A highly selective fluorescent sensor for the detection of Al3+ and CN- in aqueous solution: biological applications and DFT calculations

Abstract

A new "turn-on fluorescence type'' chemosensor 1 (N'1,N'2-bis((E)-2-hydroxybenzylidene)oxalohydrazide) with a simple structure was devised and synthesized. In aqueous solution, receptor 1 could efficiently detect both Al3+ and CN- at two different wavelengths. The limit of detection for Al3+ (2.0 mu M) is below the World Health Organization (WHO) guideline for drinking water (7.41 mu M). To utilize for practical and biological applications, the ability of 1 for monitoring Al3+ was tested in real water samples and living cells. In addition, 1 showed a highly selective fluorescence enhancement for CN- in the presence of other anions without any interference. The sensing mechanisms of 1 for Al3+ and CN- were supported by theoretical calculations.