Molecules that respond to light and other stimuli will revolutionise medicine and materials. This is the view of Kim Kuntze who has studied photoresponsive molecules in his doctoral research.
– A comparison of a piece of plastic and living tissue tells quite clearly how far we are from utilising the entire potential of chemistry, Kuntze states.
He envisions the next-generation materials to be responsive, even adaptive to their environment. This is possible by incorporating small, nanometre-sized components into the materials: switches, motors, and eventually machines.
Photoswitches are molecules that change their shape when exposed to light of a certain colour. When integrated into larger molecular assemblies, this gives rise to soft robots that deform in response to light stimuli and pharmaceuticals whose activity can be switched on or off with light. The scope of promising applications keeps on growing.
Only one obstacle stands in the way of this future: photoswitches typically utilise ultraviolet light, harmful to living cells in particular. In order to reach their full potential, compounds that operate with benign visible light, preferably red or infrared light, are needed.
In his doctoral dissertation Kuntze studied three strategies to activate photoswitches with red light: 1) shifting the operation colour of a conventional photoswitch from ultraviolet to red through structural modifications, 2) utilising new structures that intrinsically absorb red light, and 3) indirect photoswitching through the use of photocatalysts. All strategies were shown to function for switches and molecular motors alike.
– Each strategy has its advantages and challenges in realising efficient, fast, and durable photoswitching. Therefore, a single optimal photoswitch model cannot succeed in different applications. Instead, the photoswitch should be specifically tailored for each application, Kuntze concludes.
Kim Kuntze completed his Finnish high school degree in Turku in 2013. In March 2019, he graduated as a Master of Science from Tampere University. Next autumn, he began his doctoral research in the Smart Photonic Materials group under the supervision of Professor Arri Priimägi. A part of Kuntze’s research was conducted in the Nobel laureate Ben L. Feringa’s research group in the University of Groningen, The Netherlands. Alongside his research, Kuntze has also developed the teaching of organic chemistry and promoted ornithological citizen science.
Public defence on Friday 1 September
The doctoral dissertation of MSc Kim Kuntze in the field of chemistry titled Strategies for Red-Light Photoswitching will be publicly examined at the Faculty of Engineering and Natural Sciences at Tampere University at 13 o’clock on Friday 1st of September 2023 at Hervanta campus, Konetalo, auditorium K1702 (Korkeakoulunkatu 6, Tampere). The Opponent will be Priv.doz. Zbigniew Pianowski from Karlsruhe Institute of Technology. The Custos will be Professor Arri Priimägi from the Faculty of Engineering and Natural Sciences.
Photo: Meri Öhman