Quinoline-based hydrazone derivative as a biocide chemosensor: synthesis and sensing studies

Abstract

Tributyltin (TBT) is an organic biocide used on antifouling paints to avoid biofouling on boats and submersed structures. It is toxic to a variety of aquatic organisms and was banned by the Rotterdam Convention in 1998. TBT sensing is an important issue as the biocide is still affecting aquatic environments as some countries did not sign the convention and are still using it. Currently, TBT monitoring methods are based on sampling and laboratory analysis, which is expensive, time-consuming, and require expert users. Therefore, a new simple and fast TBT sensing method would be of high interest. In this work, a new quinoline-based hydrazone derivative was synthesized by a condensation reaction in 67% yield. The new compound was characterized by the usual spectroscopic and spectrometric techniques. The preliminary chemosensory study of the hydrazone derivative in the presence of TBT in acetonitrile solution resulted in a color change from colorless to red together with the appearance of fluorescence. This interaction was confirmed by spectrophotometric and spectrofluorimetric titrations, which revealed that 17 equivalents of TBT led to the maximum optical signal in terms of fluorescence intensity and absorbance.