A novel electrochemical sensor for the detection of zearalenone in food matrices using PEGylated Fe3O4 nanoparticles supported by in-silico and multidetector AF4

Abstract

It is widely known that zearalenone (ZEN) is a carcinogenic mycotoxin that is found in a wide variety of grains, cereals, and dairy products, causing cancer in both humans and animals. Thus, there is a growing demand for sensitive, selective, and inexpensive sensors that can detect toxic mycotoxins in real food samples. In this paper, the impact of PEGylated Fe3O4 nanoparticles (NPs) intercalated with carboxylic acid functionalized multiwalled carbon nanotubes (PEG-Fe3O4 NPs/cMWCNTs) was investigated for the design of an electrochemical sensor for ZEN analysis. Results showed that the nanocomposite-enhanced electrode exhibited a strong cathodic redox response of ZEN using cyclic voltammetry (CV). The developed sensor provided significantly low limits of detection and quantification of 0.34 and 1.12 fg mL−1 respectively over a calibration range of 1.00 to 10.00 fg mL−1 by differential pulse voltammetry (DPV). Excellent spike recoveries ranging from 92 to 106% were obtained for real samples of rice and corn flour. The multidetector Asymmetrical Flow Field-Flow Fractionation (AF4) measurements on the synthesized PEG-Fe3O4 NPs verified their nano-sized dimensions (rg≈ 31 nm) contributing to the exceptionally high electron transfer in DPV sensing. On the other hand, the simulated Monte Carlo (MC) adsorption studies demonstrated that the ZEN/PEG-Fe3O4 NP/cMWCNTs electrode interaction was the strongest on the GCE surface. The charge transfer was further enhanced by the combination of the strong cMWCNTs/GCE platform, due to their inherent conductive properties. The study suggests that the incorporation of the nanocomposite-enhanced electrode can be extended to prevent ZEN mycotoxin exposure.