Preparation of photonic-magnetic responsive molecularly imprinted microspheres and their application to fast and selective extraction of 17β-estradiol

Abstract

a b s t r a c tPhotonic-magnetic responsive molecularly imprinted microspheres (PM-MIMs) were prepared by seed polymerization, through suitable functionalization of magnetic nanoparticles for further coating with photoresponsive functional monomer and imprinted layers, and then were successfully applied to the fast and selective extraction of 17␤-estradiol (17␤-E 2 ) from real samples. The PM-MIMs possessed a sandwich micro-spherical structure containing Fe 3 O 4 core, SiO 2 middle layer, and MIPs shell with thickness of 25 nm. The PM-MIMs displayed excellent photoresponsive properties and could be rapidly separated from solutions under an external magnet. The PM-MIMs had specific affinity towards 17␤-E 2 with high adsorption capacity (Q max = 0.84 mg g −1 ) and fast binding kinetics (K d = 26.08 mg L −1 ). The PM-MIMs proved to be an ideal photoswitch with the ability of reversible uptake and release of 17␤-E 2 upon alternate 365 and 440 nm irradiation: 45.0% of 17␤-E 2 released from the PM-MIMs upon 365 nm irradiation, and 94.0% of the released 17␤-E 2 was rebound to the PM-MIMs at 440 nm. Accordingly, the PM-MIMs were applied for fast separation and extraction of 17␤-E 2 followed by HPLC-UV determination, presenting the low limit of detection (LOD, S/N = 3) and quantification (LOQ, S/N = 10) of 0.18 and 0.62 mol L −1 , respectively. The high recoveries for spiked milk powder and drinking water samples were in the range of 97.5-113.0% with relative standard deviations less than 4.4%. This study reasonably combined photonic response, magnetic separation and surface imprinting, which endowed the PM-MIMs with significant advantages of high adsorption capacity and fast binding kinetics, convenient separation and recycled use, and simple rapid eco-benign adsorption/elution processes for template molecules. Thus, the PM-MIMs based method may be a simple, rapid, convenient, cost-effective and environmentally-friendly way for simultaneous separation, enrichment and detection of trace 17␤-E 2 in complicated matrices.

Monodisperse restricted access material with molecularly imprinted surface for selective solid‐phase extraction of 17β‐estradiol from milk

“…In the first 40 min, the adsorption of 17β-E 2 increase rapidly and reach adsorption equilibrium at about 45 min. Compared with other conventional materials such as these reports (60 [29], 90 [34], 100 [36], 150 [40], 60 min [41]), adsorption rate of 17β-E 2 -RAM-MIP is significantly improved. Moreover, this also indicates that the specific imprinted cavity of 17β-E 2 -RAM-MIP decreases mass transfer resistance and facilitates recognition of 17β-E 2 .…”

“…The analytical method of the 17β-E 2 -RAM-MIP is compared with other MIPs for 17β-E 2 , as shown in Table 2, it pointed out that our established method possesses significant advantages in analysis of milk samples: the lower LOD on 17β-E 2 -RAM-MIP in this work than previous reports [29,30,34,40,41]; the superior adsorption capacity [29,30,34,35,39,41,42] and adsorption rate [29,34,40,41] on 17β-E 2 -RAM-MIP prepared by SI-RAFT polymerization than conventional synthesis; the higher recovery of 17β-E 2 -RAM-MIP in this work than that past literatures [29,34,35,42]. In addition, our method can directly extract targeted 17β-E 2 from real samples without any protein precipitation leading to effectively simplify operation process, reduce the use of organic solvents, and shorten the samples preparation time.…”

Molecular Imprinting Technology for Biomimetic Assemblies

“…Peng et al prepared photonic-magnetic responsive molecularly imprinted microspheres (PM-MIMs) by seed polymerization for selective extraction of 17β-estradiol (17β-E2) from real samples [15]. The PM-MIMs have Fe 3 O 4 core, SiO 2 middle layer, and MIPs shell showing photo-responsive properties.…”

Development of ELISA-Like Fluorescence Assay for Melamine Detection Based on Magnetic Dummy Molecularly Imprinted Polymers

“…Consequently, MIPs have been used in many fields, including solid-phase extraction [6][7][8], drug delivery [9,10], catalysis [11], and sensing [12,13]. However, the traditional methods of MIP preparation have a number of drawbacks, e.g., incomplete template removal, low rebinding capacity, poor template accessibility, slow mass transfer, and difficult solid-liquid separation [14,15].…”