Real-time dopamine measurement using a flexible probe that minimizes brain damage

A research team led by Jang Kyung-in, an affiliate professor in the Department of Robotics and Mechatronics Engineering at DGIST, has developed a dopamine measuring device capable of accurately analyzing dopamine concentration in real time while minimizing the brain damage.

Because the device facilitates precise, real-time dopamine measurements using a single flexible probe implantable in the brain, it is expected to be used as a core technology for developing personalized probes for patients with degenerative brain diseases. The results are published in the journal Advanced functional materials.

Dopamine is an essential neurotransmitter widely distributed in the central nervous system and associated with brain functions such as motivation, memory, and reward. When the concentration of dopamine in the brain is abnormally high or low, it can cause degenerative brain diseases. For this reason, it is important to measure dopamine concentrations in the brains of patients suffering from these diseases.

Existing implantable brain probes have a rigid structure that is unsuitable for the soft tissues of the brain, and at least two probes are needed for dopamine measurement. Because of these issues, existing brain implantable probes can cause damage or inflammation to brain tissue, disrupting the ability to consistently and accurately measure dopamine levels.

Researchers have proposed technologies to develop brain implantable probes based on flexible devices; however, these technologies still require either large probes or the insertion of multiple probes, which can result in significant brain damage.

To overcome the limitations of existing probes, Professor Jang’s research team developed technology that facilitates dopamine measurement by safely and stably inserting a single flexible probe over the long term. The proposed probe has a double-sided structure, with working and reference electrodes installed on one side and a counter electrode installed on the other side. Based on this structure, the proposed probe offers a measurable surface area approximately twice that of existing probes (based on a single surface structure) while maintaining the same insertion area.

Furthermore, the specific surface area of ​​the proposed probe was significantly expanded through the implementation of a complex structure of three-dimensional zinc oxide (ZnO)-based nanorods in the working electrode. Therefore, the proposed technology is considered a novel probe-based dopamine sensor that minimizes damage to brain tissue and maximizes the functions of the probe.

When electrodes are located on both sides of a probe, the distance between the neutral layer of the probe and the electrodes increases. This structural limitation leads to a mechanically unstable state of the electrodes at the time of probe modification. To solve this problem, Professor Jang’s research team designed a serpentine-patterned microelectrode that could contribute to the mechanical stability of the electrodes, despite their modification.

Professor Jang says: “The developed probe based on the double-sided structure facilitates very accurate and stable measurement of dopamine concentration in the long term, which has not been achieved with the use of existing probes. It has the potential to serve as a standard for probes. development to support patients with brain diseases.

He added: “The precision and stability of the developed probe were verified by experiments on mice. We will conduct further research to introduce more improved brain implantable probe technology that can increase the satisfaction of patients with brain diseases throughout their lives. »

Provided by Daegu Gyeongbuk Institute of Science and Technology (DGIST)