Research Article A Novel Potentiometric Sensor for Determination of Neurotoxin -N -Oxalyl-l-, -Diaminopropionic Acid Omer Isildak, 1 Furkan Saymaz, 1 Ahmet Karadag, 1 Nesrin Okumus Korkmaz, 1 and Azade Attar 2 1 Department of Chemistry, Faculty of Science and Arts, Gaziosmanpasa University, 60240 Tokat, Turkey 2 Department of Bioengineering, Faculty of Chemical and Metallurgical Engineering, Yıldız Technical University, Esenler, 34210 Istanbul, Turkey Correspondence should be addressed to Omer Isildak; omer.isildak@gop.edu.tr Received 27 February 2014; Revised 17 April 2014; Accepted 1 May 2014; Published 20 May 2014 Academic Editor: Jochen Bundschuh Copyright © 2014 Omer Isildak et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A novel potentiometric sensor based on ionophore (Cd(NH 2 CH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 NH 2 )Ag 3 (CN) 5 ) for the determination of -N-oxalyl-l-, -diaminopropionic acid (ODAP) is developed. e ODAP-selective membrane sensor demonstrates high sensitivity and short response time. e detection limit of the ODAP-selective membrane sensor is about 2 × 10 −6 mol L −1 and the response time is shorter than 6 s. e linear dynamic range of the ODAP-selective membrane sensor is between ODAP concentrations of 1.0 × 10 −2 and 1 × 10 −6 mol L −1 . e ODAP-selective membrane sensor exhibits good operational stability for at least one week in dry conditions at 4–6 ∘ C. It has a reproducible and stable response during continuous work for at least 10 h with a relative standard deviation of 0.28% ( = 18). 1. Introduction Neurolathyrism is caused by a neuroexcitatory nonpro- tein amino acid, -N-oxalyl-l-, -diaminopropionic acid (ODAP) [1–3]. is disease is characterized by a spastic para- plegia whose sporadic outbreaks have occurred at times due to the excessive consumption of the pulse Lathyrus sativus (grass pea, khesari dal, guaya, and chickling pea) especially under famine conditions in certain parts of Bangladesh, Ethiopia, Spain, Russia, and India [4–6]. e major toxic component of the pulse is ODAP, a neurotoxin amino acid [3, 4], which can potentially act as an agonist at certain glutamate receptors and [7, 8] inhibit specifically tyrosine aminotransferase [9] and chelates metals like zinc [10] that is also present in the longevity promoting Ginseng root [11]. However, the cultivation of the Lathyrus sativus, which contains high amount of ODAP, has been continuing in several parts of the world, and large populations still consume it in their daily diet [4]. Even under severe drought conditions when Lathyrus sativus has been consumed as the sole dietary source, the disease affects only less than 5% of the individuals and more than 95% always escape from any ill effects of the pulse [4, 12]. Recently, a few HPLC methods for detection of ODAP have been developed [1, 13–16]. Intensive research for devel- oping low- or zero-neurotoxin ODAP of Lathyrus sativus seeds is continuing in several institutes focusing on agricul- tural reserves [13]. e most obvious option to achieve this goal entails plant breeding and postharvest analysing. is involves processing of a large number of samples, requiring a fast and selective method for monitoring ODAP. 9-Fluorenylmethyl chloroformate (FMOC) derivatiza- tion can be used for the detection and quantitative estimation of amounts of ODAP [17]. Euerby et al. separated the D and L isomers of ODAP with o-phthaldialdehyde chiral thiols by reversed-phase chromatography, using fluorescence detection, but the procedures are time consuming [18]. Khan et al. used precolumn derivatization with phenyl isothiocyanate (PITC) [19, 20]. e most common method utilizes the reaction of o-phthalaldehyde (OPA) with 2,3- diaminopropionic acid (DAP) formed on hydrolysis of both - and -isomers of ODAP, and the derivative is detected at Hindawi Publishing Corporation BioMed Research International Volume 2014, Article ID 251653, 5 pages http://dx.doi.org/10.1155/2014/251653