Application Of CaAlg/CaSiO₃@SiO₂ In Protein Molecular Imprinting And High-strength Hydrogels

Bovine serum albumin（BSA）imprinted calcium alginate（Ca Alg）hydrogel membrane was prepared using BSA as a template,sodium alginate（Na Alg）as a functional monomer,and calcium chloride（Ca Cl₂）as a cross-linker.Hydrogel membranes were characterized by fluorescence microscopy,circular dichroism and fourier transform infrared spectroscopy（FT-IR）,and their swelling,adsorption and recognition properties were studied.Circular dichroism indicated that the conformation of BSA did not change during the preparing and eluting process.BSA aqueous solution with p H=6.2 and copper wire with diameter of 0.1 mm were selected to prepare relatively thin hydrogel film.The template molecule was eluted by Tris-HCl（p H=7.4）.The resulting MIP film had better adsorption effect on BSA and the maximum imprinting efficiency was 4.2.It can be seen from the cyclic voltammetry curve that recognition performance of MIP membrane to BSA was better than OVA.The BSA molecular imprinted calcium alginate hydrogel membrane was loaded onto the screw-printed carbon electrode,and the results showed that the adsorption capacity of MIP film to BSA was higher than that of non-imprinted film.OVA was used as the contrast protein to indicate MIP had good recognition performance.BSA-imprinted Ca Alg/Ca Si O₃@Si O₂ hydrogel film（MIPs）and non-imprinted Ca Alg/Ca Si O₃@Si O₂（NIPs）hydrogel film were prepared with sodium silicate（Na₂Si O₃）as reinforcement,introducing the organic-inorganic hybrid structure between Ca Si O₃@Si O₂ and Ca Alg into Ca Alg hydrogel system.It was loaded onto a modified bare carbon electrode for the recognition and detection of protein molecules.MIPs films were characterized by SEM,FT-IR and TG.Their mechanical properties and swelling properties were studied.The results showed that when the content of Na₂Si O₃ accounted for 25 wt.%of Na Alg,the mechanical properties and anti-swelling properties were satisfactory.MIPs membrane meeted both good mechanical properties and anti-swelling properties when the content of Na₂Si O₃accounted for 25 wt.%of Na Alg.Impedance diagram and cyclic voltammetry curves were used to characterize the modified electrode.According to the cyclic voltammetry curve,the electrode modified by MIPs was eluted by Tris-HCl eluent with p H=7.4,which had the best electrochemical performance and fast elution and adsorption speed.The MIPs hydrogel sensor had special recognition,good reusability and high electrode activity.High strength and toughness PAM/Ca Alg/Ca Si O₃@Si O₂ composite hydrogel membrane was prepared by introducing calcium silicate with mesoporous silica gel（Ca Si O₃@Si O₂）on the surface into polyacrylamide/calcium alginate（PAM/Ca Alg）hydrogel.The hybrid hydrogel film was characterized by SEM,TEM,Raman,XRD,circular dichroism and TG,and its mechanical properties and anti-swelling properties were investigated.The hydrogel film had the best mechanical stability when the sodium silicate content was 30 wt.%and the GDL concentration was 0.3 wt.%.The maximum stress of the hydrogel film can be maintained at 70.64%of the maximum stress under initial loading after 50 cycles of constant tensile.The energy dissipation unloading curve of the hybrid hydrogel membrane showed that the hysteresis of the hybrid hydrogel film was obvious.The longer the stretch,the more significant the hysteresis.The fracture energy of hybrid hydrogel membrane after soaking in 0.9wt.%Na Cl solution for 53 days was 9000 J/m²,which could initially replace the mechanical properties of articular cartilage.