A highly sensitive and selective fluorescent probe for trivalent aluminum ion based on rhodamine derivative in living cells.

A rhodamine spirolactam derivative ( 1 ) is developed as a colormetric and fluorescent probe for trivalent aluminum ions (Al 3+ ). It exhibits a highly sensitive “turn-on” fluorescent response toward Al 3+ with a 70-fold fluorescence intensity enhancement under 2 equiv. of Al 3+ added. The probe can be applied to the quantification of Al 3+ with a linear range covering from 5.0 × 10 −7 to 2.0 × 10 −5 M and a detection limit of 4.0 × 10 −8 M. Most importantly, the fluorescence changes of the probe are remarkably specific for Al 3+ in the presence of other metal ions, which meet the selective requirements for practical application. Moreover, the experiment results show that the response behavior of 1 towards Al 3+ is pH independent in neutral condition (pH 6.0–8.0) and the response of the probe is fast (response time less than 3 min). In addition, the proposed probe has been used to detect Al 3+ in water samples and image Al 3+ in living cells with satisfying results. [ABSTRACT FROM AUTHOR]