AUTHOR=Wang Pengfei , Liu Lijie , Meng Fanda , Khan Maroof Ahmad , Li Hui 

TITLE=“Turn-On” Fluorescent Biosensors for High Selective and Sensitive Detection of Al3+ Ion

JOURNAL=Frontiers in Chemistry

VOLUME=8

YEAR=2020

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2020.607614

DOI=10.3389/fchem.2020.607614

ISSN=2296-2646

ABSTRACT=<p>A series of new compounds (<bold>1</bold>-<bold>4</bold>) based on pyrrole hydrazone Schiff bases were designed and synthesized. The interactions of these new compounds with metal ions and their fluorescent recognition were investigated. All compounds showed “turn-on” fluorescence in the presence of Al<sup>3+</sup> in aqueous solution. Their sensing behaviors with Al<sup>3+</sup> were studied using photophysical experiments, ESI-MS spectrometry analysis, <sup>1</sup>H NMR titration, and DFT calculation. The detection limits of <bold>1</bold>-<bold>4</bold> for the analysis of Al<sup>3+</sup> were found to reach a 10<sup>−8</sup> M level in aqueous solution, which are far lower than the WHO guidelines for drinking water (7.41 mM for Al<sup>3+</sup>). A high selectivity test paper has been fabricated for Al<sup>3+</sup> detection based on sensor <bold>3</bold>. Theoretical calculations (DFT) have been carried out to elucidate the configuration of <bold>1</bold>-<bold>4</bold> and their Al complexes and rationalize experimental absorption data.</p>