Tag Archives: Catalan Institute of Nanoscience and Nanotechnology

Nondirect relationships between the number of hydrogen bonds in DNA pairs and their relative strengths (three can be less than two)

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Michael Berger’s Oct. 10, 2017 Nanowerk Spotlight article features research from the Institut Català de Nanociència i Nanotecnologia, (Catalan Institute of Nanoscience and Nanotechnology and acronym ICN2) which has nothing to do with recent vote on independence (for more, see this Oct. 23, 2017 article about how countries such as ‘Catalonia’ and others do and don’t gain independence in The Atlantic),

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This is the first report on the electrical characterization of DNA with intrabond resolution.

Specifically, it quantifies electrical forces due to a single hydrogen bond in DNA and provides proof of a non-direct relationship between the number of hydrogen bonds in DNA pairs and the relative strengths of such pairs.

Such understanding of the relative strengths of the forces involved in the specific bonding of DNA as well as its electrical origin provides physical foundations to control mechanisms associated with DNA stability. It could help to develop new methods for the understanding, characterization; and control of relevant events originated at intrabond scales e.g. controlled DNA repair and damage; controlled modification of the expression of the genome; and communications below the single bond limit.

A blackboard representation of the manuscript’s key message: the quantification of the relative strengths between base pairs in DNA due to zipping hydrogen bonds might place on doubt such mechanisms regarding the interpretation of thermodynamic properties of DNA based on the assumption that A/T pairs are weaker than G/C pairs due to the sole difference in the number of hydrogen bonds, 2 and 3 respectively. (Image: Dr. Yamila García-Martínez)

Generally, being able to control DNA stability at the single bond level by means of electromagnetic interactions opens new avenues to induce modifications of the replication and transcription processes of DNA by means of noncontact methods.

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Going forward, the researchers will study the effects of external electromagnetic fields on DNA at the level of single bond events. This will have not only an enormous interest in the medical field but also in nanotechnology where it would open the door to non-contact atomic manipulation of DNA – the analogue to the CRISPR gene editing method [emphasis mine] but using electromagnetic fields to drive changes in DNA.

Interesting stuff, eh?

Here’s a link to and a citation for the paper,

Unveiled electric profiles within hydrogen bonds suggest DNA base pairs with similar bond strengths by Y. B. Ruiz-Blanco, Y. Almeida, C. M. Sotomayor-Torres, Y. García. PLOS [Public Library of Science] https://doi.org/10.1371/journal.pone.0185638 Published: October 5, 2017

This paper is open access.

Nanocellulose as a biosensor

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While nanocellulose always makes my antennae quiver (for anyone unfamiliar with the phrase, it means something along the lines of ‘attracts my attention’), it’s the collaboration which intrigues me most about this research. From a July 23, 2015 news item on Azonano (Note: A link has been removed),

An international team led by the ICREA Prof Arben Merkoçi has just developed new sensing platforms based on bacterial cellulose nanopaper. These novel platforms are simple, low cost and easy to produce and present outstanding properties that make them ideal for optical (bio)sensing applications. …

ICN2 [Catalan Institute of Nanoscience and Nanotechnology; Spain] researchers are going a step further in the development of simple, low cost and easy to produce biosensors. In an article published in ACS Nano they recently reported various innovative nanopaper-based optical sensing platforms. To achieve this endeavour the corresponding author ICREA Prof Arben Merkoçi, Group Leader at ICN2 and the first author, Dr Eden Morales-Narváez (from ICN2) and Hamed Golmohammadi (visiting researcher at ICN2), established an international collaboration with the Shahid Chamran University (Iran), the Gorgan University of Agricultural Sciences and Natural Resources (Iran) and the Academy of Sciences of the Czech Republic. [emphases mine]

Spain, Iran, and the Czech Republic. That’s an interesting combination of countries.

A July 23, 2015 ICN2 press release, which originated the news item, provides more explanations and detail,

Cellulose is simple, naturally abundant and low cost. However, cellulose fibres ranging at the nanoscale exhibit extraordinary properties such as flexibility, high crystallinity, biodegradability and optical transparency, among others. The nanomaterial can be extracted from plant cellulose pulp or synthetized by non-pathogenic bacteria. Currently, nanocellulose is under active research to develop a myriad of applications including filtration, wound dressing, pollution removal approaches or flexible and transparent electronics, whereas it has been scarcely explored for optical (bio)sensing applications.

The research team led by ICREA Prof Arben Merkoçi seeks to design, fabricate, and test simple, disposable and versatile sensing platforms based on this material. They designed different bacterial cellulose nanopaper based optical sensing platforms. In the article, the authors describe how the material can be tuned to exhibit plasmonic or photoluminescent properties that can be exploited for sensing applications. Specifically, they have prepared two types of plasmonic nanopaper and two types of photoluminescent nanopaper using different optically active nanomaterials.

The researchers took advantage of the optical transparency, porosity, hydrophilicity, and amenability to chemical modification of the material. The bacterial cellulose employed throughout this research was obtained using a bottom-up approach and it is shown that it can be easily turned into useful devices for sensing applications using wax printing or simple punch tools. The scientific team also demonstrates how these novel sensing platforms can be modulated to detect biologically relevant analytes such as cyanide and pathogens among others.

According to the authors, this class of platforms will prove valuable for displaying analytical information in diverse fields such as diagnostics, environmental monitoring and food safety. Moreover, since bacterial cellulose is flexible, lightweight, biocompatible and biodegradable, the proposed composites could be used as wearable optical sensors and could even be integrated into novel theranostic devices. In general, paper-based sensors are known to be simple, portable, disposable, low power-consuming and inexpensive devices that might be exploited in medicine, detection of explosives or hazardous compounds and environmental studies.

Here’s a link to and a citation for the paper,

Nanopaper as an Optical Sensing Platform by Eden Morales-Narváez, Hamed Golmohammadi, Tina Naghdi, Hossein Yousefi, Uliana Kostiv, Daniel Horák, Nahid Pourreza, and Arben Merkoçi.ACS Nano, Article ASAP DOI: 10.1021/acsnano.5b03097 Publication Date (Web): July 2, 2015
Copyright © 2015 American Chemical Society

This paper is behind a paywall.