New rhodamine B boronic acid derivatives and fluorescein boronic acid derivative for chemosensors for catecholamines and Cu2+ ion

ORGN 195

Sook Kyung Kim, Ha Na Lee, KMK. Swamy, and Juyoung Yoon, jyoon@ewha.ac.kr. Division of Nano Sciences and Department of Chemistry, Ewha Womans University, 11-1, Daehyun-dong, Seodaemun-gu, Seoul, 120750, South Korea
Sensors based on fluorescent changes appear to be particularly attractive due to the simplicity and high detection limit of the fluorescence. Catecholamines, including dopamine, are involved in a number of biological processes, such as Parkinson's disease and hypertension. A Rhodamine B derivative bearing boronic acid moiety has been prepared and used as fluorescent chemosensor. In order to detect biologically important copper ion in cells and organisms, monobroronic acid-conjugated rhodamine and bisboronic acid-conjugated fluorescein probes were designed and synthesized. The monoboronic acid-conjugated rhodamine probe displays a highly selective fluorescent enhancement with Cu2+, among the various metal ions. In contrast, the fluorescence of the bisboronic acid-conjugated fluorescein probe is selectively quenched by Cu2+, probably by way of a PET mechanism. The practical use of the monoboronic acid-conjugated rhodamine probe was demonstrated by its application to the detection of copper ions in mammalian cells and organisms.