March 2, 2011

Record Shattered For Highest-Resolution Microscope

British researchers have unveiled a high-resolution optical microscope that uses tiny glass beads to image objects just 50 nanometers in size.

The invention is the highest-resolution microscope ever demonstrated, and shatters the record for the smallest object the eye can see while providing a direct view into the "nanoscopic" world.

Until now, standard optical microscopes only displayed objects around one micrometer in size clearly.

By combining an optical microscope with a transparent microsphere dubbed the 'microsphere nanoscope', the researchers can see 20 times smaller, or 50 nanometers, under normal lights -- exceeding the theoretical limit of optical microscopy.

This vastly increased capacity means the scientists, led by Professor Lin Li and Dr Zengbo Wang of the University of Manchester, could potentially examine the inside of human cells, and view live viruses for the first time to see what causes them.

Although standard electron microscopes have the capacity to examine tiny items, they can only see the surface of a cell rather than its structure, meaning they could not provide a visual view a live virus.

The British researchers believe their new nano-imaging system will be able to detect far smaller images in the future.   Indeed, the new method has no theoretical limit in the size of feature that can be seen.

The system is based on capturing optical, near-field virtual images, which are free from optical diffraction.  These virtual images are then amplified using a microsphere, a tiny spherical particle that is further relayed and amplified by a standard optical microscope.

Professor Li, who initiated and led the research in collaboration with academics at the National University and Data Storage Institute of Singapore, believes the research could prove to be an important development.

"This is a world record in terms of how small an optical microscope can go by direct imaging under a light source covering the whole range of optical spectrum," he said.

"Not only have we been able to see items of 50 nanometers, we believe that is just the start and we will be able to see far smaller items.

"Theoretically, there is no limit on how small an object we will be able to see.

"The common way of seeing tiny items presently is with an electron microscope, and even then you cannot see inside a cell "“ only the outside. Optical fluoresce microscopes can see inside the cells indirectly by dying them, but these dyes cannot penetrate viruses.

"Seeing inside a cell directly without dying and seeing living viruses directly could revolutionize the way cells are studied and allow us to examine closely viruses and biomedicine for the first time."

Among other tiny objects the scientists will be able to examine are anodized aluminum oxide nano-structures, and nano-patterns on Blue-Ray CVC disks, not previously visible with standard optical microscopes.

The research was published in journal Nature Communications.


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