Dissertation: Photoresponsive graphene surface is the future material (Korhonen)
Conditions affect the photocleaving properties
The photocleavable protective group used in the study was boron dipyrromethene (BODIPY), which protects amines, and the groups binding to graphene were aromatic anchor groups of different sizes. The research revealed that the size of the anchor group did not affect whether photocleavage took place, but the presence of oxygen in the solution influenced the rate of the photocleavage reaction and the decomposition products formed. When dissolved oxygen was removed from the solution, photocleavage was significantly faster, and the decomposition of the photoprotective group could be controlled better.
Removing the photoprotective group enables the selective modification of graphene
The developed BODIPY derivatives were utilized to modify the graphene surface. First, graphene was coated with the BODIPY compounds, after which the surface was patterned with a green laser. As a result, areas formed on the surface where photocleavage had occurred, and amine groups were released. The shape and size of the patterns, as well as the degree of photocleavage, could be controlled by changing the anchor group or the measurement parameters, such as irradiation time or laser spot size.
“Light-modifiable surfaces will enable the development of more advanced materials in the future. This method could potentially be utilized in applications that require precisely defined, chemically distinct areas on material surfaces. An example of such an application could be guidance of the nerve cell growth in a desired direction,” Korhonen explains.
The examination of the doctoral thesis of MSc Elsa Korhonen “Photocleavable boron dipyrromethene derivatives for selective functionalization of graphene surface” will be held on the 12th of December 2025 at 12:00 noon in the lecture hall KEM4 of the Department of Chemistry. The opponent is Professor Mauri Kostiainen (Aalto University) and the custos is Professor Maija Nissinen (University of Jyväskylä). The language of the defence is English.
The dissertation has been published as part of the JYU Dissertations series of the University of Jyväskylä and is available at https://urn.fi/URN:ISBN:978-952-86-1161-5
Information:
Elsa Korhonen
Department of Chemistry, University of Jyväskylä
