title: Simultaneous assay of glucose, lactate, L-glutamate and hypoxanthine levels in a rat striatum using enzyme electrodes based on neutral red-doped silica nanoparticles.
abstract: An electrochemical method suitable for the simultaneous measurement of cerebral glucose, lactate, L-glutamate and hypoxanthine concentrations from in vivo microdialysis sampling has been successfully performed for the first time using a neutral red-doped silica (NRDS) nanoparticle-derived enzyme sensor system. These uniform NRDS nanoparticles (about 50 +/- 3 nm) were prepared by a water-in-oil (W/O) microemulsion method, and characterized by a TEM technique. The neutral red-doped interior maintained its high electron-activity, while the exterior nano-silica surface prevented the mediator from leaching out into the aqueous solution, and showed high biocompability. These nanoparticles were then mixing with the glucose oxidase (GOD), lactate oxidase (LOD), L-glutamate oxidase (L-GLOD) or xanthine oxidase (XOD), and immobilized on four glassy carbon electrodes, respectively. A thin Nafion film was coated on the enzyme layer to prevent interference from molecules such as ascorbic acid and uric acid in the dialysate. The high sensitivity of the NRDS modified enzyme electrode system enables the simultaneous monitoring of trace levels of glucose, L-glutamate, lactate and hypoxanthine in diluted dialysate samples from a rat striatum.
authors.affiliation: Department of Chemistry, East China Normal University, Shanghai 200062, China.
authors.forename: Fen-Fen
authors.initials: FF
authors.lastname: Zhang
authors.forename: Qiao
authors.initials: Q
authors.lastname: Wan
authors.forename: Chen-Xin
authors.initials: CX
authors.lastname: Li
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Wang
authors.forename: Zi-Qiang
authors.initials: ZQ
authors.lastname: Zhu
authors.forename: Yue-Zhong
authors.initials: YZ
authors.lastname: Xian
authors.forename: Li-Tong
authors.initials: LT
authors.lastname: Jin
authors.forename: Katsunobu
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D004563:Electrochemistry; D004566:Electrodes; D005947:Glucose / Q000032:analysis* / Q000378:metabolism; D018698:Glutamic Acid / Q000032:analysis* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D019271:Hypoxanthine / Q000032:analysis* / Q000378:metabolism; D019344:Lactic Acid / Q000032:analysis* / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology; D017072:Neostriatum / Q000378:metabolism*; D009499:Neutral Red; D010088:Oxidoreductases / Q000378:metabolism; D010316:Particle Size; D051381:Rats; D012822:Silicon Dioxide; D013696:Temperature; D013997:Time Factors
chemical_list: D009499:Neutral Red; D019271:Hypoxanthine; D019344:Lactic Acid; D018698:Glutamic Acid; D012822:Silicon Dioxide; D010088:Oxidoreductases; D005947:Glucose