DOI: 10.1002/elan.201600127 Development of an Electrochemical Immunoassay for the Detection of Polybrominated Diphenyl Ethers (PBDEs) Francesca Bettazzi, [a] Tania Martellini, [a] Weilin L. Shelver, [b] Alessandra Cincinelli, [a] Eudes Lanciotti, [c] and Ilaria Palchetti* [a] 1 Introduction Polybrominated diphenyl ethers (PBDEs) are a class of flame retardants that have been extensively used since the 1970s in a wide variety of products, including building materials, electronic and electrical devices, furnishings, textiles and plastics [1]. Three PBDE commercial mix- tures have been generally used in the manufacturing pro- cesses: penta-BDE, octa-BDE and deca-BDE [2]. Be- cause of their toxicity, persistence and hazardous effects on both humans and environment [3], penta-BDE and octa-BDE have been banned from use and production in the European Union since 2004, while the use of deca- BDE in electronics and electrical applications has been banned since 2008. However, despite these actions, the persistent PBDEs have been detected in outdoor and indoor air [4], water [5], wastewaters and sluge [6], soil [7] and sediments [8], waste [9], biota [10]. Their release from existing products is expected to continue for many years [11] so their presence in the environment will linger. PBDE concentrations have been also found in blood, serum, adipose tissue and breast milk from humans all over the world. The main routes of human ex- posure to PBDEs include ingestion of contaminated house dust and foods, particularly those with high fat con- tent such as fatty fish, meat and milk. Because these com- pounds have been associated with adverse effects on the immune system, thyroid function, reproductive effects and developmental neurobehavioral toxicity [3], the de- termination of these compounds in foodstuffs and the es- timation of the health risk of dietary PBDE exposure are critical. The European Commission, in 2014, announced the need to monitor the presence of PBDEs in foodstuffs [12], although critical levels have not been defined. In particular, dietary exposure assessment is focused on BDE-28, 47, 49, 99, 100, 138, 153, 154, 183 and 209 in eggs, milk and dairy products, meat, animal and vegetable fats and oils, fish and other seafood, and others [13, 14] because of their toxicity and widespread presence in the environment. Gas Chromatography coupled with Mass Spectrometry (GC/MS) is the standard technique to determine PBDEs in environmental and food samples, since the method provides accuracy, sensitivity and selectivity and individu- al congener analysis [15–17]. Abstract : Polybrominated diphenyl ethers (PBDEs) are persistent environmental substances that were commonly used as fire retardants in a wide number of commercial products. Their low reactivity, high hydrophobicity and bi- oaccumulative properties cause their ubiquity in the air, water, food and lead to extensive exposure of world pop- ulation to these compounds. The severe health problems caused by PBDEs lead them to be banned from the market. In March 2014 the European Commission issued a recommendation in which member states are requested to monitor brominated flame retardants in food, in order to evaluate human and wildlife exposure. Here, we described the development of an electrochemi- cal magnetic particle enzyme-linked immunoassay to ana- lyze PBDEs in food samples. The immunological reaction is based on a competitive scheme, using an alkaline phos- phatase labeled congener as tracer. The anti-PBDE anti- body modified magnetic particles are captured on the sur- face of carbon disposable array of sensors. The reaction extent is finally electrochemically measured by differen- tial pulse voltammetry, upon the addition of substrate. Under the optimized conditions, a limit of detection of 0.18 ng/mL with a limit of quantification of 0.30 ng/mL and a quantification range of 0.30–6.9 ng/mL, (RSD% = 12) is obtained. Results of food samples obtained from the newly developed electrochemical immunoassay are also reported. Keywords: electrochemical immunoassay · PBDEs · magnetic beads · screen-printed electrodes · GC-MS SPECIAL ISSUE [a] F. Bettazzi, T. Martellini, A. Cincinelli, I. Palchetti Dipartimento di Chimica, Università degli Studi di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino, Firenze, Italy *e-mail: ilaria.palchetti@unifi.it [b] W. L. Shelver USDA-ARS Biosciences Research Laboratory, 1605 Albrecht Boulevard, Fargo, ND 58102, USA [c] E. Lanciotti Dipartimento di Scienze della Salute (DSS), Università degli Studi di Firenze, Viale Morgagni, 48, 50134 Firenze, Italy Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/elan.201600127. www.electroanalysis.wiley-vch.de  2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Electroanalysis 2016, 28, 1 – 8 &1& These are not the final page numbers! ÞÞ Full Paper