 h and their properties on nitrite scavenging assay were investigated in vitro. Based on the results, the one of the most effective derivatives, arctigenin β-indolylacetate (ARG6), was selected to study anti-tumor activity in vivo at doses of 20 and 40 mg/kg. The results showed that comparison with ARG group, ARG6 exhibited more anti-tumor activity in H22 tumor-bearing mice. Furthermore, ARG6 exhibited less damage to the liver, kidney, spleen and thymus when compared with those in positive group. Biochemical parameters of ALT , AST, BUN and Cre showed ARG6 had little toxicity to mice as well. ARG6 significantly improved serum cytokine levels of IL-2, IL-6, IFN-γ and TNF-α, and decreased VEGF compared with ARG. Moreover, H & E staining, TUNEL assay and immunohistochemical of tumor issues also indicated that ARG6 exhibited anti-tumor activity in vivo. In brief, the present study provide a method to improve ARG anti-tumor activity and provide a reference for new anti-tumor agent.
研究领域:
药理学
·
肿瘤学
·
有机化学
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 95
·92305-92315
·
IF 3.289
Yeqiang Tan,Wenqian Zhang,Yanhui Li,Yanzhi Xia,Kunyan Sui
Well-defined modification of multi-wall carbon nanotubes (MWNTs) with different molecular weight poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) was high-efficiently realized by atom transfer nitroxide radical coupling (ATNRC), which was confirmed by 1H NMR, TEM and thermogravimetric analyses (TGA). The multi-responsive behaviors of PDMAEMA modified MWNTs (MWNTs-g-PDMAEMA) suspensions were systematically investigated by rheology. Reversible thermo-thickening behavior was detected in MWNTs-g-PDMAEMA suspensions, attributing that PDMAEMA side chains aggregated to hydrophobic micro-domains physically cross-linking the polymer chains at temperatures above LCST. By the incorporation of sufficient free PDMAEMA chains (f-PDMAEMA), the suspensions with enough long grafted-chains exhibited obvious shear-thickening behaviors at high pH, which was absent in the suspensions with short grafted-chains due to steric hindrance of MWNTs as backbones. The primary mechanism of shear thickening was ascribed to the shear-induced transformation of intra-chain cross-linking to inter-chain cross-linking induced by the bridging effect of additional free-chains. Hydrophobic interaction, the amount of f-PDMAEMA chains and grafted-chain length were determined as the three vital factors of shear-thickening behaviours, which could be employed to fulfill tunable thickening/thinning responsive of MWNTs-g-PDMAEMA. In the study of self-assembly properties of MWNTs-g-PDMAEMA and the hybrid system of Au nanoparticles immobilized MWNTs-g-PDMAEMA dilute aqueous suspensions, typically dendritic fractal patterns with different details were formed in response to pH values and the concentration of NaCl, which have not been reported in the literature yet. The morphology of the self-assembled hybrid systems of Au nanoparticle immobilized MWNTs-g-PDMAEMA aggregates gradually transformed from rigid, straight and wide trunks with few side branches to soft, bent and slim trunks with many side branches as the pH value increased. The insights reported here can help to deeply understand the thickening/thinning essence and self-assembly principle of polymer brush grafted MWNTs suspensions, and guide the development of complex responsive materials with better performance.
研究领域:
材料科学
·
高分子化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
BIOMATERIALS
·
2022
·
IF 15.304
Fan Yang,Gaoyang Guo,Yunbing Wang
Cardiovascular implants made from heterogeneous tissues (HT) often clinically face premature failures such as thrombosis, inflammation, and calcification. Herein, we report a hydrogel-tissue composite exhibiting inflammation instructive release of multiple components towards preventing coagulation, promoting endothelial growth, and modulating reactive oxygen species (ROS) homeostasis . The hydrogel composed of MMP-responsive segment-crosslinked heparin mimicking polymer was loaded with a nitroxide radical via ROS cleavable boronic ester bonds and vascular endothelial growth factor (VEGF) via electrostatic attraction . Matrix metalloproteinase (MMP), which reportedly showed elevated expression in inflammation response to foreign implant degraded the hydrogel and led to the release of heparin mimicking polymer and VEGF, enhancing its anti-coagulation capacity and accelerating the growth of endothelial cells on it. In addition, the composite could sense oxidation biosignal present in the inflammation environment and subsequently release a ROS scavenger for auto-regulation of ROS balance. Subcutaneous implantation in mice suggested that the composite could steer the immune response toward an anti-inflammation state and subcutaneous implantation in rats suggested an anti-calcification effect of it. The enhanced hemocompatibility and endothelialization effects in vivo were further confirmed by the endovascular implantation of tissues via membrane-covered stent delivery. The current findings demonstrate that the incorporation of functional hydrogel into the tissue sophistically exploiting host response for controlled release of multiple active cargos is a feasible approach to boost the anticoagulant, endothelialization, anti-inflammatory, and anti-calcification functions of HT-based cardiovascular implants.
研究领域:
生物材料
·
组织工程
·
心血管科学
·
生物医学工程
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）