Electrochemical Sensing of Food Allergen Lysozyme based on Aptamer-Molecularly Imprinted Polymer Hybrid Platform

Lysozyme is a glycoside hydrolase enzyme commonly found in body fluids such as saliva, tears, and milk [1]. Lysozyme has an important role in food industry due to its antibacterial activity. It is used as a stabilizer, shelf-life enhancer, and preventer of butyric acid formation [2].

Lysozyme is a potentially allergenic substance [3]. Even trace amounts of Lysozyme in foods can trigger adverse reactions in the immune system in sensitive individuals. Additionally, it is considered as one of the five main allergenic proteins found in the egg of the domestic chicken (Gallus domesticus) [4]. Therefore, detecting Lysozyme in food, beverage, and alcohol samples is critical to avoiding its allergenic effect.

Aptamers can bind to their targets with high affinity due to their three-dimensional conformation, similar to antibodies [6]. Molecular Imprinted Polymers (MIP) have high affinity, and superior selectivity compared to their counterparts; they are resistant to harsh conditions such as temperature, pressure, and pH changes. An important advantage that a MIP has in analysis applications is its molecular design or imprinting specificity Integration of MIP with aptamer (aptamer-MIP) can provide a hybrid system with the excellent binding specification with analyte molecules, containing the advantages of both methods.

In this study, an aptamer-MIP-based biosensor was prepared for the Lysozyme determination. Screen-printed electrodes (SPEs) (DRP-110) were modified with gold nanoparticles (AuNPs) and graphene oxide (GO) to increase conductivity and surface area. Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) were used in the optimization and surface characterization of the study. The developed Analytical applicability of the prepared aptamer-MIP biosensor was tested in different real samples.