A novel self-assembled nanoprobe for the detection of aluminum ions in real water samples and living cells

Aluminum ions, as a kind of non-essential element, show a negative impact on plants growth and contribute to diseases caused by nervous breakdown like Alzheimer's disease and Parkinson's disease. Hence, the detection of Al3+ in environment and human body is of great significance and valuableness. Herein, a N-H-type excited-state intramolecular proton transfer (ESIPT) based self-assemble nanoprobe has been designed and synthesized for the detection of Al3+. Owing to phthalandione and tosyl group, probe ABTTA could self-assemble into nanoparticles with nearly no fluorescence. However, ABTTA would be further aggregated by Al3+ ions in aqueous solution which results in enhanced fluorescence (peaking at 555 nm). Based on this principle, a novel analytical method for detection of Al3+ was established with a limit of detection of 50 nM, which was much better than most of reported probes. Moreover, the nanoprobe with excellent water solubility was successfully applied for the detection of Al3+ in real water sample with satisfactory measurement accuracy. Benefited from the favorable water solubility, the nanoprobe was further utilized to the detection of Al3+ in human cancer samples, demonstrating its potential application for biological imaging.