title: Direct electrochemistry of horseradish peroxidase immobilized on the layered calcium carbonate-gold nanoparticles inorganic hybrid composite.
abstract: A mediator-free hydrogen peroxide (H(2)O(2)) biosensor was fabricated based on immobilization of horseradish peroxidase (HRP) on layered calcium carbonate-gold nanoparticles (CaCO(3)-AuNPs) inorganic hybrid composite. The proposed biosensor showed a strong electrocatalytic activity toward the reduction of H(2)O(2), which could be attributed to the favored orientation of HRP in the well-confined surface as well as the high electrical conductivity of the resulting CaCO(3)-AuNPs inorganic hybrid composite. The hybrid composite was obtained by the adsorption of AuNPs onto the surfaces of layered CaCO(3) through electrostatic interaction. The key analytical parameters relative to the biosensor performance such as pH and applied potential were optimized. The developed biosensor also exhibited a fast amperometric response (3s), a good linear response toward H(2)O(2) over a wide range of concentration from 5.0x10(-7) to 5.2x10(-3)M, and a low detection limit of 1.0x10(-7)M. The facile, inexpensive and reliable sensing platform based on layered CaCO(3)-AuNPs inorganic hybrid composite should hold a huge potential for the fabrication of more other biosensors.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Engineering Research Center of Pesticide and Medicine Intermediate Clean Production, Ministry of Education, Key Laboratory of Molecular and Nano Probes, Shandong Normal University, Jinan 250014, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Yan
authors.initials: Y
authors.lastname: Feng
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.forename: Limin
authors.initials: L
authors.lastname: Yang
authors.forename: Linhai
authors.initials: L
authors.lastname: Zhuo
authors.forename: Bo
authors.initials: B
authors.lastname: Tang
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002119:Calcium Carbonate / Q000737:chemistry*; D003217:Conductometry / Q000295:instrumentation*; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis* / Q000737:chemistry; D007287:Inorganic Chemicals / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D004800:Enzymes, Immobilized; D007287:Inorganic Chemicals; D006046:Gold; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D002119:Calcium Carbonate