Core–satellite surface imprinting polymer-based pipette tip solid-phase extraction for the colorimetric determination of pyrethroid metabolite

A core–satellite-structured surface molecularly imprinted polymer has been synthesized for the enrichment of 3-phenoxybenzaldehyde by pipette tip solid-phase extraction (SPE). In a typical sol–gel process, two silane reagents as functional monomers and 3-phenoxybenzoic acid as the dummy template, the surface imprinting layer was coated on the core–satellite silica microsphere, which formed the core–satellite-structured molecularly imprinted polymer (CSMIP). Compared to the silica-based core–shell ones, this CS-MIP exhibits a stunning surface area (142 m2 g−1) in micrometer size and also overcomes the aggregation trends of core–shell structure in nanoscale. Taking potassium permanganate solution as oxidizer and indicator, the adsorbed 3-phenoxybenzaldehyde can be a quantitatively determined through redox reaction after elution. The value of maximum adsorption capacity and imprinting factor of CS-MIP were calculated to be 87.5 μg mg−1 and 2.13, respectively. These CS-MIPs were packed into commercial pipette tip as the sorbent to concentrate 3-phenoxybenzaldehyde. Under the optimum condition, a liner relationship was achieved in the range 0.200 to 1.00 μg mL−1 and the limit of detection was 81 ng mL−1. Moreover, this customized SPE device exhibits good adsorption capability after six sequential adsorption–desorption cycles, and the high recovery range of 92.2~99.7% of spiked tap water assay demonstrated its potential application for real sample analysis.