Construction of a logic gate computation and visual test paper for methyl paraoxon assay based on a fluorescent europium–organic framework

Abstract

Organophosphorous pesticides pose a significant threat to public health, making its detection critical. Herein, a new fluorescent metal–organic framework, Eu-NDC, was synthesized, which possessed a 3D supramolecular structure assembled through π⋯π interactions between the naphthalene rings in its adjacent coordination-bonded layers. Then, four different products of the Eu-NDC MOF (Eu-NDC-1/2/3/4) with different morphologies were further obtained by altering the ratio of the raw materials. Among them, the fluorescence properties and BET surface area of the micro-nanoscale Eu-NDC-3 were significantly enhanced, making it the most favorable for detection. Eu-NDC-3 as a turn-off fluorescence probe for methyl paraoxon (DMNP) exhibited excellent sensitivity and selectivity, anti-interference and durability. Thus, considering these features, an intelligent logic gate was designed, showing great promise for application in smart sensing. Furthermore, an Eu-NDC-3-loaded electrospun fibrous strip was fabricated as a portable and in situ platform for visual DMNP assay.