New sensor able to detect toxins leaching from plastic

PALMERSTON NORTH, New Zealand, Dec. 10 (UPI) -- Are toxins from that plastic food wrapper leaching into your lunch? Are carcinogens from that plastic bottle ending up the water you're drinking?

Those answers may be more easily answered thanks to engineers at Massey University in New Zealand.

Scientists Asif Zia and Subhas Mukhopadhyay have designed an electrochemical sensing system capable to detecting the presence of di(2-ethylhexyl)phthalate, or DEHP, a synthetic compound used to enhance flexibility in plastic products.

DEHP is a human hormone disrupter; and because it doesn't attach itself covalently to the lattice structure of plastic molecules, it can be more easily leached.

The sensor boasts a molecular imprinted polymer, which acts like Velcro for DEHP molecules. When swirled through a liquid solution, the sensor can detect DEHP levels as low as two parts per billion.

After a 10-minute trip through a liquid, scientists used spectroscopy to see if the tiny sensor -- measuring 2.5 millimeters by 2.5 millimeters -- has grabbed any DEHP molecules.

"Previous technology required taking a sample to the lab, where they would first have to separate the molecule in question and then test it via flame ionization detection, mass spectroscopy and high performance liquid chromatography," Zia explained in a press release. "This could take up to a week. Using electrochemical impedance spectroscopy, the test procedures takes only a few minutes."

In 2011, beverages around the world that had been exported from Taiwan had to be recalled after reports of illegal DEHP use as a clouding agent surfaced. Many of the beverage shipments sat in limbo for weeks as testing took place.

DEHP has been outlawed in the United States, but many countries around the world continue to use the compound.

"Plastic is a way of life, it's hard to get around that," said Zia. "Every day we could be ingesting tiny amounts of these compounds which, over time, can build up in the body and cause problems."

"This device provides a simple and cost-effective way to make sure there aren't harmful levels of contamination in juices or other drinks," Zia added.

Zia and Mukhopadhyay detailed their new sensor in the Biosensor and Bioelectronics Journal.

The researchers are now working on a biomedical version of their sensor, which will be able to detect collagen in blood samples.