The screencast about NanoWorld Arrow Silicon AFM probes held byNanoWorld AG CEO Manfred Detterbeck has just passed the 500 views mark. Congratulations Manfred!
NanoWorld Arrow™ AFM probes are designed for easy AFM tip positioning and high resolution AFM imaging and are very popular with AFM users due to the highly symetric scans that are possible with these AFM probes because of their special tip shape. They fit to all well-known commercial SPMs (Scanning Probe Microscopes) and AFMs (Atomic Force Microscopes). The Arrow AFM probe consists of an AFM probe support chip with an AFM cantilever which has a tetrahedral AFM tip at its triangular free end.
The Arrow AFM probe is entirely made of monolithic, highly doped silicon.
The unique Arrow™ shape of the AFM cantilever with the AFM tip always placed at the very end of the AFM cantilever allows easy positioning of the AFM tip on the area of interest.
The Arrow AFM probes are available for non-contact mode, contact mode and force modulation mode imaging and are also available with a conductive platinum iridum coating. Furthermore the Arrow™ AFM probe series also includes a range of tipless AFM cantilevers and AFM cantilever arrays as well as dedicated ultra-high frequency Arrow AFM probes for high speed AFM.
To find out more about the different variations please have a look at:
You can also find various application examples for the Arrow AFM probes in the NanoWorld blog. For a selection of these articles just click on the “Arrow AFM probes” tag on the bottom of this blog entry.
In the article “Multiswitchable photoacid–hydroxyflavylium–polyelectrolyte nano-assemblies” Alexander Zika and Franziska Gröhn describe the development of a novel reversible multi-switchable system consisting of a cationic polyelectrolyte, a hydroxyflavylium molecule (Flavy), and a photoacid.*
Ternary assemblies with sizes in the hundred-to-few hundred nanometers range in aqueous solution exhibit a multi-addressable size and shape.*
The concept exploits the unique property of the photoacid to form a more highly charged molecule and to switch the Flavy molecule in the same step when excited by light irradiation.*
Due to the network of possible reactions of Flavy, self-assembly can be accessed and triggered in a number of ways.*
While their study focused on the first proof of concept and the relation of molecular and nanoscale switching, a deeper understanding of the molecular binding effects may be considered in future studies.*
The type of the photoacid-based assembly presented in the article bears potential, for example, for delivery where the assembly property changes may provide a desirable transformable platform for tunable and smart transport.*
Figure 6 from “Multiswitchable photoacid–hydroxyflavylium–polyelectrolyte nano-assemblies” by Alexander Zika and Franziska Gröhn: Comparison of cycle I and cycle II in AFM.
*Alexander Zika and Franziska Gröhn Multiswitchable photoacid–hydroxyflavylium–polyelectrolyte nano-assemblies Beilstein J. Org. Chem. 2021, 17, 166–185. DOI: https://doi.org/10.3762/bjoc.17.17
Open Access : The article “Multiswitchable photoacid–hydroxyflavylium–polyelectrolyte nano-assemblies” by Alexander Zika and Franziska Gröhn is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0/.
In mother nature, the concept of self-assembly is vital for life, as it generates much of the functionality of living cells. It also bears great synthetic potential for the formation of versatile, switchable, and functional nanostructures.*
Noncovalent interactions can be triggered by external influences, such as the change of pH, light irradiation, thermal activation, introduction of a magnetic field, moisture, or redox response. Of high interest are light-responsive systems, for example in the fields of sensors or therapy, and, thus, it is desirable to explore novel concepts toward light-triggerable self-assembly.*
In the article “Photoresponsive Photoacid-Macroion Nano-Assemblies” Alexander Zika, Sarah Bernhardt and Franziska Gröhn present light-responsive nano-assemblies with light-switchable size based on photoacids.*
Anionic disulfonated napthol derivates and cationic dendrimer macroions are used as building blocks for electrostatic self-assembly. Nanoparticles are already formed under the exclusion of light as a result of electrostatic interactions. Upon photoexcitation, an excited-state dissociation of the photoacidic hydroxyl group takes place, which leads to a more highly charged linker molecule and, subsequently, to a change in size and structure of the nano-assemblies. The effects of the charge ratio and the concentration on the stability have been examined with absorption spectroscopy and -potential measurements.*
The influence of the chemical structure of three isomeric photoacids on the size and shape of the nanoscale aggregates has been studied by dynamic light scattering and atomic force microscopy, revealing a direct correlation of the strength of the photoacid with the changes of the assemblies upon irradiation.*
NanoWorld Ultra-Short AFM Cantilevers of the USC-F0.3-k0.3 type ( typical force constant 0.3 N/m ) were operated in tapping mode for the Atomic Force Microscopy (AFM) images presented in the article.*
Figure 1 a from “Photoresponsive Photoacid-Macroion Nano-Assemblies” by Alexander Zika et al: Assembly formation and photoresponse of the dendrimer–photoacid system at a charge ratio of r = 0.25: (a) AFM height images before (right) and after (left) irradiation. Please refer to the full article for the full figure https://www.mdpi.com/2073-4360/12/8/1746
*Alexander Zika, Sarah Bernhardt and Franziska Gröhn Photoresponsive Photoacid-Macroion Nano-Assemblies Polymers 2020, 12, 1746 DOI: 10.3390/polym12081746
Open Access : The article “Photoresponsive Photoacid-Macroion Nano-Assemblies” by Alexander Zika, Sarah Bernhardt and Franziska Gröhn is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
