Gorgeous rainbow-colored, stretchy film for distinguishing sugars

Gorgeous rainbow-colored, stretchy film for distinguishing sugars (video)
A rainbow-colored, kaleidoscope-like film can tell sugars apart, distinguishing between different sweet beverages and sweat samples. Credit: American Chemical Society

Rainbows and sugar may conjure up images of a certain leprechaun-branded breakfast cereal. But now, researchers in ACS Nano report a kaleidoscope-like film for telling different sweeteners apart that displayed multiple colors when stretched by hand. When evenly stretched with a simple apparatus, the material enhanced the unique shifts in fluorescence intensity of 14 sugars tagged with a dye, distinguishing between them in beverages and sweat samples.

Sweet tastes in drinks can come from many types of sugar, including sucrose, fructose and glucose, as well as less common ones, such as maltose. There are also sugars in people's sweat, which could be tracked to noninvasively monitor . It's hard to tell which molecules are present based on taste or look alone; instead, they're usually identified with complex methods and sophisticated instruments. To simplify the detection process, Fengyu Li and colleagues previously used —polystyrene nanospheres whose color shifts when sugary compounds are nearby—in a color-changing chip sensor that distinguished 12 different sugars from one another. But these sensors weren't wearable, so, Li, Chunbao Li and a new team wanted to incorporate photonic crystals into a stretchable easy-to-carry film and see whether the rainbow-colored platform could also detect and differentiate sugars.

The researchers embedded closely packed, ordered rows of polystyrene nanospheres into a film of polyethyl acrylate. Initially, the gummy material looked red, but when it was stretched with a uniform force, its color shifted through the rainbow—red to pink to orange to yellow-green to light green and, finally, dark green at a 40% stretch. And when pulled by hand, the material produced a kaleidoscope of , as different parts of the material had different forces on them.

In initial experiments, the researchers showed that stretching the film enhanced the fluorescent signals from 14 sugars that had been attached to dyes. These signals could then be sorted from one another. To see if the sensor could do the same with real-world samples, they mixed six commercially available drinks with the dye alizarin red S-2-diphenylboronic acid 2-aminoethyl ester, creating fluorescent complexes. Solutions with these complexes were dotted onto the film, which was then stretched, and the fluorescence intensities were measured at two different wavelengths of light. And because each samples' sugar-dye complexes produced unique signals, they could be distinguished from each other. The sensor also differentiated sweat samples from six people. Based on these results, the researchers say that the stretchable, multicolored material could be incorporated into wearable devices for environmental, clinical or health monitoring of , or modified to detect other substances.

More information: Xinyuan Xie et al, A Rainbow Structural Color by Stretchable Photonic Crystal for Saccharide Identification, ACS Nano (2022). DOI: 10.1021/acsnano.2c08708

Journal information: ACS Nano

Citation: Gorgeous rainbow-colored, stretchy film for distinguishing sugars (2022, November 30) retrieved 27 January 2023 from https://phys.org/news/2022-11-gorgeous-rainbow-colored-stretchy-distinguishing-sugars.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Explore further

Colorfully detecting stressed-out polymer films, gels before they break

63 shares

Feedback to editors