National Engineering Research Center for Tissue Restoration and Reconstruction , South China University of Technology , Guangzhou 510006 , China.
Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction , The Hong Kong University of Science & Technology , Clear Water Bay, Kowloon , Hong Kong, China.
ACS Appl Mater Interfaces. 2018 May 2;10(17):14410-14417. doi: 10.1021/acsami.8b00952. Epub 2018 Apr 19.
The 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-4CONa 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) Ca ion levels. The formation of fibrillar aggregates between SA-4CONa 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.
用于检测钙离子的荧光探针是生物医学领域中不可或缺的工具。毫摩尔级别的 Ca(II)离子与许多生理过程和疾病有关，如高钙血症、软组织钙化和骨微裂缝。然而，传统的荧光探针仅适用于成像纳米摩尔到微摩尔范围内的 Ca(II)离子，这可能是由于它们对 Ca(II)离子的高亲和力和聚集引起的猝灭缺陷。为了应对这一挑战，我们在此开发了一种聚集诱导发射（AIE）探针 SA-4CONa，用于在毫摩尔范围内（0.6-3.0 mM）选择性和点亮检测 Ca(II)离子，能够有效地区分高钙血症（1.4-3.0 mM）和正常（1.0-1.4 mM）Ca 离子水平。通过荧光、扫描电子显微镜和透射电子分析清楚地证实了 SA-4CONa 与 Ca(II)离子之间形成纤维状聚集。此外，这种 AIE 活性探针即使在固体分析物中（包括沙粒状脑膜瘤切片中的钙沉积物、牛骨表面的微裂缝和基于羟基磷灰石的支架上的微缺陷）也可以用于高浓度 Ca(II)离子的无冲洗和点亮成像。因此，预计这种 AIE 活性探针将通过在毫摩尔水平上对 Ca(II)离子进行点亮成像和传感而具有广泛的生物医学应用。
