A novel electrochemical sensor for the detection of zearalenone in food matrices using PEGylated Fe3O4 nanoparticles supported by in-silico and multidetector AF4
Lyndon Naidoo, Gloria Ebube Uwaya, Florian Meier, Krishna Bisetty
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 Fe 3 O 4 nanoparticles (NPs) intercalated with carboxylic acid functionalized multiwalled carbon nanotubes (PEG-Fe 3 O 4 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-Fe 3 O 4 NPs verified their nano-sized dimensions ( r g ≈ 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-Fe 3 O 4 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.