title: Fabrication of stratified nanoporous gold for enhanced biosensing.
abstract: By a dealloying/annealing/redealloying strategy, nanoporous gold (NPG) with hierarchical microstructure is fabricated for electrochemical biosensing application. The first dealloying and annealing would produce NPG/AuAg alloy composite with a large-pore NPG layer and the second dealloying would further etch the AuAg alloy part in the composite, generating a small-pore NPG layer. By using the large-pore (≈ 100 nm) layer as the glucose oxidase (GOx) container, and the small-pore (≈ 12 nm) layer as a signal producer, this novel hierarchical NPG is demonstrated to be a good support for enzyme immobilization and fabricating enzyme-based biosensors. The immobilized GOx retains ≈ 92% of the initial activity after 7 repeated use. The GOx-loaded stratified NPG biosensor can detect glucose more sensitively with a wider linear range (up to 22 mM) than normal NPG with a uniform pore size of 30-40 nm (linear range: up to 17 mM).
authors.affiliation: School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China. Electronic address: qiuhuajun@gmail.com.
authors.forename: Huajun
authors.initials: H
authors.lastname: Qiu
authors.affiliation: School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
authors.forename: Feixue
authors.initials: F
authors.lastname: Zou
mesh_terms: D015374:Biosensing Techniques / Q000379:methods* / Q000706:statistics & numerical data; D055664:Electrochemical Techniques; D004800:Enzymes, Immobilized; D005947:Glucose / Q000032:analysis; D005949:Glucose Oxidase; D006046:Gold; D053768:Metal Nanoparticles / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology; D016062:Porosity
chemical_list: D004800:Enzymes, Immobilized; D006046:Gold; D005949:Glucose Oxidase; D005947:Glucose