An investigation of template anchoring strategy for molecularly imprinting materials based on nanomagnetic polyhedral oligomeric silsesquioxanes composites

Abstract

A template anchoring strategy for high performance molecularly imprinting materials (MI-materials) was displayed in the present work, which involved efficient usage of template molecules with the aid of functional monomer grafted on the support. The imprinting polymerization process was carried out on the surface of carboxyl functionalized Fe₃O₄@POSS (Fe₃O₄@POSS-COOH) anchoring with tetracycline templates as a demonstration. In this strategy, Fe₃O₄@POSS-COOH was first prepared via a simple copolymerization between methacrylic acid (MAA) and the residual end vinyl groups of Fe₃O₄@POSS. The carboxyl groups immobilized on Fe₃O₄@POSS surface can drive tetracycline templates into the formed polymer layers through hydrogen interactions between tetracycline and the functionalized monomer. The occupation of assembled tetracycline templates on the surface of Fe₃O₄@POSS-COOH directed the selective occurrence of imprinting polymerization through copolymerization of vinyl end groups of Fe₃O₄@POSS, leading to the formation of tetracycline imprinted nanocomposite with a high density of effective recognition sites. The obtained MI-material exhibited high capacity and favorable selectivity towards tetracycline antibiotics. By applying the proposed MI-material as magnetic solid phase extraction adsorbents, four tetracyclines were prominently enriched from milk samples. The MI-material based analytical platform was sensitive for the determination of TCs in milk samples with LOD values in the range of 2.23-26.84 ng mL^-1 and recoveries ranged from 86.2% to 105.7%. This work proposed an improved strategy for preparing efficient MI-materials based on Fe₃O₄@POSS, which provides a new insight into the chemical properties of Fe₃O₄@POSS.

Keywords: Fe(3)O(4)@POSS; Molecularly imprinting materials; Template anchoring; Tetracycline.