Chemical Communications Blog

A simple red-to-purple colour change test could detect food or drinks contaminated with phthalates, say Chinese scientists.

Phthalates are used as plasticisers in some types of plastic food packaging; however, due to their toxicity, there are strict rules to prevent them leaching into food or drinks, or being used directly as food additives. In spite of this, there have been several recent scandals where phthalates have entered the food chain.

The analytical test proposed by Bang-Ce Ye and his team from East China University of Science and Technology, Shanghai, uses gold nanoparticles modified with uridine 5′-triphosphate to detect the phthalates. In the presence of phthalates and Cu2+, the modified gold nanoparticles are cross-linked together with the phthalates, forming a bridge between different nanoparticles. The cross-linking reaction causes aggregation of the nanoparticles and the distinctive red-to-purple colour change.

The test can tell whether food or drink has been contaminated with toxic phthalates to levels of 0.5ppm, below the set safety limit of 1.5ppm

Read the full Chemistry World news story here

Link to journal Article
Rapid and sensitive colorimetric visualization of phthalates using UTP-modified gold nanoparticles cross-linked by copper(II)
Min Zhang, Yu-Qiang Liu and Bang-Ce Ye
Chem. Commun., 2011, DOI: 10.1039/c1cc14772b