Molecularly Imprinted Dual-Responsive Extraction for Avenanthramides Using Covalent Organic Frameworks Doped with Polyethyleneimine-Modified Mn-ZnS Quantum Dots

Abstract

A dual-responsive molecularly imprinted polymer (MIP) was prepared by a one-pot polymerization from covalent organic frameworks (COFs) doped with polyethyleneimine-modified Mn-doped ZnS quantum dots. Here, the polyethyleneimine-modified Mn-ZnS QDs were polymerized with COFs by a Schiff base reaction, and then they were self-assembled with functional monomers and crosslinkers to form MIPs. The MIP was used for extraction and identification of avenanthramides by fluorescence spectrophotometry and solid-phase extraction coupled with high performance liquid chromatography. The average concentration of extracted avenanthramides was 41.13 μg g−1, which was slightly higher than that obtained by extraction of chemical reagents. Spiking experiments showed that the overall recoveries ranged between 94.39 and 115.15% with a relative standard deviation range of 1.27–3.19% (n = 3). The MIPs based on COFs doped with polyethyleneimine-modified Mn-ZnS quantum dots in this work can be used for extracting and detecting Avns in oat samples.