Fluorescent turn-on detecting CN- by nucleophilic addition induced Schiff-base hydrolysis

A new chemosensor Sz based on Schiff-base group as recognition site and naphthalene as the fluorescence signal group was designed and synthesised. It could fluorescent turn-on detect cyanide (CN-) via a novel mechanism of nucleophilic addition induced Schiff-base hydrolysis. Adding the CN- into the solution of Sz could induce Sz to emit blue fluorescence at 435 nm instantly. Moreover, Sz could also colorimetric detect CN-. Upon the addition of CN-, the Sz showed dramatic color change from yellow to colorless. These sensing procedures could not be interfered by other coexistent competitive anions such as F-, AcO-, H2PO4- and SCN-. In addition, Sz showed high sensitivity for CN-, the detection limits is 3.42 x 10(-8) M of CN-, which is far lower than the WHO guideline of CN- in drinking water (less than 1.9 x 10(-6) M). The CN- test strips based on Sz could act as a convenient CN- test kits. (C) 2015 Elsevier B.V. All rights reserved.