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 (Al3+). It exhibits a highly sensitive "turn-on" fluorescent response toward Al3+ with a 70-fold fluorescence intensity enhancement under 2 equiv. of Al3+ added. The probe can be applied to the quantification of Al3+ with a linear range covering from 5.0 x 10(-7) to 2.0 x 10(-5) M and a detection limit of 4.0 x 10(-8) M. Most importantly, the fluorescence changes of the probe are remarkably specific for Al3+ 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 Al3+ 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 Al3+ in water samples and image Al3+ in living cells with satisfying results. (C) 2015 Elsevier B.V. All rights reserved.