Professor Kyo Han Ahn (Department of Chemistry) and his team, in a joint research with a Yonsei University group, have developed a new probe for mercury that can be used for imaging organs in living organisms.

Mercury is a highly toxic and widespread pollutant, but the existing fluorescence probes for it mostly detected only its inorganic forms. The element is commonly found in organic forms which are much more toxic than inorganic mercury as their lipophilicity allows them to cross biological membranes. Consequently, new ways of detecting organic mercury species, particularly in organisms, was of crucial importance.

The research team has developed a structurally simple probe which reacts with both organic and inorganic mercury to give a fluorescent product. The probe was used to monitor methylmercury species in mammalian cells and zebrafish organs incubated with methylmercury.

While existing probes for inorganic mercury used heteroatomic ligands, Professor Ahn’s group took a different approach, making a conceptual advance: inspiration was taken from the field of oxymercuration reactions, in which alkenes, unsaturated hydrocarbons, when met with mercury, react to water.

Professor Ahn said the probe could be vital to the study of organic mercury poisoning in living species. “Now we have a molecular probe that can be used for studying and tracing the notoriously toxic methylmercury in living species. By using the probe, we may study the distribution and fate of methylmercury in organisms,” he explained.

Professor Ahn also added that the next step was to develop a probe that is more discriminating. “One of the most challenging issues in mercury sensing is to discriminate methylmercury from inorganic mercury,” said Professor Ahn. “We do not have such a molecular probe yet but we are working on it.”

The findings were published in the Royal Society of Chemistry’s Chemical Communications, and highlighted in Chemical Biology and other magazines.

Professor Kyo Han Ahn
Department of Chemistry
Tel: +82-54-279-2105
Fax: +82-54-279-3399
E-mail: ahn@postech.ac.kr