Label-free electrochemical aptasensing platform based on TiO2-CNF incorporated Au-PdNPs for detection of peanut allergen Arah1 in real food samples

Abstract

In this study, we aimed to develop a sensitive and selective label-free aptasensor to determine Arah1 electrochemically in real food samples. For this purpose, the multilayer consisting of titanium (IV) oxide–carbon nanofiber (TiO₂-CNF) nanocomposite and Au-PdNPs bimetallic nanostructures were successively modified on the screen-printed graphite electrode (SPE) surface. Then, the thiol-linked Arah1 aptamer was immobilized onto the modified SPE, and Arah1 was incubated onto the aptamer-modified biosensing surface to complete the biorecognition process. Surface characterization of the electrochemical aptasensors was monitored using scanning electron microscopy (SEM), X-ray photoelectron spectrometry (XPS), cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Under the optimized conditions, a wide linear range between 0.25–1000 pg/mL was obtained to determine Arah1 with low LOQ and LOD values as 0.115 pg/mL and 0.035 pg/mL, respectively. In addition, the novel aptasensing platform designed for Arah1 exhibited excellent reproducibility, repeatability, and high selectivity in the presence of different proteins. In light of these results, the proposed sensitive Arah1 aptasensor can be successfully applied to determine the peanut allergen Arah1 in bread and peanut butter samples.