Influence of Size and Shape of Silica Supports on the Sol–Gel Surface Molecularly Imprinted Polymers for Selective Adsorption of Gossypol

Abstract

The influence of various silica gel supports with different shapes and sizes on the recognition properties of surface molecular imprinted polymers (MIPs) was investigated. MIPs for selective recognition and adsorption of gossypol were synthesized via the sol–gel process with a surface imprinting technique on silica gel substrates. 3-aminopropyltriethoxysilane (APTES) and tetraethoxysilane (TEOS) were chosen as the functional monomer and the cross-linker. The morphology and structure of the gossypol-MIPs were characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and a standard Brunauer–Emett–Teller (BET) analysis. Results indicated that the surface imprinted polymer layer facilitated the removal and rebinding of the template, and thus, achieved fast binding kinetics. Compared with the MIPs prepared on irregularly shaped silica with a broad particle size distribution, the MIPs using regularly-shaped silica of uniform size showed higher imprinting factor (IF), and the MIP made with a relatively larger sized (60 μm) spherical silica, demonstrated higher adsorption capacity compared to the MIPs made with smaller sized, spherical silica. The MIP prepared with 60 μm spherically shaped silica, featured a fast adsorption kinetic of 10 min, and a saturated adsorption capacity of 204 mg·g−1. The gossypol-MIP had higher selectivity (IF = 2.20) for gossypol over its structurally-similar analogs ellagic acid (IF = 1.13) and quercetin (IF = 1.20). The adsorption data of the MIP correlated well with the pseudo-second-order kinetic model and the Freundlich isotherm model, which implied that chemical adsorption dominated, and that multilayer adsorption occurred. Furthermore, the MIP exhibited an excellent regeneration performance, and the adsorption capacity of the MIP for gossypol only decreased by 6% after six reused cycles, indicating good application potential for selective adsorption of gossypol.

Molecularly Imprinted Polymers for Gossypol via Sol–Gel, Bulk, and Surface Layer Imprinting—A Comparative Study

“…In the work reported by Zhao et al [40], a two-layer structure of poly(methacrylic acid)/SiO 2 bulks was designed and prepared for the detection of gossypol. The other two were developed by Zhang et al [9,41] for the recognition and adsorption of gossypol. Recently, MIPs via the sol-gel process have been prepared [42,43,44,45,46,47,48,49].…”

Simultaneous Regeneration of Bone and Nerves Through Materials and Architectural Design: Are We There Yet?

“…Molecularly imprinted materials are equipped with recognition sites that are complementary to certain substrates (template substrates) with respect to size, shape and chemical functionality. [ 323 ] They have been extensively applied to the fields of chemistry, medicine, and engineering, in processes such as catalysis, drug delivery and purification, solid phase extraction, biosensors, water treatment and proteomics. [ 324 ] With the potential to precisely combine with certain type of cells, this kind of scaffold have applications in tissue regeneration, which covers more than one tissues and requires specific distribution of different tissues within the scaffold.…”

Molecularly imprinted cryogel cartridges for the selective recognition of tyrosine

“…Recently, molecular imprinting technology has been used in various fields such as chromatography, recognition, purification, separation, and drug delivery. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Tyr-imprinted beads, [27][28][29] electrochemical, 30 and voltammetric sensors 31…”

“…MIPs may be used to create a recognition cavity of biological molecules (especially amino acids) and provide a versatile approach for its affinity and selectivity studies. Recently, molecular imprinting technology has been used in various fields such as chromatography, recognition, purification, separation, and drug delivery 8‐26 . Tyr‐imprinted beads, 27‐29 electrochemical, 30 and voltammetric sensors 31 have been developed for the selective recognition of Tyr amino acid.…”