Nano-hard template synthesis of pure mesoporous NiO and its application for streptavidin protein immobilization

Abstract

A simple and efficient immobilization of streptavidin protein (with hexa-histidine tag) onto the surface of mesoporous NiO is described. Before immobilization of streptavidin protein (with hexa-histidine tag) onto the surface of mesoporous NiO, we first synthesized well-organized mesoporous NiO by a nanocasting method using mesoporous silica SBA-15 as the hard template. Then, the well-organized mesoporous NiO particles were characterized by small angle x-ray diffraction (XRD), wide angle XRD, nitrogen adsorption/desorption, and transmission electron microscopy (TEM). TEM and small angle XRD suggested the formation of mesoporous NiO materials, whereas the wide angle XRD pattern of mesoporous NiO indicated that the nickel precursor had been transformed into crystalline NiO. The N2 sorption experiments demonstrated that the mesoporous NiO particles had a high surface area of 281 m2 g−1, a pore volume of 0.51 cm3 g−1 and a pore size of 4.8 nm. Next, the immobilization of streptavidin protein (with hexa-histidine tag) onto the surface of mesoporous NiO was studied. Detailed analysis using gel electrophoresis confirmed that this approach can efficiently bind his-tagged streptavidin onto the surface of mesoporous NiO material since the mesoporous NiO provides sufficient surface sites for the binding of streptavidin via non-covalent ligand binding with the histidine tag.

Nano-Confined Synthesis of Fullerene Mesoporous Carbon (C60-FMC) with Bimodal Pores: XRD, TEM, Structural Properties, NMR, and Protein Immobilization

“…Previously it has been reported that adsorption behavior of biomolecules depends on the type of protein molecules and nature of solid supports [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][13][14][15][16][17][18][19][20][48][49][50][51][52]. In our case dimensions of BSA are 4.7 nm × 4.7 nm × 11 nm, whereas C 60 -FMC adsorbent shows characteristics of bimodal pore size of 4.95 nm and 10-15 nm.…”

Nano/Mesoporous Carbon from Rice Starch for Voltammetric Detection of Ascorbic Acid

“…The XRD pattern of the SBA15 mesoporous silica template ( Figure 2 a) showed three well-resolved XRD peaks at low angles that could be indexed as (100), (110), and (200) reflections, indicating the formation of well-ordered hexagonal materials (p 6 mm) [ 3 , 30 , 31 , 32 , 33 , 34 , 35 ]. The XRD pattern of the corresponding RSNMC material ( Figure 2 b) exhibited a sharp peak at 2 Θ = 1.035 with a secondary hump-like reflection consistent with the formation of mesoporous carbon [ 3 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ]. The (100) peak at 2 Θ = 1.035 for the RSNMC exhibited a d-spacing of 8.53 nm, which corresponds to a unit cell parameter of 9.85 nm, whereas the two broad peaks at wide-angle XRD patterns ( Figure 2 inset) suggest the formation of an amorphous, graphitic carbon framework.…”

“…The unit cell parameter of the RSNMC replica is smaller than that of the SBA-15 template, presumably due to shrinkage during carbonization and dissolution of the host silica framework. Pore formation in the RSNMC was investigated by TEM ( Figure 3 ) and indicated organized nanopore channels [ 3 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ].…”

“…This solution was then autoclaved at 100 °C for 24 h, filtered, and dried at room temperature. Finally, calcination was performed at 550 °C for 6 h in air [ 30 , 31 , 32 , 33 , 34 , 35 ].…”

“…SBA15 mesoporous silica template (2.3 g) ( Figure 1 a) was added slowly to the starch solution with vigorous stirring to ensure a homogenous solution of template and rice starch ( Figure 1 b). Stirring overnight yielded a viscous gel that was collected in a petri dish and dried in an oven at 60 °C for 12 h to remove the solvent, then at 100 °C for 6 h, followed by 160 °C for 6 h. Carbonization was carried out under an argon flow at 900 °C for 1 h The silica template was removed by washing with 5 wt % HF solution at room temperature for 6 h [ 30 , 31 , 32 , 33 , 34 , 35 ]. The resulting nano/mesoporous carbon ( Figure 1 c) was collected by filtration, washed with ethanol, and dried in an oven at 100 °C.…”