In this paper, we report the structural evolution of Bi(4.2)K(0.8)Fe(2)O(9+δ) nanobelts to BiFeO3 nanochains and the related variations in multiferroic properties. By using in situ transmission electron microscopy with comprehensive characterization, it was found that the layered perovskite multiferroic Bi(4.2)K(0.8)Fe(2)O(9+δ) nanobelts were very unstable in a vacuum environment, with Bi being easily removed. Based on this finding, a simple vacuum annealing method was designed which successfully transformed the Bi(4.2)K(0.8)Fe(2)O(9+δ) nanobelts into one-dimensional BiFeO(3) nanochains. Both the Bi(4.2)K(0.8)Fe(2)O(9+δ) nanobelts and the BiFeO3 nanochains showed multiferroic behavior, with their ferroelectric and ferromagnetic properties clearly established by piezoresponse and magnetic measurements, respectively. Interestingly, the BiFeO(3) nanochains had a larger magnetization than the Bi(4.2)K(0.8)Fe(2)O(9+δ) nanobelts. Moreover, the BiFeO(3) nanochains exhibited a surprisingly large exchange bias with small training effects. This one-dimensional BiFeO(3) multiferroic nanostructure characterized by a relatively stable exchange bias offers important functionalities that may be attractive for device applications.
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http://dx.doi.org/10.1039/c4nr03148b | DOI Listing |
Angew Chem Int Ed Engl
April 2021
Beijing National Laboratory for Molecular Science, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
Allostery can regulate protein self-assembly which further affects biological activities, and achieving precise control over the chiral suprastructures during self-assembly remains challenging. Herein, to mimic the allosterical nature of proteins, the poly(phenylacetylene) block copolymers PPA-b-PsmNap with the dynamic helical backbone were synthesized to investigate their conformational-transition-induced self-assembly. As the helical conformation of the block PsmNap spontaneously transforms from cis-transiod to cis-cisoid, the decreasing solubility of PsmNap blocks in THF induced self-assembly of PPA-b-PsmNap.
View Article and Find Full Text PDFAnal Chim Acta
December 2019
School of Chemical Sciences, University of Chinese Academy of Sciences, 19A YuQuan Road, Beijing, 100049, China. Electronic address:
In this work, the as-prepared VO nanobelts can sensitively quench the fluorescence of nitrogen-doped carbon dots (N-CDs) based on the inner filter effect (IFE). In the presence of ascorbic acid (AA), the fluorescence of N-CDs can recover through the redox reaction between VO nanobelts and AA. Meanwhile, in the presence of both alkaline phosphatase (ALP) and ascorbyl-2-phosphate (AAP), the fluorescence of N-CDs can also restore since AAP can be hydrolyzed into AA by ALP.
View Article and Find Full Text PDFBiosens Bioelectron
October 2019
Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, China. Electronic address:
This work reported a ternary quenching strategy based on electrochemiluminescence resonance energy transfer (ECL-RET) between luminol/HO system and MnO capped carbon nanospheres (MnO@C) and Mn released from the reduction of MnO and ascorbic acid (AA) consumed superoxide radical (O) for detection of insulin. To improve the ECL behavior of luminol, AuPdPt hybrid nanoparticles decorated MoS nanosheet-coated TiO nanobelt (AuPdPt-MoS@TiO) were applied to combine with luminol and primary antibodies via covalent linkage which exhibited perfectly catalysis for the electroreduction of HO. In order to sensitively detect insulin, labels MnO@C were used to anchor secondary antibodies via electrostatic interaction and inhibit the ECL intensity of luminol.
View Article and Find Full Text PDFMolecules
June 2019
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials and College of Material Science and Engineering, Center for Advanced Low-Dimension Materials, Donghua University, Shanghai 201620, China.
In this article, we report the facile synthesis, self-assembly, and characterization of shape amphiphiles (BPOSS-PDI-X) based on isobutyl-functionalized polyhedral oligomeric silsesquioxane (BPOSS), perylene tetracarboxylic diimide (PDI), and (60)fullerene (C) moieties. Firstly, an asymmetrically functionalized diblock shape amphiphile precursor (BPOSS-PDI-OH) was obtained through the one-pot reaction between perylene-3,4,9,10-tetracarboxylic dianhydride and two different amines, namely BPOSS-NH and 3-amino-1-propanol. It was further conjugated with C-COOH to give a tri-block shape amphiphile (BPOSS-PDI-C).
View Article and Find Full Text PDFChemistry
June 2015
Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Lab of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Zhong Guan Cun, Beijing, 100190 (P. R. China), Fax: (+86) 10-8261-4087.
We demonstrate that an inorganic lanthanide ion (Tb(3+)) or organic dye molecules were encapsulated in situ into diphenylalanine (FF) organogels by a general, simple, and efficient co-assembly process, which generated peptide-based hybrid nanobelts with a range of colored emissions. In the presence of a photosensitizer (salicylic acid), the organogel can serve as an excellent molecular-donor scaffold to investigate FRET to Tb(3+). More importantly, heat treatment or water induction instigated a morphology transition from nanofibers to nanobelts, after which the participation of guest molecules in the FF assembly was promoted and the stability and photoluminescence emission of the composite organogels were enhanced.
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