摘要
采用滴涂法制备了碳纳米管(MWNTs)/壳聚糖(CHIT)修饰玻碳电极(GCE),较为明显的使还原型辅酶Ⅱ(NADPH)在裸GCE上的氧化电势从700mV降低到修饰电极上的380mV,并且明显增大了催化电流。氧化电流与NADPH浓度在0.08～2.60mmol/L范围内呈线性关系;检出限为18.3!mol/L。利用此修饰电极,采用计时电流i-t法,在谷胱甘肽还原酶(GR)催化"氧化型谷胱甘肽+NADPH"生成"还原型谷胱甘肽+NADP+"反应中,通过检测NADPH在电极上催化电流的变化情况,分析了不同酸度和浓度下的Al3+和nano-Al13的加入对GR酶促反应初速率V0、米氏常数Km及反应最大速率Vmax的影响。
We prepared a MWNTs/chitosan modified bare GCE that obviously decreased the overpo- tential of reduced coenzyme Ⅱ NADPH from 700 rnV at GCE to 380 mV at the modified electrode, meanwhile increased the catalytic current apparently. Oxidation current of NADPH is proportional to NADPH concentration in the range of 0.08-2.60 mmol/L with the lower detection limit for 18.3 μmol/L. In the catalytic reaction of glutathione reductase（GR）, we used the modified electrode to monitor the change of oxidation current of NADPH based on amperometic i-t curve, the enzyme activity could be represented by the persisting decrease in the limiting steady-state oxidation current of NADPH. The effects of A13＋ and nano-Al13 on the activity of GR-catalyzed reactions under different pH values and different aluminum concentrations were studied. The results showed that the AP＋ and nano-A113 could inhibit the activity of enzyme GR in aqueous solution.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2012年第4期584-588,共5页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金(Nos.20875047,20902048)
江苏高校优势学科建设工程资助
