Tag: Pointprobe

Graphene Quantum Dots as Nanozymes for Electrochemical Sensing of Yersinia enterocolitica in Milk and Human Serum

Yersinia enterocolitica is a gram-negative bacillus shaped bacterium that leads to a zootonic disease called yersiniosis. The infection is demonstrated as mesenteric adenitis, acute diarrhea, terminal ileitis, and pseudoappendicitis. Rarely, it can even result in sepsis. According to the 2017 report of the European Food Safety Authority (EFSA) and European Centre for Disease Prevention and Control (ECDC), Y. enterocolitica has been realized as the third most common foodborne-zoonotic disease after campylobacteriosis and salmonellosis in the European Union.*

Several studies suggested that the bacterium cannot survive after a proper pasteurization process, although contrary findings were also reported. The quick and accurate detection of the bacterium from food products or the body fluids of infected individuals is, therefore, important.*

Biosensors offer strong alternatives to the already existing detection techniques for rapid and sensitive quantification of Y. enterocolitica.*

In their paper “Graphene Quantum Dots as Nanozymes for Electrochemical Sensing of Yersinia enterocolitica in Milk and Human Serum” Sumeyra Savas and Zeynep Altintas describe a novel immunosensor approach using graphene quantum dots (GQDs) as enzyme mimics in an electrochemical sensor set up to provide an efficient diagnostic method for Y. enterecolitica.*

The developed method can be used for any pathogenic bacteria detection for clinical and food samples without pre-sample treatment. Offering a very rapid, specific and sensitive detection with a label-free system, the GQD-based immunosensor can be coupled with many electrochemical biosensors.*

The bare gold, GQD-laminated, and antibody-immobilized sensor surfaces were characterized by atomic force microscopy (AFM) using NanoWorld Pointprobe® NCLR AFM probes.*

Figure 4 from “Graphene Quantum Dots as Nanozymes for Electrochemical Sensing of Yersinia enterocolitica in Milk and Human Serum“ by S. Savas and Z. Altintas:
AFM analysis of bare (A), GQD-laminated (B), and antibody-immobilized (C) sensor surfaces.

*Sumeyra Savas and Zeynep Altintas
Graphene Quantum Dots as Nanozymes for Electrochemical Sensing of Yersinia enterocolitica in Milk and Human Serum
Materials 2019, 12(13), 2189
DOI: https://doi.org/10.3390/ma12132189

Please follow this external link to read the full article: https://www.mdpi.com/1996-1944/12/13/2189

Open Access The article “Graphene Quantum Dots as Nanozymes for Electrochemical Sensing of Yersinia enterocolitica in Milk and Human Serum “ by Sumeyra Savas and Zeynep Altintas 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/.

A Short Peptide Hydrogel with High Stiffness Induced by 310‐Helices to β‐Sheet Transition in Water

In the article “A Short Peptide Hydrogel with High Stiffness Induced by 310‐Helices to β‐Sheet Transition in Water” by Shu Hui Hiew, Harini Mohanram, Lulu Ning, Jingjing Guo, Antoni Sánchez‐Ferrer, Xiangyan Shi, Konstantin Pervushin, Yuguang Mu, Raffaele Mezzenga and Ali Miserez, a short biomimetic peptide composed of eight amino acid residues derived from squid sucker ring teeth proteins is demonstrated to form hydrogel in water without any cross‐linking agent or chemical modification and exhibits a stiffness on par with the stiffest peptide hydrogels.
Their study broadens the range of secondary structures available to create supramolecular hydrogels, and introduces 310‐helices as transient building blocks for gelation via a 310‐to‐β‐sheet conformational transition.*

The AFM images presented in this study were obtained in soft tapping mode using NanoWorld Pointprobe® NCSTR AFM probes.

Figure 1 from «A Short Peptide Hydrogel with High Stiffness Induced by
310‐ Helices to β‐Sheet Transition in Water” by Shu Hui Hiew et al.
Structural features and physico‐chemical properties of GV8 peptide hydrogel observed with time‐series spectroscopy measurements during gelation
b) AFM amplitude profile of dried GV8 hydrogel with fibers of ≈6–10 nm height.

*Shu Hui Hiew, Harini Mohanram, Lulu Ning, Jingjing Guo, Antoni Sánchez‐Ferrer, Xiangyan Shi, Konstantin Pervushin, Yuguang Mu, Raffaele Mezzenga, Ali Miserez
A Short Peptide Hydrogel with High Stiffness Induced by 310‐Helices to β‐Sheet Transition in Water
Advanced Science 2019, 1901173
Doi: https://doi.org/10.1002/advs.201901173

Please follow this external link to read the full article: https://onlinelibrary.wiley.com/doi/full/10.1002/advs.201901173

Open Access: The article « A Short Peptide Hydrogel with High Stiffness Induced by 310‐Helices to β‐Sheet Transition in Water » ” by Shu Hui Hiew, Harini Mohanram, Lulu Ning, Jingjing Guo, Antoni Sánchez‐Ferrer, Xiangyan Shi, Konstantin Pervushin, Yuguang Mu, Raffaele Mezzenga and Ali Miserez 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 thirdparty 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/.

    New Insights in the Ion Beam Sputtering Deposition of ZnO-Fluoropolymer Nanocomposites

    Surface modification treatments able to confer antistain/antibacterial properties to natural or synthetic materials are receiving increasing attention among scientists. Ion beam co-sputtering (IBS) of zinc oxide (ZnO) and poly-tetrafluoroethylene (PTFE) targets allows for the preparation of novel multifunctional coatings composed of antimicrobial ZnO nanoparticles (NPs) finely dispersed in an antistain PTFE polymeric matrix.*

    In the article “New Insights in the Ion Beam Sputtering Deposition of ZnO-Fluoropolymer Nanocomposites” Maria Chiara Sportelli, Marco Valentini, Rosaria Anna Picca, Antonella Milella, Angelo Nacci, Antonio Valentini and Nicola Cioffi describe the use of X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and transmission electron microscopy (TEM) for the characterization of the IBS deposited coatings in order to obtain information on the materials’ surface composition, with deep insight into the nanocoatings’ morphology as a function of the ZnONP loadings.*

    The AFM micrographs shown in this article were acquired on 150-nm-thick films in dynamic (“tapping”) mode, in air, using NanoWorld Pointprobe® NCL AFM probes.

    Figure 2 from “New Insights in the Ion Beam Sputtering Deposition of ZnO-Fluoropolymer Nanocomposites” by Maria Chiara Sportelli et al.: Atomic force microscopy (AFM) micrographs of ZnO-CFx nanocomposites having an inorganic phase volume fraction of φ = 0.05 (a–a’), φ = 0.10 (b–b’), and φ = 0.15 (c–c’). NanoWorld Pointprobe® NCL AFM probes were used.
    Figure 2 from “New Insights in the Ion Beam Sputtering Deposition of ZnO-Fluoropolymer Nanocomposites” by Maria Chiara Sportelli et al.: Atomic force microscopy (AFM) micrographs of ZnO-CFx nanocomposites having an inorganic phase volume fraction of φ = 0.05 (a–a’), φ = 0.10 (b–b’), and φ = 0.15 (c–c’).

    *Maria Chiara Sportelli, Marco Valentini, Rosaria Anna Picca, Antonella Milella, Angelo Nacci, Antonio Valentini and Nicola Cioffi
    New Insights in the Ion Beam Sputtering Deposition of ZnO-Fluoropolymer Nanocomposites
    Applied Sciences 2018, 8(1), 77
    DOI: 10.3390/app8010077

    Please follow this external link for the full article: https://www.mdpi.com/2076-3417/8/1/77/htm

    Open Access: The article « New Insights in the Ion Beam Sputtering Deposition of ZnO-Fluoropolymer Nanocomposites » by Maria Chiara Sportelli et al. 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/.