Optical Sensing of Phenylurea Pesticides by Hydrogen Bonding with Carboxylate Dyess

Widely used phenylurea pesticides are well-known to negatively affect the environment. Herein, we studied the formation of hydrogen bonds between phenylurea pesticides and anions with the aim to develop a method that can optically sense these pesticides using carboxylate dyes. Nuclear magnetic resonance (NMR) titration experiments revealed that a hydrogen bond is formed between the urea moiety and the anion. The strengths of the formed hydrogen bonds and the absorption-spectral responses of azobenzene- and stilbene-based carboxylates to phenylurea pesticides are discussed.