Selective recognition of atrazine by molecularly imprinted polymer membranes. Development of conductometric sensor for herbicides detection

Molecularly imprinted polymer membranes, containing artificial recognition sites for atrazine have been prepared by photopolymerisation using atrazine as a template, methacrylic acid as a functional monomer and tri(ethylene g lycol) dimethacrylate as a cross-linker. To obtain thin, flexible and mecha nically stable membranes, oligourethane acrylate was added to the monomer m ixture. Reference membranes were prepared with the same monomer mixture but in the absence of the template. Imprinted membranes were tested as a recog nition element of an atrazine-sensitive conductometric sensor. The influenc e of the polymer composition and type of solvent used as a porogen on the m agnitude of the sensor response was investigated. The sensor developed demo nstrated high selectivity and sensitivity with a detection limit of 5 nM fo r atrazine. The membranes synthesised exhibited the same recognition charac teristics over a period of six months. The time of the sensor response was 6-15 min depending on the membrane thickness. (C) 1999 Elsevier Science B.V . All rights reserved.