Self-assembled PCBM bilayers on graphene and HOPG examined by AFM and STM

In the article «Self-assembled PCBM bilayers on graphene and HOPG examined by AFM and STM” Yanlong Li, Chuanhui Chen, John Burton, Kyungwha Park, James R Heflin and Chenggang Tao demonstrate that PCBM molecules self-assemble into bilayer structures on graphene and HOPG substrates. They used Atomic Force Microscopy (AFM) and Scanning Tunneling Microscopy (STM), and analyzed the observed morphology by comparison to molecular models.*

The AFM measurements were carried out in a dark environment. NanoWorld™ Pointprobe® NCST AFM probes were used in soft tapping mode and simultaneous height and phase images were acquired and reproduced across multiple samples.*

The results of this study shed light on improvement of the energy efficiency in solar cells containing graphene and organic molecules, by increasing the donor–acceptor interface area and could provide valuable insight into fabrication of new hybrid, ordered structures for applications to organic solar cells.*

Figure 5. from “Self-assembled PCBM bilayers on graphene and HOPG examined by AFM and STM” by Yanlong Li et al.: AFM images of PCBM bilayer and size distributions of holes at different conditions. (a) AFM image of a PCBM bilayer before annealing. (b) AFM image of a PCBM bilayer after annealing at 140 °C. (c) AFM image of a PCBM bilayer after annealing at 160 °C. (d) Area distribution histogram of holes (without PCBM area) obtained from measurements of the area of holes in AFM images of before (green) and after annealing at 140 °C (dark red) and 160 °C (dark blue). Monolithic silicon cantilevers (NCST, NANO WORLD) with a spring constant of 7.4 N m−1, first longitudinal resonance frequencies between 120 and 205 kHz, and nominal tip radius of 8 nm were employed in soft tapping mode. Simultaneous height and phase images were acquired and reproduced across multiple samples.
Figure 5. from “Self-assembled PCBM bilayers on graphene and HOPG examined by AFM and STM” by Yanlong Li et al.: AFM images of PCBM bilayer and size distributions of holes at different conditions. (a) AFM image of a PCBM bilayer before annealing. (b) AFM image of a PCBM bilayer after annealing at 140 °C. (c) AFM image of a PCBM bilayer after annealing at 160 °C. (d) Area distribution histogram of holes (without PCBM area) obtained from measurements of the area of holes in AFM images of before (green) and after annealing at 140 °C (dark red) and 160 °C (dark blue).

*Yanlong Li, Chuanhui Chen, John Burton, Kyungwha Park, James R Heflin, Chenggang Tao
Self-assembled PCBM bilayers on graphene and HOPG examined by AFM and STM
Nanotechnology, Volume 29, Number 18 (2018)
DOI: https://doi.org/10.1088/1361-6528/aab00a

Open Access The article “Self-assembled PCBM bilayers on graphene and HOPG examined by AFM and STM” by Yanlong Li et al. is licensed under a Creative Commons Attribution 3.0 International License. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. To view a copy of this license, visit https://creativecommons.org/licenses/by/3.0/

Mussel adhesion is dictated by time-regulated secretion and molecular conformation of mussel adhesive proteins

We have a month with “R” again and the shellfish season has started in the Northern Hemisphere. So we’d like to share the Nature Communications article by Petrone et. al “Mussel adhesion is dictated by time-regulated secretion and molecular conformation of mussel adhesive proteins” with you.
A NanoWorld Pointprobe® NCSTR AFM probe was used for the AFM images in this paper. This AFM probe is designed to give extra stability and accuracy during soft tapping mode imaging in order to produce higher quality AFM images while minimizing sample damage.

Supplementary Figure 16 from Petrone et. al "Mussel adhesion is dictated by time-regulated secretion and molecular conformation of mussel adhesive proteins": Atomic Force Microscopy (AFM) of mussel adhesive proteins on mica. AFM images of dry Pvfp-3α and Pvfp-5β adsorbed from 0.02 mg ml-1 solution in 5% acetic acid and 0.25 MO3 on mica. After 20 min adsorption, the mica surfaces were washed with protein -free buffer, and the AFM images show the homogenous distribution of the resulting adsorbed proteins. The height profiles for both proteins are shown in the graphs below, corresponding to the dotted red and blue lines in the respective AFM images (see black arrows).
Supplementary Figure 16 from Petrone et. al “Mussel adhesion is dictated by time-regulated
secretion and molecular conformation of mussel adhesive proteins”:
Atomic Force Microscopy (AFM) of mussel adhesive proteins on mica. AFM images of dry Pvfp-3α and Pvfp-5β adsorbed from 0.02 mg ml-1 solution in 5% acetic acid and 0.25 MO3 on mica. After 20 min adsorption, the mica surfaces were washed with protein -free buffer, and the AFM images show the homogenous distribution of the resulting adsorbed proteins. The height profiles for both proteins are shown in the graphs below, corresponding to the dotted red and blue lines in the respective AFM images (see black arrows).

Luigi Petrone, Akshita Kumar, Clarinda N. Sutanto, Navinkumar J. Patil, Srinivasaraghavan Kannan, Alagappan Palaniappan, Shahrouz Amini, Bruno Zappone, Chandra Verma, Ali Miserez
Mussel adhesion is dictated by time-regulated secretion and molecular conformation of mussel adhesive proteins
Nature Communications volume 6, Article number: 8737 (2015)
DOI https://doi.org/10.1038/ncomms9737

Please follow this external link for the full article: https://rdcu.be/5vcI

The article by Petrone, L.et al. “Mussel adhesion is dictated by time-regulated secretion and molecular conformation of mussel adhesive proteins” is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/