Zhang Fen-Fen, Wan Qiao, Li Chen-Xin, Wang Xiao-Li, Zhu Zi-Qiang, Xian Yue-Zhong, Jin Li-Tong, Yamamoto Katsunobu
Department of Chemistry, East China Normal University, Shanghai 200062, China.
Anal Bioanal Chem. 2004 Oct;380(4):637-42. doi: 10.1007/s00216-004-2804-x. Epub 2004 Oct 2.
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.
首次成功运用中性红掺杂二氧化硅（NRDS）纳米颗粒衍生的酶传感器系统，实现了一种适用于从体内微透析采样同时测量脑葡萄糖、乳酸、L-谷氨酸和次黄嘌呤浓度的电化学方法。这些均匀的NRDS纳米颗粒（约50±3纳米）通过油包水（W/O）微乳液法制备，并采用透射电子显微镜（TEM）技术进行表征。掺杂中性红的内部保持其高电子活性，而外部纳米二氧化硅表面可防止介体渗漏到水溶液中，并表现出高生物相容性。然后将这些纳米颗粒分别与葡萄糖氧化酶（GOD）、乳酸氧化酶（LOD）、L-谷氨酸氧化酶（L-GLOD）或黄嘌呤氧化酶（XOD）混合，并固定在四个玻碳电极上。在酶层上涂覆一层薄的Nafion膜，以防止透析液中抗坏血酸和尿酸等分子的干扰。NRDS修饰的酶电极系统具有高灵敏度，能够同时监测大鼠纹状体稀释透析液样品中的微量葡萄糖、L-谷氨酸、乳酸和次黄嘌呤。
