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Aggregation-Induced Emission Probe for Light-Up and in Situ Detection of Calcium Ions at High Concentration
journal contribution
posted on 2018-04-19, 13:50 authored by Meng Gao, Yunxia Li, Xiaohui Chen, Shiwu Li, Li Ren, Ben Zhong TangThe fluorescent probe for the detection
of calcium ions is an indispensable tool in the biomedical field.
The millimolar order of Ca(II) ions is associated with many physiological
processes and diseases, such as hypercalcemia, soft tissue calcification,
and bone microcracks. However, the conventional fluorescent probes
are only suitable for imaging Ca(II) ions in the nanomolar to micromolar
range, which can be because of their high affinities toward Ca(II)
ions and aggregation-caused quenching drawbacks. To tackle this challenge,
we herein develop an aggregation-induced emission (AIE) probe SA-4CO2Na for selective and light-up detection of Ca(II) ions in
the millimolar range (0.6–3.0 mM), which can efficiently distinguish
between hypercalcemic (1.4–3.0 mM) and normal (1.0–1.4
mM) Ca2+ ion levels. The formation of fibrillar aggregates
between SA-4CO2Na and Ca(II) ions was clearly verified
by fluorescence, scanning electron microscopy, and transmission electron
analysis. Moreover, this AIE-active probe can be used for wash-free
and light-up imaging of a high concentration of Ca(II) ions even in
the solid analytes, including calcium deposits in psammomatous meningioma
slice, microcracks on bovine bone surface, and microdefects on hydroxyapatite-based
scaffold. It is thus expected that this AIE-active probe would have
broad biomedical applications through light-up imaging and sensing
of Ca(II) ions at the millimolar level.