Common food contaminants include pathogens, toxins, pesticides, veterinary drugs and
illegal additives, while common allergens are mainly proteins [1]. Food induces different
hypersensitivity reactions in allergic people when humans are exposed to harmful allergens.
Generally, patients with food allergies undergo prophylactic practices as there is no medical
treatment. Food allergy affects 1-10 % of the population and reports show that its prevalence
in children increased by 50% between 1997 and 2011 [2]. Symptoms can occur from minutes
to hours after exposure, and may include difficulty in breathing, low blood pressure, itchy
rash, swelling of the tongue, and life-threatening systemic reaction called anaphylaxis.
Ara h1, 2, 3 and 6 are considered to be major allergens found in peanuts which trigger to an
immunological response in more than 50% of the allergic population representing the first
leading cause of anaphylactic fatalities worldwide [3]. ELISA is the most commonly used
method for determining low levels of food allergens in food (ingredients, processed foods
and beverages) [4], but lacks of simplicity and reduced costs and oftentimes leads to delays
in results acquisition. Since functional foods and new food manufacturing technologies are
emerging, there is an ongoing demand for analytical strategies for on-site sensitive detection
of food allergens.
This poster presents a strategy for the determination of the presence of allergens in food
products by enabling an electrochemical approach based on DNA strands. The affinity
reaction between the DNA strands and Ara h1, followed by conformational and structural
changes in the recognition layer, was triggered by means of electrochemical mediators
labelled at the DNA sequence. Several strategies were addressed to diminish the protein
fouling at the electrode surface and obtain the optimal sensing parameters. Each step of
electrode modification was characterized by electrochemical techniques such as cyclic and
differential pulse voltammetry, and electrochemical impedance spectroscopy. Applications
on food samples will be presented.

References
[1] Melinte G, Hosu O, Cristea C, Marrazza G. TrAC Trends in Anal. Chem. 2022;154,
116679.
[2] Facts and statistics|food allergy research. www.foodallergy.org/life-with-foodallergies/
food-allergy-101/facts-and-statistics.
[3] Mueller GA, Maleki SJ, Pedersen LC. Curr Allergy Asthma Rep. 2014;14(5):429.
[4] Hosu O, Selvolini G, Marrazza G. Curr Opin Electrochem. 2018;10:149–56.