Toxins 2010, 2, 382-398; doi:10.3390/toxins2040382 toxins ISSN 2072-6651 www.mdpi.com/journal/toxins Article Development of an Electrochemical Immunosensor for Fumonisins Detection in Foods Mohamad Kamal Abdul Kadir and Ibtisam E. Tothill * Cranfield University, Cranfield Health, Cranfield, Bedfordshire, MK43 0AL, UK; E-Mail: m.abdulkadir.s06@cranfield.ac.uk * Author to whom correspondence should be addressed; E-Mail: i.tothill@Cranfield.ac.uk; Tel.: +44 7500 766487. Received: 29 January 2010; in revised form: 23 February 2010 / Accepted: 19 March 2010 / Published: 24 March 2010 Abstract: An electrochemical affinity sensor for the determination of fumonisins mycotoxins (Fms) using monoclonal antibody modified screen-printed gold electrode with carbon counter and silver-silver chloride pseudo-reference electrode is reported in this work. A direct competitive enzyme-linked immunosorbent assay (ELISA) was initially developed, exhibiting a detection limit of 100 µg·L -1 for fumonisins. This was then transferred to the surface of a bare gold screen-printed electrode (SPGE) and detection was performed by chronoamperometry, monitoring the reaction of 3,3’,5,5’- Tetramethylbenzidine dihydrochloride (TMB) and hydrogen peroxide (H 2 O 2 ) catalysed by HRP at −100 mV potential vs. onboard Ag-AgCl pseudo-reference electrode. The immunosensor exhibited detection limit of 5 µg·L −1 fumonisins with a dynamic range from 1 µg·L −1 –1000 µg·L −1 . The sensor also performed well in extracted corn samples. Keywords: fumonisins; mycotoxins; screen-printed gold electrode; electrochemical immunosensor 1. Introduction In recent years, fumonisins which are mycotoxins produced by a variety of fungi of the Fusarium genus have become one of the most widely researched areas of mycotoxins contamination in food. These toxins were first isolated from a culture of F. verticillioides by Gelderblom and co-workers [1]. OPEN ACCESS