In order to emit less contaminants into the environment, and at the same time produce healthier foods that are free of those contaminants, all production systems should be investigated, i.e. whether improvements can be made. Within the Food-Agro industry, pesticides that are harmful to bees and insects are of concern and an example of such environmental contaminants. Not only because they cause a direct decrease of biodiversity, but also crop loss due to decreased pollination, which has a direct economic impact. Another actual example is the presence of antibiotics in dairy products. As both, the use of antibiotics and their presence in the food chain are related to antibiotic resistance of bacteria, complicating treatments for infectious diseases.

In the Biosensors & Bioassays department at Wageningen Food Safety Research (WFSR, formerly known as RIKILT Wageningen UR) a wide range of detection formats are explored for the development of food and feed safety, food fraud, food authenticity, food allergy and environmental contamination immunoassays.

There is a strong focus on the development of xMAP based assays on the MAGPIX® planar array analyzer. The easily transportable MAGPIX® analyzer can be taken from the laboratory into the field and implemented for portable on-site analysis. The point of need testing can be carried out in a simple laboratory set-up e.g. the back of a car. This can be of great importance since raw materials for food production can already be pre-screened prior to entering the food and feed production or a supply chain. Within WFSR, the xMAP technology is used for the multiplex detection of many different targets. This ranges from proteins, e.g. allergens, growth promotors, and fraud proteins, to very small molecules like mycotoxins, antibiotics, pesticides, tranquilizers, marine toxins and antiparasitics. The detection assays developed for these target analytes, and target analyte groups, cover a wide range of different food and environmental matrices, e.g. cereals, milk, honey, plants and water. Additionally, the xMAP technology is used to build single assays for high through put on-site analysis, e.g. the detection of fipronil in manure and eggs. Recently, a 13-plex for antibiotics was developed and validated for the detection of over 80 antibiotics in e.g. milk, urine and (drink) waters. However, in some cases, the availability of antibodies seriously hampers the development of a multiplex assay. This is especially the case for pesticides (>1000), where only a limited amount of antibodies are available. This complicates the development of broad range pesticides screening assays. Despite that, dedicated xMAP assays focusing on certain classes of pesticides are feasible and we recently started to work on the development of xMAP assays that focus on pesticides that have serious detrimental effects on bees.

In all the relevant fields of food safety and environmental research, biosensor methods are developed at WFSR using xMAP technology. It is considered as a fast and robust standard for ultiplexing, which is highlighted by combing previously developed unique multiplex assays for contaminants and animal drugs for different matrices. The xMAP technology is further used for benchmarking other multiplex technologies and newly developed prototypes of multiplexing equipment.