Portable AIE Handy Pen designed for on-the-spot toxic gas detection
Although there already are devices that can detect harmful gases, most of them aren't particularly portable, nor are they simple to use. An experimental new tool, however, is about the size of a hypodermic needle – and it could be utilized by anyone, anywhere.
Developed by a team of scientists from Dongguan University of Technology, Shenzhen Institute of Advanced Technology (CAS), Hong Kong University of Science and Technology (HKUST), AIE Institute and other Chinese universities, the device is called the AIE Handy Pen. It incorporates fluorescing compounds known as aggregation-induced emission fluorogens (AIEgens), which have previously been used in more complicated gas-detection systems.
In the AIE Handy Pen, a needle-like tip made up of silicon dioxide polymer fibers is initially coated with AIEgens that fluoresce in a specific color, in the presence of a specific gas. When the pen isn't in use, that spring-loaded tip is retracted inside the main body of the device. Once it's time to test for the targeted gas, though, a plunger on the back of the pen is used to briefly slide the tip out into the air.
Once the tip has had a chance to be exposed to the gas in question, it's pulled back inside the pen. It's then illuminated by an internal LED. If the targeted gas is present, it will have been absorbed by the AIEgens, which will in turn respond to the light exposure by fluorescing in a given color. A viewing window in the side of the pen lets users see that color-change.
In tests conducted so far, one tip was successfully used to detect the presence of diethyl chlorophosphite (DCP) nerve gas by fluorescing yellow after exposure, instead of its default blue. Another tip – coated with different AIEgens – underwent a similar change in color after being exposed to volatile amine vapors, which are given off by spoiled food. In both cases, subsequent exposure to neutralizing vapors returned the tips to their original state, making them reusable.
It is hoped that once the technology is developed further, AIE Handy Pens with a variety of gas-specific tips could be utilized in fields such as food safety, environmental monitoring or public safety.
A paper on the research was recently published in the journal ACS Materials Letters.
Source: American Chemical Society