Sensors and Actuators B 227 (2016) 277–282 Contents lists available at ScienceDirect Sensors and Actuators B: Chemical jo ur nal home page: www.elsevier.com/locate/snb Polyalkoxy substituted phthalocyanines sensitive to phenolic compounds in water Dilek D. Erbahar a , Gülay Gümüs ¸ a , Özgür Pamir a , Emel Musluo˘ glu a , Vefa Ahsen a,b , Ilke Gürol a , Mika Harbeck a,∗ a TÜBITAK Marmara Research Center, Materials Institute, P.O. Box 21, 41470 Gebze, Kocaeli, Turkey b Gebze Technical University (formerly Gebze Institute of Technology), Department of Chemistry, P.O. Box 141, 41400 Gebze, Kocaeli, Turkey a r t i c l e i n f o Article history: Received 9 October 2015 Received in revised form 2 December 2015 Accepted 12 December 2015 Available online 15 December 2015 Keywords: Phthalocyanine Quartz crystal microbalance Liquid sensing Pentachlorophenol Water pollution Chemical sensor array a b s t r a c t Chemical sensors are considered a suitable technology for the detection of various chemical species in the gas and liquid phase. For liquid sensing applications there is an ongoing interest on the development of new sensing layers targeting various organic or inorganic compounds including pesticides, hydrocarbons, phenols, or other water contaminants. As sensitive materials phthalocyanines (Pc) have been found to exhibit excellent sensing performance and compounds with highly varying sorption properties and good sensing performance can be produced by chemical modifications applied to the base structure. In this work, new Pcs as sensitive materials for chemical sensors operating in water with specific selectivity and high sensitivity are described. The materials are characterized using the quartz crystal microbalance (QCM). The influence of the modifications made to the Pc core on the analyte sorption and QCM sensing properties are discussed. Materials with high sensitivities and clear preferences to certain analytes have been obtained, e.g., Pcs with polyalkoxy substituents showed high sorption preferences for compounds like pentachlorophenol and QCM sensitivities as high as 200 Hz/mg/l for PCP were obtained. The results provide new insights for new sensor material design in liquid sensing with the QCM and related sorption based sensor types. © 2015 Elsevier B.V. All rights reserved. 1. Introduction Chemical sensor technology is under investigation for the use in many chemical detection problems in water or aqueous media, including the study of water pollution by organic compounds, ions or pesticides [1–3]. A crucial part determining the performance of chemical sensors is the sensitive layer interacting with the analyte molecules and different classes of compounds have been utilized. For example, regular organic polymers or molecular imprinted polymers are reported for pesticide detection using the sorption based mass sensitive transducer quartz crystal microbalance (QCM) [4–8] and electrochemical [9,10] or optical transduction methods [10,11]. ∗ Corresponding author at: TÜBITAK Marmara Research Center, Materials Insti- tute, Barıs ¸ Mah., Dr. Zeki Acar Cad. No. 1, 41470 Gebze, Kocaeli, Turkey. E-mail addresses: dilek.dundar@tubitak.gov.tr (D.D. Erbahar), gulay.gumus@tubitak.gov.tr (G. Gümüs ¸ ), o.pamir@hotmail.com (Ö. Pamir), emel.musluoglu@tubitak.gov.tr (E. Musluo˘ glu), ahsen@gtu.edu.tr (V. Ahsen), ilke.gurol@tubitak.gov.tr (I. Gürol), mika.harbeck@tubitak.gov.tr (M. Harbeck). In terms of the choice of the sensitive material phthalocyanines (Pcs) are a potent alternative to polymers. Different modifications can be made to the Pc to govern sensitivity and selectivity includ- ing introduction of a metal ion center and various substituents. Through introduction of metal ion centers such as Co 2+ , Cu 2+ , Ni 2+ , and Zn 2+ in combination with various fluorinated substituents compounds with high sensitivity and preferences for certain pesti- cides were obtained [12,13]. Sensors for the detection of different phenols in mM concentration in aqueous solution were produced with a copper phthalocyanine having decyltosylaminomethyl groups deposited in layers using the Langmuir–Schäfer method onto a QCM crystal [14]. Besides, substituted zinc phthalocya- nine with decyltosylaminomethyl and tosylamido had been studied using optical methods in their responses to pentachlorophenol and high sensitivities and low detection limits were obtained, but data on their selectivity is not given [15,16]. In this work, a set of phthalocyanines modified with polyalkoxy and fluorinated alkyl and polyalkoxy substituents and Cu 2+ , Ni 2+ , TiO 2+ ion centers are systematically studied and characterized in their analyte sorption and sensing properties in aqueous samples using the QCM. The Pc sensors were exposed to pentachlorophenol http://dx.doi.org/10.1016/j.snb.2015.12.042 0925-4005/© 2015 Elsevier B.V. All rights reserved.