title: Monodispersed silica nanoparticles as carrier for co-immobilization of bi-enzyme and its application for glucose biosensing.
abstract: A novel glucose sensing strategy by using bi-enzyme coated monodispered silica nanoparticles (SiO2) was proposed. The monodispered SiO2 was synthesized according to our previously reported seed-growth methods. Glucose oxidase (GOD) and horseradish peroxidase (HRP) were simultaneously covalent immobilized on the surface of SiO2 nanoparticles through the cross-linker of glutaraldehyde. The immobilized bi-enzyme remained their bioactivities well for the substrate reaction. Thus, the resultant SiO2-GOD/HRP nanocomposites could be used as catalyst for enzymatic substrate reactions in the presence of 3,3',5,5'-tetramethylbenzidine (TMB) as chromogenic reagent and glucose as substrate. The factors of affecting the catalytic activities of enzymes were optimized. Under optimal conditions, the absorbance at 450 nm in UV-visible spectra increased with the glucose concentration, which could be used for glucose detection with a linear range from 0.5 μM to 250 μM and a detection limit of 0.22 μM at a signal-to-noise ratio of 3σ. Considering the potential of making pills using this SiO2-GOD/HRP, the present strategy has good prospect in the clinic science and other fields in future.
authors.affiliation: State Key Laboratory of Bioelectronic, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Bioelectronic, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Bioelectronic, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, People's Republic of China. Electronic address: liusq@seu.edu.cn.
authors.forename: Songqin
authors.initials: S
authors.lastname: Liu
mesh_terms: D000042:Absorption; D001560:Benzidines / Q000378:metabolism; D055162:Biocatalysis; D015374:Biosensing Techniques / Q000379:methods*; D001786:Blood Glucose / Q000378:metabolism; D002138:Calibration; D004800:Enzymes, Immobilized / Q000378:metabolism*; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase / Q000378:metabolism*; D006735:Horseradish Peroxidase / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D012822:Silicon Dioxide / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors
chemical_list: D001560:Benzidines; D001786:Blood Glucose; D004800:Enzymes, Immobilized; C021758:3,3',5,5'-tetramethylbenzidine; D012822:Silicon Dioxide; D005949:Glucose Oxidase; D006735:Horseradish Peroxidase; D005947:Glucose
keywords: Bi-enzyme; Biosensor; Catalyst; Glucose; Silica nanoparticles