A simple Schiff base as ‘naked eye’ and fluorescent ‘on–off’ sensor for detecting cyanide in mixed aqueous solution

<p>A simple Schiff base sensor (L<sub>1</sub>) derived from N-(1-naphthyl) ethylenediamine dihydrochloride was designed and synthesised by simple chemistry procedures. The sensor exhibited a visible colour change observed by both colorimetric and fluorimetric responses for cyanide ion in aqueous solution. The detection of cyanide was performed via the nucleophilic attack of cyanide anion on the imine group of the sensor with a 1 : 1 binding stoichiometry. Moreover, test strips based on the sensor were fabricated, which served as convenient and efficient CN<sup>−</sup> test kits and the sensor L<sub>1</sub> is a good way to detect hydrogen cyanide in aqueous extracts of sprouting potatoes.</p>