Development of a fluorescent method for determining esterase activity with terbium/BAPTA-AM system

Masahiko Saito, Hitoshi Hoshino

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Enzyme-amplified lanthanide luminescence (EALL) is a promising method which has been developed for enzymatically amplified signal detection. A signal is generated by enzymatically transforming a substrate into a product, which forms a fluorescent lanthanide chelate. With the aim of establishing a new EALL detection system, we focused on O, O'-bis(2-aminophenyl) ethyleneglycol-N, N, N ', N '-tetraacetic acid (BAPTA), which is known to be a specific chelator for calcium. BAPTA also forms some energy-transfer fluorescent complexes with lanthanide ions at physiological pH, and functions as a good sensitizer, especially for terbium(III) ion. Thus, we examined whether esterase activity can be determined by EALL detection where BAPTA and its tetraacetoxymethyl ester (BAPTA-AM) are used as the Tb(III) chelate and the reaction substrate, respectively. Regarding the rate of the Tb(III) fluorescent intensity changing per unit time (ΔI/Δt) as an initial rate of the enzymatic reaction, the determination of esterase activity was successfulin the range of 0.010 ~ 0.10 u/mL. Within this work, the suitability of the Tb(III)/ BAPTA-AM system for EALL detection has been proven for determining esterase activity.

Original languageEnglish
Pages (from-to)853-857
Number of pages5
Issue number10
Publication statusPublished - 2009


  • Esterase activity
  • Fluorescence
  • Terbium

ASJC Scopus subject areas

  • Analytical Chemistry


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