scholarly journals Self-assembly of a terbium(III) 1D coordination polymer on mica

2019 ◽  
Vol 10 ◽  
pp. 2440-2448 ◽  
Author(s):  
Quentin Evrard ◽  
Giuseppe Cucinotta ◽  
Felix Houard ◽  
Guillaume Calvez ◽  
Yan Suffren ◽  
...  

The terbium(III) ion is a particularly suitable candidate for the creation of surface-based magnetic and luminescent devices. In the present work, we report the epitaxial growth of needle-like objects composed of [Tb(hfac)3·2H2O] n (where hfac = hexafluoroacetylacetonate) polymeric units on muscovite mica, which is observed by atomic force microscopy. The needle-like shape mimics the structure observed in the crystalline bulk material. The growth of this molecular organization is assisted by water adsorption on the freshly air-cleaved muscovite mica. This deposition technique allows for the observation of a significant amount of nanochains grown along three preferential directions 60° apart from another. The magnetic properties and the luminescence of the nanochains can be detected without the need of surface-dedicated instrumentation. The intermediate value of the observed luminescence lifetime of the deposits (132 µs) compared to that of the bulk (375 µs) and the CHCl3 solution (13 µs) further reinforces the idea of water-induced growth.

Nanoscale ◽  
2017 ◽  
Vol 9 (36) ◽  
pp. 13707-13716 ◽  
Author(s):  
Anna D. Protopopova ◽  
Rustem I. Litvinov ◽  
Dennis K. Galanakis ◽  
Chandrasekaran Nagaswami ◽  
Nikolay A. Barinov ◽  
...  

High-resolution atomic force microscopy imaging reveals the role of fibrinogen αC regions in the early stages of fibrin self-assembly.


2019 ◽  
Author(s):  
Kevin N. Baumann ◽  
Luca Piantanida ◽  
Javier García-Nafría ◽  
Diana Sobota ◽  
Kislon Voïtchovsky ◽  
...  

The self-assembly of the protein clathrin on biological membranes facilitates essential processes of endocytosis in biological systems and has provided a source of inspiration for materials design by the highly ordered structural appearance. By mimicking the architecture of clathrin self-assemblies to coat liposomes with biomaterials, new classes of hybrid carriers can be derived. Here we present a method for fabricating DNA-coated liposomes by hydrophobically anchoring and subsequently growing a DNA network on the liposome surface which structurally mimics clathrin assemblies. Dynamic light scattering (DLS), ζ-potential and cryo-electron microscopy (cryo-EM) measurements independently demonstrate successful DNA coating. Nanomechanical measurements conducted with atomic force microscopy (AFM) show that the DNA coating enhances the mechanical stability of the liposomes relative to uncoated ones. Furthermore, we provide the possibility to reverse the coating process by triggering the disassembly of the DNA coating through a toehold-mediated displacement reaction. Our results describe a straightforward, versatile, and reversible approach for coating and stabilizing lipid vesicles by an interlaced DNA network. This method has potential for further development towards the ordered arrangement of tailored functionalities on the surfaces of liposomes and for applications as hybrid nanocarrier.


2009 ◽  
Vol 13 (07) ◽  
pp. 774-778 ◽  
Author(s):  
Byung-Soon Kim ◽  
Young-A Son

In this study, self-assembled alternating film using poly(diallyldimethylammonium chloride) (PDDAC) and meso-tetrakis(4-carboxyphenyl)porphyrin (MTCP) was prepared as a multilayer deposition on glass substrate. This preparation technique for dye deposition may provide new feasibilities to achieve the manufacture of ultrathin films for nanotechnology application. The deposition films were characterized by UV-vis spectrophotometer and Atomic Force Microscopy (AFM) analysis. The results of UV-vis spectra showed that the absorbance characteristic of the multilayer films linearly increased with an increased number of PDDAC and MTCP bilayers. AFM analysis showed the film surface was relatively uniform and the progressive growth of layers was determined.


Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 464
Author(s):  
Anastasia A. Valueva ◽  
Ivan D. Shumov ◽  
Anna L. Kaysheva ◽  
Irina A. Ivanova ◽  
Vadim S. Ziborov ◽  
...  

Muscovite mica with an amino silane-modified surface is commonly used as a substrate in atomic force microscopy (AFM) studies of biological macromolecules. Herein, the efficiency of two different protein immobilization strategies employing either (N-hydroxysuccinimide ester)-based crosslinker (DSP) or benzophenone-based photoactivatable crosslinker (SuccBB) has been compared using AFM and mass spectrometry analysis. Two proteins with different physicochemical properties—human serum albumin (HSA) and horseradish peroxidase enzyme protein (HRP)—have been used as model objects in the study. In the case of HRP, both crosslinkers exhibited high immobilization efficiency—as opposed to the case with HSA, when sufficient capturing efficiency has only been observed with SuccBB photocrosslinker. The results obtained herein can find their application in commonly employed bioanalytical systems and in the development of novel highly sensitive chip-based diagnostic platforms employing immobilized proteins. The obtained data can also be of interest for other research areas in medicine and biotechnology employing immobilized biomolecules.


Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1310 ◽  
Author(s):  
James J. Tronolone ◽  
Michael Orrill ◽  
Wonbin Song ◽  
Hyun Soo Kim ◽  
Byung Yang Lee ◽  
...  

Filamentous viruses called M13 bacteriophages are promising materials for devices with thin film coatings because phages are functionalizable, and they can self-assemble into smectic helicoidal nanofilament structures. However, the existing “pulling” approach to align the nanofilaments is slow and limits potential commercialization of this technology. This study uses an applied electric field to rapidly align the nanostructures in a fixed droplet. The electric field reduces pinning of the three-phase contact line, allowing it to recede at a constant rate. Atomic force microscopy reveals that the resulting aligned structures resemble those produced via the pulling method. The field-assisted alignment results in concentric color bands quantified with image analysis of red, green, and blue line profiles. The alignment technique shown here could reduce self-assembly time from hours to minutes and lend itself to scalable manufacturing techniques such as inkjet printing.


2012 ◽  
Vol 531-532 ◽  
pp. 600-604
Author(s):  
Hui Yong Zhang ◽  
Ji Hu ◽  
Hui Min Liu

The specific recognization between galactose group and Ricinus Communis Agglutinin (RCA) was investigated by microcantilever. The gold side of the microcantilever was covalently bound with N-galactose, RCA and asialofetuin (ASF) via mixed self assembly monolayer of 11-mercaptoundecanoic acid and 6-mercaptohexanol, respectively. After adding RCA into the flowing cell, the deflection could be observed on the N-galactose or ASF modified microcantilever. Meanwhile, the deflection could also be observed after ASF bound to the RCA modified microcantilever. In order to prove that the deflection is caused by the specific interaction between the galactose group and RCA, bovine serum albumin (BSA) was introduced into the flowing cell as control experiment and no obvious deflection was observed. The specific interaction was also confirmed by the evidence that the bound protein layer can be mechanically removed with atomic force microscopy nanolithography technology.


ChemPhysChem ◽  
2012 ◽  
Vol 13 (13) ◽  
pp. 3065-3065
Author(s):  
Sabine Stötzel ◽  
Marloes Schurink ◽  
Hans Wienk ◽  
Uschi Siebler ◽  
Monika Burg-Roderfeld ◽  
...  

2018 ◽  
Vol 115 (28) ◽  
pp. 7230-7235 ◽  
Author(s):  
Francesco Simone Ruggeri ◽  
Fabrizio Benedetti ◽  
Tuomas P. J. Knowles ◽  
Hilal A. Lashuel ◽  
Sergey Sekatskii ◽  
...  

The formation and spreading of amyloid aggregates from the presynaptic protein α-synuclein in the brain play central roles in the pathogenesis of Parkinson’s disease. Here, we use high-resolution atomic force microscopy to investigate the early oligomerization events of α-synuclein with single monomer angstrom resolution. We identify, visualize, and characterize directly the smallest elementary unit in the hierarchical assembly of amyloid fibrils, termed here single-strand protofilaments. We show that protofilaments form from the direct molecular assembly of unfolded monomeric α-synuclein polypeptide chains. To unravel protofilaments’ internal structure and elastic properties, we manipulated nanomechanically these species by atomic force spectroscopy. The single-molecule scale identification and characterization of the fundamental unit of amyloid assemblies provide insights into early events underlying their formation and shed light on opportunities for therapeutic intervention at the early stages of aberrant protein self-assembly.


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