A colorimetric and turn-on fluorescent chemosensor for Al(III) based on a chromone Schiff-base.

A simple Schiff-base receptor 7-methoxychromone-3-carbaldehyde-(pyridylformyl) hydrazone (MCNH) was prepared. It exhibits an "off-on-type" mode with high sensitivity in the presence of Al(3+). This compound could be used as Al(3+) probe in ethanol and it features visible light excitation (433 nm) and emission (503 nm) profiles.