ETH Zurich researchers have created new fluorescent dyes that are simple and inexpensive to make. The dyes are made up of modular polymers with varying numbers of subunits that determine their color. The subunits are either easily obtainable commercially or can be produced in a single reaction step by chemists.
Yinyin Bao, a senior scientist in the groups of ETH professors Jean-Christophe Leroux and Chih-Jen Shih, led a team of scientists in successfully using a new approach to generate a diverse spectrum of colors, including red, which was previously challenging to produce. Working with scientists from RMIT University in Melbourne, they utilized artificial intelligence algorithms to determine the required number of molecule subunits for each desired color.
Potential applications for the fluorescent inks include UV-activated security inks for banknotes, certificates, passports, or for encrypting information. The method can also be used to produce inks that change color after prolonged UV illumination. In their new work, which the scientists published in the scientific journal Chem, they demonstrated this using the example of two initially red fluorescent inks, one of which turns blue after several minutes of UV illumination, while the other remains red. This property can also be used for security features.
Other applications for the new fluorescent molecules are in solar power plants, or they could one day be combined with semiconducting molecules to produce low-cost organic light-emitting diodes (OLEDs) for displays.
Reference: “Machine learning-assisted exploration of a versatile polymer platform with charge transfer-dependent full-color emission” by Suiying Ye 1, Nastaran Meftahi, Igor Lyskov, Tian Tian, Richard Whitfield, Sudhir Kumar, Andrew J. Christofferson, David A. Winkler, Chih-Jen Shih, Salvy Russo, Jean-Christophe Leroux and Yinyin Bao, 2 January 2023, Chem.