Tang H T, Hajizadeh K, Halsall H B, Heineman W R
Department of Chemistry, University of Cincinnati, Ohio 45221-0172.
Anal Biochem. 1991 Jan;192(1):243-50. doi: 10.1016/0003-2697(91)90215-f.
The determination of reduced nicotinamide adenine dinucleotide (NADH) by electrochemical oxidation requires a more positive potential than is predicted by the formal reduction potential for the NAD+/NADH couple. This problem is alleviated by use of 2,6-dichloroindophenol (DCIP) as a redox coupling agent for NADH. The electrochemical characteristics of DCIP at the glassy carbon electrode are examined by cyclic voltammetry and hydrodynamic voltammetry. NADH is determined by reaction with DCIP to form NAD+ and DCIPH2. DCIPH2 is then quantitated by flow-injection analysis with electrochemical detection by oxidation at a detector potential of +0.25 V at pH 7. NADH is determined over a linear range of 0.5 to 200 microM and with a detection limit of 0.38 microM. The lower detection potential for DCIPH2 compared to NADH helps to minimize interference from oxidizable components in serum samples.
通过电化学氧化法测定还原型烟酰胺腺嘌呤二核苷酸(NADH)所需的电位比NAD⁺/NADH电对的形式还原电位预测值更正。使用2,6 - 二氯靛酚(DCIP)作为NADH的氧化还原偶联剂可缓解这一问题。通过循环伏安法和流体动力学伏安法研究了DCIP在玻碳电极上的电化学特性。通过与DCIP反应形成NAD⁺和DCIPH₂来测定NADH。然后通过流动注射分析结合电化学检测对DCIPH₂进行定量,在pH 7时于 +0.25 V的检测电位下进行氧化。NADH在0.5至200 μM的线性范围内测定,检测限为0.38 μM。与NADH相比,DCIPH₂的较低检测电位有助于最大限度地减少血清样品中可氧化成分的干扰。