An Effective Label-Free Electrochemical Aptasensor Based on Gold Nanoparticles for Gluten Detection

Rossella Svigelj; Ivan Zuliani; Cristian Grazioli; Nicolò Dossi; Rosanna Toniolo

doi:10.3390/nano12060987

An Effective Label-Free Electrochemical Aptasensor Based on Gold Nanoparticles for Gluten Detection

Nanomaterials (Basel). 2022 Mar 17;12(6):987. doi: 10.3390/nano12060987.

Authors

Rossella Svigelj¹, Ivan Zuliani¹, Cristian Grazioli¹, Nicolò Dossi¹, Rosanna Toniolo¹

Affiliation

¹ Department of Agrifood, Environmental and Animal Science, University of Udine, Via Cotonificio 108, 33100 Udine, Italy.

Abstract

Nanomaterials can be used to modify electrodes and improve the conductivity and the performance of electrochemical sensors. Among various nanomaterials, gold-based nanostructures have been used as an anchoring platform for the functionalization of biosensor surfaces. One of the main advantages of using gold for the modification of electrodes is its great affinity for thiol-containing molecules, such as proteins, forming a strong Au-S bond. In this work, we present an impedimetric biosensor based on gold nanoparticles and a truncated aptamer for the quantification of gluten in hydrolyzed matrices such as beer and soy sauce. A good relationship between the R_ct values and PWG-Gliadin concentration was found in the range between 0.1-1 mg L^-1 of gliadin (corresponding to 0.2-2 mg L^-1 of gluten) with a limit of detection of 0.05 mg L^-1 of gliadin (corresponding to 0.1 mg L^-1 of gluten). The label-free assay was also successfully applied for the determination of real food samples.

Keywords: aptamers; aptasensor; beer; electrochemical impedance spectroscopy; food allergen; gluten; gold nanoparticles; impedimetric biosensor; soy sauce.