An international team of researchers from KAUST has developed a carbon-based semiconducting material with the potential to build next-generation biosensors. The team has overcome some key challenges in developing this polymer.
Several critical challenges were overcome to develop the new type of polymer that has great potential for next-generation biosensors. Image Credit: © 2021 KAUST; Xavier Pita.
Most of the present-day attempts involve novel types of biosensors that interact directly with the body to detect important biochemicals and act as indicators of health and disease.
For a sensor to be compatible with the body, we need to use soft organic materials with mechanical properties that match those of biological tissues.
Rawad Hallani, Former Research Scientist, KAUST
Hallani has developed the polymer in collaboration with various universities in the United States and the United Kingdom.
According to Hallani, the polymer has been developed for use in devices called organic electrochemical transistors (OECTs). For use in such devices, the polymer must permit specific ions and biochemical compounds to permeate into it and dope it, which will subsequently modulate its electrochemical semiconducting properties.
“The fluctuation in the electrochemical properties is what we are actually measuring as an output signal of the OECT,” Hallani added.
The research had to overcome several chemical challenges as even slight changes in the structure of the polymer can impact its performance. While several teams have attempted to develop this specific polymer, the KAUST team is the first to have emerged successfully.
The development is based on polymers called polythiophenes, which include the chemical groups known as glycols attached in accurately controlled positions. A crucial aspect of the innovation was to find new ways to control the locations of the glycol groups like never before.
Identifying the right polymer design to fit all the criteria that you are looking for is the tough part. Sometimes what can optimize the performance of the material can negatively affect its stability, so we need to keep in mind the energetic as well as the electronic properties of the polymer.
Rawad Hallani, Former Research Scientist, KAUST
The researchers used advanced computational chemistry modeling to realize the desired design. They also employed specialized x-ray scattering analysis and scanning tunneling electron microscopy to observe the polymer structure. These techniques showed how the location of glycol groups impacted the microstructure and electronic properties of the material.
We are excited by the progress Rawad made on the polymer synthesis, and we are now looking forward to testing our new polymer in specific biosensor devices.
Iain McCulloch, KAUST
Iain McCulloch is also associated with the University of Oxford in the United Kingdom.
According to McCulloch, the research group has been attempting to optimize the stability of their polymers and the sensors developed using them, as they transform from laboratory demonstrations to real-time applications.
Journal Reference:
Hallani, R.K., et al. (2021) Regiochemistry-Driven Organic Electrochemical Transistor Performance Enhancement in Ethylene Glycol-Functionalized Polythiophenes. Journal of the American Chemical Society. doi.org/10.1021/jacs.1c03516.