A highly sensitive and selective bis(salamo)-type fluorescent chemosensor for identification of Cu2+ and the continuous recognition of S2−, Arginine and Lysine.

A novel bis(salamo)-type chemosensor H 3 L was synthesized and characterized. It was found that the sensor molecule can selectively recognize Cu2+, and its L-Cu2+ is highly sensitive to the detection of S2− anion, Arginine and Lysine when dissolved in ethanol solvent. The sensor H 3 L can be used to identify a relay sensor for Cu2+, while the L-Cu2+ recognizes S2− anion, Arginine and Lysine with high selectivity and sensitivity over an acceptable physiological pH range. The detection line of the sensor molecule H 3 L is 1.02 × 10−6 M, and its binding constant to Cu2+ is 1.54 × 106 M−1. The detection line of L-Cu2+ as a sensor is calculated as 5.57 × 10−7 M, and its binding constants with S2− anion, Arginine and Lysine are 2.80 × 105 M−1, 5.32 × 106 M−1 and 5.94 × 106 M−1, respectively. The crystal structure of the Cu(II) complex [Cu 4 (L) 2 (CH 3 OH) 2 ]·2NO 3 with the sensor molecule H 3 L has been determined by single crystal X-ray crystallography. A new bis(salamo)-type tetraoxime chemosensor (H 3 L) constructed from 2-[ O -(1-ethyloxyamide)]oxime-2-naphthol and 2-hydroxy-5-methyl-benzene-1,3-dicarbaldehyde recognizes of Cu2+, Cu(NO 3) 2 ·6H 2 O with H 3 L framed by a new chemosensor Cu(II) complex [Cu 4 (L) 2 (CH 3 OH) 2 ]·2NO 3 further recognition of S2−, Arginine and Lysine. Unlabelled Image • A new bis(salamo)-type tetraoxime sensor H 3 L was synthesized. • Chemosensor H 3 L has high selectivity for Cu2+ and can be observed under naked eyes and 365 nm UV lamps. • The Cu(II) complex [Cu 4 (L) 2 (CH 3 OH) 2 ]·2NO 3 formed by H 3 L with Cu2+ can further recognize S2−, Arginine and Lysine. • L-Cu2+ chemosensor has a wide pH range, it also exhibits high sensitivities and selectivities. [ABSTRACT FROM AUTHOR]