▎ 摘　　要

NOVELTY - Preparing ionic liquid covalently-modified graphene-exfoliated hydrotalcite-like composite fixed-protein modified electrode involves utilizing a base electrode layer and an ionic liquid covalently modified graphene-exfoliated hydrotalcite-like composite fixed egg layer. The ionic liquid covalently-modified graphene-exfoliated hydrotalcite composite material is prepared by covalently modifying an oxidized graphene-exfoliated hydrotalcite complex with amino-functionalized ionic liquid through epoxy ring-opening. USE - Method for preparing ionic liquid covalently-modified graphene-exfoliated hydrotalcite-like composite fixed-protein modified electrode used for preparation of electrochemical sensor and detection of trichloroacetic acid (claimed). ADVANTAGE - The method enables to prepare ionic liquid covalently-modified graphene-exfoliated hydrotalcite-like composite fixed-protein modified electrode that has synergistic effect on ionic liquid, ink and hydrotalcite-like sheet to improve direct electrochemical and electrocatalytic performance of hemoglobin, has improved conductivity, dispersibility and biocompatibility and the trichloroacetic acid sensor has low detection limit, wide detection range and small Michaelis-Menten constant. DETAILED DESCRIPTION - Preparing ionic liquid covalently-modified graphene-exfoliated hydrotalcite-like composite fixed-protein modified electrode involves utilizing a base electrode layer and an ionic liquid covalently modified graphene-exfoliated hydrotalcite-like composite fixed egg layer. The ionic liquid covalently-modified graphene-exfoliated hydrotalcite composite material is prepared by covalently modifying an oxidized graphene-exfoliated hydrotalcite complex with amino-functionalized ionic liquid through epoxy ring-opening. The protein is fixed by a drop coating method that forms composite protein layer on ionic liquid covalently-modified graphene-exfoliated hydrotalcite composite material. The exfoliated hydrotalcite plate is cobalt-aluminum which is denoted as ELDH. The protein is bovine hemoglobin which is denoted as Hb. The base electrode is an ionic liquid modified carbon paste electrode which denoted as CILE, the graphene oxide is denoted as GO and the graphene is denoted as GR. The ionic liquid is 1-butyl-3-aminopropylimidazole tetrachloroborate which is denoted as IL. The preparation method involves preparing GO-ELDH nano hybrid material from graphene oxide which is prepared by Hummer's method. The obtained graphene oxide is dispersed in formamide to prepare the concentration of 1 mg/ml. The obtained solution is centrifuged at 3000 revolutions/minute for 10 minutes to remove the peeled off graphene oxide. The graphene oxide dispersion is mixed with equal volume of 1 mg/ml ELDH formamide colloid solution and the mixture is sealed at room temperature under stirring conditions for 12 hours. The obtained solution is centrifuged at 5000 revolutions/minute for 10 minutes to obtain brown-black precipitates of GO-ELDH hybrids. The IL-GRELDH hybrid material is prepared by mixing 10-40 mg of GO-ELDH hybrid in deionized water to make a concentration of 0.5 mg/ml. The obtained solution is then added with 5-20 mg of IL and 5-20 mg of potassium hydroxide and the solution is carried for ultrasonic treatment for 30 minutes. The particles after ultrasonic dispersion are heated at 80 degrees C for 24 hours with a speed of 4000 revolutions/minute and then the solution is centrifuged for 5 minutes. The obtained product is washed with water and ethanol 3 times to obtain black solid particles of IL-GR-ELDH hybrid. The graphite powder and the ionic liquid N-butylpyridinium hexafluorophosphate are added to the mortar in the mass ratio of 2:1 and the mixture is homogeneously mixed with heating at 80 degrees C. The obtained powdery mixture is added dropwise with 1 ml liquid paraffin and then the mixture is fully ground and filled into a 4 mm diameter glass tube. The copper wire is inserted into the tube as a wire and the solid mixture in the glass tube is compacted to obtain carbon ionic liquid electrode. The surface of the electrode is polished smooth before use. The IL-GR-ELDH hybrid material obtained is dissolved into deionized water to prepare a concentration of 0.5 mg/ml and 12 mu l of the obtained slurry is applied to the surface of carbon ionic liquid electrode and the surface is naturally air-dried. The 8-12 mu l of aqueous hemoglobin solution having a concentration of 10 mg/ml is dripped onto the electrode and the surface is dried naturally, after that 1.0 mg/ml chitosan acetic acid solution is dropwise added to the electrode and dried naturally to obtain GR-ELDH-Hb/carbon ionic liquid electrode biodegradable electrode. The IL has structural formula (I).