title: Lipase-nanoporous gold biocomposite modified electrode for reliable detection of triglycerides.
abstract: For triglycerides biosensor design, protein immobilization is necessary to create the interface between the enzyme and the electrode. In this study, a glassy carbon electrode (GCE) was modified with lipase-nanoporous gold (NPG) biocomposite (denoted as lipase/NPG/GCE). Due to highly conductive, porous, and biocompatible three-dimensional structure, NPG is suitable for enzyme immobilization. In cyclic voltammetry experiments, the lipase/NPG/GCE bioelectrode displayed surface-confined reaction in a phosphate buffer solution. Linear responses were obtained for tributyrin concentrations ranging from 50 to 250 mg dl(-1) and olive oil concentrations ranging from 10 to 200 mg dl(-1). The value of apparent Michaelis-Menten constant for tributyrin was 10.67 mg dl(-1) and the detection limit was 2.68 mg dl(-1). Further, the lipase/NPG/GCE bioelectrode had strong anti-interference ability against urea, glucose, cholesterol, and uric acid as well as a long shelf-life. For the detection of triglycerides in human serum, the values given by the lipase/NPG/GCE bioelectrode were in good agreement with those of an automatic biochemical analyzer. These properties along with a long self-life make the lipase/NPG/GCE bioelectrode an excellent choice for the construction of triglycerides biosensor.
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, PR China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wu
authors.forename: Xueying
authors.initials: X
authors.lastname: Liu
authors.forename: Yufei
authors.initials: Y
authors.lastname: Li
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Du
authors.forename: Xia
authors.initials: X
authors.lastname: Wang
authors.forename: Ping
authors.initials: P
authors.lastname: Xu
mesh_terms: D015374:Biosensing Techniques; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D008049:Lipase / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D058608:Nanopores; D016062:Porosity; D014280:Triglycerides / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D004800:Enzymes, Immobilized; D014280:Triglycerides; D006046:Gold; D008049:Lipase
keywords: Biosensor; Immobilization; Lipase; Nanoporous gold; Triglycerides