KAIST Develops Catalyst and Platform for On-Site Disease Diagnosis in Three Minutes

A high-sensitivity sensor platform capable of visually diagnosing diseases within three minutes has been developed in South Korea. This was made possible by implementing a 'nanozyme', an enzyme-mimicking catalyst, with a selectivity more than 38 times higher than existing technologies.

KAIST announced on July 28 that a research team led by Professor Jinwoo Lee from the Department of Biological Sciences and Chemical Engineering, in collaboration with Professor Jungwoo Han from Seoul National University and Professor Moonil Kim from Gachon University, has developed a new single-atom catalyst that selectively performs only peroxidase reactions while maintaining high reaction efficiency, as well as a high-sensitivity sensor platform utilizing this catalyst.

(Top left) Professor Jinwoo Lee, (left) PhD candidate Sunhye Park, (right) PhD candidate Daeun Choi. Provided by KAIST

The core of on-site diagnostic technology is to use enzymes to observe color changes in biomarkers and visually confirm the presence or absence of disease. However, when using natural enzymes, the high cost and instability depending on the diagnostic environment make storage and distribution difficult.

To address these issues, enzyme-mimicking catalysts using new inorganic materials have been developed. However, low reaction selectivity has remained a limitation.

For example, when hydrogen peroxide is used as a substrate, a single catalyst can simultaneously induce both peroxidase (which causes color change) and catalase (which removes the reaction substrate) reactions, leading to decreased diagnostic signal accuracy.

To control the reaction selectivity of the catalyst at the atomic level, the joint research team designed the catalyst by binding a 'chlorine (Cl) ligand' in a three-dimensional orientation to the central metal, ruthenium (Ru). As a result, they succeeded in detecting only accurate diagnostic signals. In this process, the chlorine ligand plays a role in adjusting the chemical properties by binding to the metal.

The catalyst developed by the joint research team demonstrated significantly improved performance compared to previous enzyme-mimicking catalysts. Experiments also confirmed a marked increase in both reaction sensitivity and speed according to hydrogen peroxide concentration.

In particular, the catalyst maintained stable reaction selectivity and activity even in environments close to those of biological fluids (pH 6.0), proving its applicability in real diagnostic settings.

Schematic diagram of selective oxidation enzyme reaction and biomarker detection. Provided by KAIST

The joint research team also developed a diagnostic platform using the catalyst, capable of simultaneously detecting four types of biomarkers: glucose, lactate, cholesterol, and choline.

This platform can be universally applied to various disease diagnoses, allowing visual determination of disease presence within three minutes through color change, without the need for separate pH adjustment or complex equipment. This demonstrates that diagnostic performance can be dramatically improved solely by controlling the catalyst structure, without modifying the platform itself.

Professor Jinwoo Lee stated, "This study is significant in that it simultaneously achieved enzyme-level selectivity and reactivity by controlling the reaction selectivity of a single-atom catalyst through atomic structure design. The catalyst design strategy based on structure-function relationships can be applied to the development of various metal-based catalysts in the future, and may be extended to a wide range of reaction fields where selectivity control is crucial."

This research was supported by the Ministry of Science and ICT and the National Research Foundation of Korea. Sunhye Park and Daeun Choi, doctoral students in the Department of Biological Sciences and Chemical Engineering at KAIST, participated as co-first authors. The research results were published on July 6 in the international journal Advanced Materials in the field of materials science.

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