Preparation of estriol–molecularly imprinted silica nanoparticles for determining oestrogens in milk tablets

In this paper, the molecularly imprinted polymer layer of estriol at the silica nanoparticles surface with selective recognition had been constructed. The methacryl groups of functional monomer at the silica nanoparticles surface were acted as reactive sites to induce imprinting polymerisation. The absorption capacity results showed that the molecularly imprinted polymers had an excellent combining affinity, recognition selectivity and fast kinetics. Furthermore, the molecularly imprinted polymers were successfully used as absorbent of dispersive solid-phase extraction coupled with high-performance liquid chromatography to determinate trace estriol and estradiol in milk tablets. The high recoveries yielded of 89.1–93.5% were achieved with the relative standard deviations less than 9.4%. So, the molecularly imprinted polymers are the effective absorbents for the separation and enrichment of oestrogens in the complex matrices samples.

► The orderly and compact E3-molecular imprinting layer on the MPS-modified silica surface was synthesised.
► The most binding sites formed on or near the silica nanoparticles surface, and the rapid molecular transfer was achieved.
► Gaussian software and UV analysis were used to choose functional monomer and evaluate interaction energy.
► E3-MIPs-dSPE-HPLC was successfully applied to determine the trace oestrogens in the real sample.