Rational design of a novel MOF-based ternary nanocomposite for effectively monitoring harmful organophosphates in foods and the environment

Methyl parathion (MP) is a widely used organophosphate insecticide that is extremely toxic due to its ability to irreversibly inhibit acetylcholinesterase in the body and persistently accumulate in the environment. Timely detection of MP can prevent harmful residue exposure to humans. Therefore, the development of fast, efficient electrochemical methods to detect trace MP has been highly beneficial for monitoring harmful residues in foods and environment to ensure food safety and ecological conservation. Herein, a novel hybrid metal-organic framework (MOF) nanocomposite composed of Pt nanoparticles (PtNPs), multi-walled carbon nanotubes (MWCNTs), and UiO-66-NH2 (PtNPs/UiO-66-NH2/MWCNTs) was rationally designed and prepared by a facile two-step strategy for the sensitive determination of MP. The synergistic effects are illustrated in detail using XRD, XPS, FTIR, TEM, and SEM studies as well as electrochemical technologies such as CV, EIS, and DPV. In addition, the performance of the ternary nanocomposite for detecting MP was investigated by comparing it with the binary-component one. The results showed that the PtNPs/UiO-66-NH2/MWCNT-based electrochemical sensor exhibited outstanding sensitivity of 21.9 μA μM-1 cm-2, satisfactory low detection limit of 0.026 μM and wide linear range of 0.11-227.95 μM for MP analysis. Furthermore, the fabricated sensor delivered distinguished freedom from interferences, outstanding regeneration ability, and adequate recoveries for fresh foods and river water samples. In conclusion, the proposed PtNPs/UiO-66-NH2/MWCNT-based sensor provides a potentially useful analytical tool for determining hazardous residues of OPs in foods and the environment.