'Visual Confirmation of Antibiotic Resistance'

Development of Bacterial (Pathogen) Detection Technology Using Dopamine Self-Polymerization Reaction
Simple Detection of Pathogen Growth
Expected Use for Real-Time Antibiotic Resistance Testing

Dopamine suppresses the luminescence of fluorescent nanoparticles through self-polymerization reactions, but in the presence of bacteria, the dopamine polymerization reaction is inhibited, restoring the fluorescence signal of the nanoparticles (partially used in the cover image).

[Asia Economy Reporter Junho Hwang] A technology has been developed that uses the properties of dopamine, a neurotransmitter in our body, to optically measure bacterial (pathogen) growth and antibiotic resistance, allowing visual confirmation.

The Korea Advanced Institute of Science and Technology (KAIST) announced on the 7th that a joint research team including Professor Hyunjeong Jeong from the Department of Life Sciences and Professor Haesin Lee from the Department of Chemistry developed this technology, and the related research paper was published in the international materials science journal Advanced Functional Materials.

Detecting Bacteria through Dopamine’s Oxygen Consumption

The research team devised a method to detect bacteria through dopamine’s self-polymerization reaction that consumes oxygen. They also manufactured fluorescent nanoparticles using dextran, a material that does not affect bacterial growth, and added them to the dopamine solution to enable visual confirmation. This method utilizes the fact that the result of dopamine polymerization varies depending on the oxygen consumption by bacteria within a certain solution.

Dopamine is used as a neurotransmitter in most living organisms and undergoes a self-polymerization reaction (where two or more molecules combine to form a large compound) in the presence of oxygen without the aid of other substances. The polymerized dopamine forms a dark brown color and adsorbs onto various material surfaces to form a layer.

Experimental results showed that in solutions with only dopamine and nanoparticles added, the solution turned dark brown due to dopamine oxidation and self-polymerization. Additionally, when fluorescent nanoparticles were added, the fluorescence was lost. This is because the self-polymerized dopamine adsorbs onto the surface of fluorescent nanoparticles in the solution, forming a layer that causes significant chemical and physical changes to the particles, weakening the previously strong fluorescent signal.

On the other hand, in solutions containing bacteria, oxygen was consumed due to bacterial growth, and the fluorescence signal of the nanoparticles maintained its original color. Also, the dopamine self-polymerization reaction was inhibited by bacterial growth, keeping the solution clear.

Experiment with Antibiotic-Resistant E. coli

The research team also applied this phenomenon to detect antibiotic resistance. They conducted experiments on Escherichia coli (E. coli) expressing 'New Delhi Metallo-beta-lactamase 1 (NDM-1)', which confers antibiotic resistance. As a result, the antibiotic-resistant bacteria continued to consume oxygen and grow in the experimental solution, making dopamine polymerization difficult within the solution.

Professor Hyunjeong Jeong said, "This study is significant as it elucidates dopamine’s self-polymerization reaction in a biological system and can be applied to real-time detection of bacterial growth and antibiotic resistance. It enables faster diagnosis than conventional microbial culturing methods and is simpler than PCR testing, which is expected to greatly contribute to preventing the spread of infectious diseases."

This content was produced with the assistance of AI translation services.