【作者】 张文； 王彦博； 吴双； 郑卫；

【Author】 Wen Zhang;Yanbo Wang;Shuang Wu;Wei Zheng;College of Materials Science and Chemical Engineering, Harbin Engineering University;

【机构】 哈尔滨工程大学材料科学与化学工程学院；

【摘要】 将SWNTs(20 mg·mL^-1)加入到明胶(10 mg·mL^-1)溶液中,经充分搅拌、超声后转移至同轴电纺装置的内壳层注射器中。血红蛋白(75 mg·mL^-1)溶于六氟异丙醇中作为外壳层纺丝液。在接收距离为12cm,纺丝电压为16kV,流速为1.0mL·h^-1的条件下将Hb/明胶-SWNTs同轴纳米纤维固定在GC电极表面。Hb/明胶-SWNTs同轴电纺纳米纤维的芯层完全被壳层所包裹,形成了芯-壳结构（图1a）,纤维的表面均呈现为光滑无缺陷,纤维的直径大约在400-800nm范围内,同轴电纺纤维膜呈三维多孔结构（图1a）。当修饰电极在氮气饱和的PBS溶液中,获得的循环伏安曲线在-0.33V左右出现了一对明显的氧化还原峰,直接电子转移的速率常数k_s=（221.62±0.56） s^-1。另外,修饰电极对H₂O₂表现出较好的电催化活性（图1c）,对H₂O₂响应的线性范围为5-30μmol·L^-1,检测限为0.0039μmol·L^-1（S/N=3）,K_m^app=（272±4.1）μmol·L^-1,与其它纳米材料的米氏常数相比较小,表明此生物传感器的灵敏度比较高。因此,这种同轴电纺纳米纤维能够为纳米电化学生物传感器的研究提供一定的基础。更多还原

【Abstract】 The gelatin-SWNTs composites were prepared by dispersing SWNTs(20 mg·mL^-1) into gelatin solution(10 mg·mL^-1).The stirred and sonicated gelatin-SWNTs composites was used as core solution.Hemoglobin（Hb） dissolved into HFP with the concentration of 75 mg·mL^-1 was used as shell solution.Subsequently, the core and shell solution was transferred into two plastic syringe fitted with an injection rate of 1.0 mL·h^-1 using an infusion pump in the coaxial electrospinning set-up of our own designing.The distance between needle tip and bare GC electrode used as collector is 12 cm and the driving voltage is 16 kV by high voltage power supply.The resulting Hb/gelatin-SWNTs coaxial electrospun nanofibers onto the surface of bare GC electrode exhibited a clear core-shell structure（Fig.1 a） with uniform smooth surface and the diameter distribution about 400-800 nm（Fig.1 b）.Direct electron transfer of the Hb immobilized into Hb/gelatin-SWNTs coaxial electrospun nanofibers with the three-dimensional nanostructure was greatly facilitated in a 0.10 mol·L^-1 N₂-saturated phosphate buffer solution and a pair of well-defined redox peaks at-0.33 V were observed.The apparent heterogeneous electron transfer rate constant（k_s） was calculated to be（221.62±0.56） s^-1.The Hb/gelatin-SWNTs coaxial electrospun nanofibers modified electrode showed an excellent bioelectrocatalytic activity toward the reduction of H₂O₂（Fig.1 c）.The amperometric response varied linearly with the H₂O₂ concentration ranging from 5 μmol·L^-1 to 30 μmol·L^-1, with a detection limit of 0.0039 μmol·L^-1.The apparent Michaelis-Menten constant(K_m^app) was（272±4.1） μmol·L^-1 and was much smaller than that in the previous reports.It is suggested that the established biosensor exhibited fast amperometric response, high sensitivity, good reproducibility and stability.更多还原