Hybrid molecularly imprinted polymer for amoxicillin detection

The potential adverse effects of the environmental presence of antibiotics on the ecosystem demands the development of new methods suitable for accurate detection of these micropollutants in various aquatic media. An analytical method exploiting the synergistic effect of a label-free sensing platform combined with a molecularly imprinted polymer (MIP) as robust recognition element could represent an efficient tool for the real-time monitoring of antibiotics. In this work, a hybrid organic-inorganic MIP film (AMO-MIP) selective towards amoxicillin (AMO) was synthesized and integrated with a surface plasmon resonance (SPR) sensor. The film was prepared by sol-gel using methacrylamide (MAAM) as organic functional monomer, tetraethoxysilane (TEOS) as inorganic precursor, and vinyltrimethoxysilane (VTMOS) as coupling agent. The AMO-MIP film characterized with the SPR system demonstrated about 16 times higher binding capacity to AMO than corresponding reference non-imprinted polymer (NIP). AMO-MIP-modified SPR sensors could detect AMO with LoD down to 73 pM and discriminate AMO among structurally similar molecules both in buffer and in tap water. Good reproducibility was achieved for several rebinding-regeneration cycles. The sensor could be stored at room temperature for up to 6 months without losing stability.