A team of researchers from New Zealand have created a new sensor that can detect low levels of estrogen, the primary female hormone, in liquids.
The sensor made by the team from Victoria University in Wellington can detect E2, which is among the primary estrogen hormones. The unit sends electronic signals once it finds estrogen and can soon test levels of the hormone in saliva or contamination in waterways, which could be a potential threat for the environment.
Despite being a tiny molecule, estrogen can massively affect humans and animals. Regulating female reproductive status, it can be used for tracking fertility or for control the reproductive cycle and health of livestock.
The sensor, introduced in a paper published in the Journal of Vacuum Science and Technology B, delivers real-time readings and can be integrated into a system for electronic monitoring. It is also energy-efficient, making it advantageous over most other detection tools.
Aptamers or small DNA snippets are used by the device to make estrogen molecules stick.
"[They] are a potentially powerful tool for sensors because they are so versatile and selective," said Victoria University researcher Natalie Plank, who studies nanomaterial device fabrication.
The small snippets of DNA are developed using a process akin to natural selection. Working with a diverse range of DNA and RNA nucleotide sequences, the scientists then selectively enriched those that bound best to the target molecule, repeating the procedure over numerous generations.
The researchers attached the estrogen-binding aptamers to the carbon nanotube thin film field effect transistor, which works like conventional transistors but utilize carbon nanotubes rather than silicon. They also plan to conduct trials of the device in more complex settings, such as with urine, a real biological fluid.
In the future, too, the sensor may no longer be just about estrogen detection, with the aptamers readily replaceable with new ones targeting a different molecule. "It's a very versatile way to build a sensor," Plank noted.
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