Gold nanoparticle–mesoporous silica sheet composites with enhanced antibody adsorption capacity

Abstract

A notably high-capacity antibody adsorbent was demonstrated using dispersed gold nanoparticles immobilised on a mesoporous silica sheet. The mesoporous silica sheet (MPS sheet) was prepared via a dual-templating method using tetraethoxysilane and 3-aminopropyltriethoxysilane as the silica framework materials. Gold nanoparticles were loaded on the amino-functionalised surface of the MPS sheet via deposition-precipitation using HAuCl 4 as the Au colloid precursor and then crystallised via calcination. 10 The properties of the gold nanoparticle-silica composite and the dispersion of the nanoparticles were characterised using transmission electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction analyses. The surface characteristics of gold nanoparticle composite materials calcined at different temperatures were also evaluated using Fourier transform-infrared spectra, X-ray photoelectron spectroscopy and thermogravimetry data. The mesoporous silica-gold nanoparticle composite sheet 15 crystallised at 550 °C (sheet-Au-550) was mesoporous in character (pore diameter = 3.8 nm) with a BET surface area of 258.0 m 2 g -1 . With respect to antibody adsorption, the sheet materials had a relatively higher capacity than the typical cylindrical mesoporous silica, and sheet-Au-550 exhibited strong performance (maxim adsorption quantity Q Max = 0.26 mg IgG/mg carrier). In addition, the IgG adsorption equilibrium for sheet-Au-550 fit the Langmuir isotherm model better than the Freundlich plot model. 20 These results will be very useful for the design of adsorption materials for biomolecules, such as antibodies. 65 biomolecules. Researchers have also demonstrated improvement of antibody-antigen immunosensor sensitivity using colloidal Au. 24 Antibody-immobilised silica-coated gold nanorods and nano-shells have also been applied to biomedical applications. 25,26

One-Step Surface Immobilization of Protein A on Hydrogel Nanofibers by Core-Shell Electrospinning for Capturing Antibodies

“…The result was fitted better with the Langmuir model, where one molecule adsorbs on each adsorption site of the surface until a fully adsorbed monolayer is obtained. This is described by the following formula [ 31 , 32 ]: where C is the concentration of the antibody solution added, q is the amount of adsorbed antibody calculated from the concentration of the eluted antibody solution, q max is the concentration of the PA adsorption site on the fiber, and K is the dissociation constant between PA and antibody. Fitting the experimental results to Equation (1), q max , the adsorption site of PA, and K , the dissociation constant, in PA-antibody adsorption were obtained.…”