New way of optical visualization of nano objects proposed

March 29, 2019

High-resolution optical microscopy methods promise breakthroughs in materials science, biology, and medicine. Today, their possibilities basically reach those of scanning electron microscopy.

Sergey Kharintsev, Head of Nano-Optics Laboratory (Kazan Federal University), comments, "The main advantage of optical microscopy is that it provides nondestructive chemical analysis of single molecules exposed to continuous-wave low-powered laser light. Unlike scanning electron microscopy, this allows one to perform 3D visualization and spectral analysis of intrinsic structure of nano objects, and also get insights into processes in living cells."

According to Professor Kharintsev, fluorescence microscopy has become the most popular method for biology and medicine lately. Its main drawback is the need for fluorescent labels that must be photostable and non-toxic. Furthermore, there are factors of labor-intensive sample preparation and fluorophore prices.

The paper posits that one of the solutions for ultrahigh resolution microscopy is a superlens, first proposed by John Pendry (Imperial College London, UK) in 2000. The lens looks like a sandwich with a metallic film placed between two dielectric layers. Superresolution is achieved due to the optical near-field enhancement through surface plasmon resonances. Lately, a breakthrough initiative in practical implementation of such superlens has been put forth by Vladimir Shalaev (Purdue University, USA), who suggested using a nano-composite metal-dielectric film. This permits the superlens to be operated at a tunable single frequency.

"We propose to use a nano-structured metal-dielectric film that exhibits a double epsilon-near-zero behavior near the percolation threshold," continues Sergey Kharintsev. "The material in question is titanium oxynitride, a compound first synthesized by Andrei Mihai's group at Imperial College London. Such a superlens provides ultrahigh spatial resolution due to stimulated Raman scattering. Consequently, we have succeeded to achieve a spatial resolution of 8 nm and 80 nm in the near-field and far-field, respectively. Importantly, obtained optical images are formed with a standard objective only, not using optical nano-antennas, designed laser beams, or fluorescent labels."
The research has been supported by the Russian Science Foundation. The project's title is "Synthesis and research of ultra-thin magnetic heterostructures with potential spintronic and optronic applications"; Professor Lenar Tagirov (Institute of Physics, Kazan Federal University) is at the helm. Sergey Kharintsev's PhD student Anton Kharitonov has prepared his PhD thesis based on the results.

Kazan Federal University

Related Biology Articles from Brightsurf:

Experimental Biology press materials available now
Though the Experimental Biology (EB) 2020 meeting was canceled in response to the COVID-19 outbreak, EB research abstracts are being published in the April 2020 issue of The FASEB Journal.

Structural biology: Special delivery
Bulky globular proteins require specialized transport systems for insertion into membranes.

Cell biology: All in a flash!
Scientists of Ludwig-Maximilians-Universitaet (LMU) in Munich have developed a tool to eliminate essential proteins from cells with a flash of light.

A biology boost
Assistance during the first years of a biology major leads to higher retention of first-generation students.

Cell biology: Compartments and complexity
Ludwig-Maximilians-Universitaet (LMU) in Munich biologists have taken a closer look at the subcellular distribution of proteins and metabolic intermediates in a model plant.

Cell biology: The complexity of division by two
Ludwig-Maximilians-Universitaet (LMU) in Munich researchers have identified a novel protein that plays a crucial role in the formation of the mitotic spindle, which is essential for correct segregation of a full set of chromosomes to each daughter cell during cell division.

Cell biology: Dynamics of microtubules
Filamentous polymers called microtubules play vital roles in chromosome segregation and molecular transport.

The biology of color
Scientists are on a threshold of a new era of color science with regard to animals, according to a comprehensive review of the field by a multidisciplinary team of researchers led by professor Tim Caro at UC Davis.

Kinky biology
How and why proteins fold is a problem that has implications for protein design and therapeutics.

A new tool to decipher evolutionary biology
A new bioinformatics tool to compare genome data has been developed by teams from the Max F.

Read More: Biology News and Biology Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to