Nanowires replace Newton’s famous glass prism

Scientists have designed an ultra-miniaturized device that could image single cells without the need for a microscope or make chemical fingerprint analysis possible from within a smartphone camera.

Sir Isaac Newton in 1666 discovered the spectrum of colors contained in sunlight. The word “spectrum” was coined by Newton to describe the phenomenon he observed. He just used a triangular prism and sowed a seed of the new field of science to study the interaction between light and matter, called spectroscopy.

In today’s date, spectrometers are vital components in the industry and almost all fields of scientific research. It can tell us about the processes within galactic nebulae, millions of light-years away, just by analyzing the characteristics of light.

Currently used spectrometers are bulky and complicated and challenging to shrink to sizes much smaller than a coin. Four hundred years after Newton, University of Cambridge researchers have overcome this challenge to produce a system up to a thousand times smaller than those previously reported.

Scientists have developed a device an ultra-miniaturized device from a single nanowire- 1000 times thinner than a human hair to image individual cells without the need for a microscope or make chemical fingerprint analysis possible from within a smartphone camera. The device is the smallest spectrometer ever designed.

The nanowire used in work varied in material composition, including its length. This made the nanowire responsive to different colors of light across the visible spectrum. Scientists then used techniques similar to those used for the manufacture of computer chips and created a series of light-responsive sections on this nanowire.

Since the gadget is so small, it can straightforwardly picture single cells without the requirement for a microscope. Furthermore, unlike other bioimaging methods, the data obtained by the nanowire spectrometer contains a detailed analysis of the chemical fingerprint of every pixel.

First author Zongyin Yang from the Cambridge Graphene Centre said, “We engineered a nanowire that allows us to get rid of the dispersive elements, like a prism, producing a far simpler, ultra-miniaturized system than conventional spectrometers can allow. The individual responses we get from the nanowire sections can then be directly fed into a computer algorithm to reconstruct the incident light spectrum.”

Co-first author Tom Albrow-Owen said, “When you take a photograph, the information stored in pixels is generally limited to just three components – red, green, and blue. With our device, every pixel contains data points from across the visible spectrum, so we can acquire detailed information far beyond the colors which our eyes can perceive. This can tell us, for instance, about chemical processes occurring in the frame of the image.”

Dr. Tawfique Hasan, who led the study said, “Our approach could allow unprecedented miniaturization of spectroscopic devices, to the extent that could see them incorporated directly into smartphones, bringing powerful analytical technologies from the lab to the palm of our hands.”

According to scientists, this nanowire spectrometer could pave the way towards an entirely new generation of ultra-compact spectrometers working from the ultraviolet to the infrared range.

Scientists detailed the study in the journal Science.

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