电催化测定烟酰胺腺嘌呤二核苷酸——以聚亚甲基蓝-碳纳米管修饰电极作为工作电极

制备了聚亚甲蓝-碳纳米管修饰的玻碳电极（PMB-SWCNT’s／GCE），并研究了烟酰胺腺嘌呤二核苷酸（NADH）在此电极上的电化学行为。结果表明：此修饰电极对NADH表现出协同电催化作用和较好的响应性能。在pH7．0的磷酸盐缓冲溶液中可观察到NADH氧化峰电位的正移及其峰电流的增加，当NADH的浓度在5．0×10^-6～7．0×10^-4mol·L^-1范围内，与相应的氧化峰电流值之间存在线性关系。方法的检出限（3s／N）为1．4×10^-6mol·L^-1，所提出的方法应用于生物材料样品中NADH的直接测定，测得方法的平均回收率为99．5％。

Layered transition-metal hydroxides for alkaline hydrogen evolution reaction

Hydrogen is a promising sustainable energy to replace fossil fuels owning to its high specific energy and environmental friendliness.Alkaline water electrolysis has been considered as one of the most prospective technologies for large scale hydrogen production.To boost the sluggish kinetics of hydrogen evolution reaction(HER)in alkaline media,abundant materials have been designed and fabricated.Herein,we summarize the key achievements in the development of layered transition-metal hydroxides[TM(OH)x]for efficient alkaline HER.Based on the structure of TM(OH)x,the mechanism of synergistic effect between TM(OH)x and HER active materials is illuminated firstly.Then,recent progress of TM(OH)x-based HER catalysts to optimize the synergistic effect are categorized as TM(OH)x and active materials,including species,structure,morphology and interaction relationship.Furthermore,TM(OH)x-based overall water splitting electrocatalysts and electrodes are summarized in the design principles for high activity and stability.Finally,some of key challenges for further developments and applications of hydrogen production are proposed.

基于Cu^(2+)和碳纳米管纳米复合物的过氧化氢生物传感器测定过氧化氢

目的将Cu2+和碳纳米管(MWNTs)固定于脱氧核糖核酸(DNA)和聚丙烯胺(PAA)中,形成MWNTs/Cu2+-DNA/PAA纳米复合物,并用此纳米复合物构建了一种新的过氧化氢生物传感器。方法将该纳米复合物修饰玻碳电极应用于过氧化氢的测定。结果 Cu2+和MWNTs之间对过氧化氢的还原具有协同电催化作用。在pH=5.0的磷酸盐缓冲溶液中,与DNA/PAA复合物中只存在Cu2+或MWNTs的复合物修饰玻碳电极相比,对过氧化氢的还原电催化稳态电流分别提高了约7倍和2.5倍。所制备的生物传感器对过氧化氢的线性范围为5.0μmol/L^4 mmol/L,检测下限为2.5μmol/L(S/N=3)。结论在电极表面涂覆一层Nafion膜可以有效消除抗坏血酸、尿酸对过氧化氢的测定影响。这种新型传感器的优越性在于它可以克服天然酶易失活、不稳定的缺点而具有良好的重现性与稳定性。