Genfa Z, Dasgupta P K
Department of Chemistry and Biochemistry, Texas Tech University, Lubbock 79409-1061.
Anal Chem. 1992 Mar 1;64(5):517-22. doi: 10.1021/ac00029a013.
Hematin can substitute for horseradish peroxidase (HRP) as the catalyst in the determination of hydrogen peroxide using phenolic substrates such as p-hydroxyphenylacetate or p-cresol. Although the peroxidatic activity of hematin from bovine blood is not as great as HRP in terms of unit iron content, the activity per unit weight is substantially greater. Hematin is 500 times less expensive than HRP per unit peroxidatic activity. In hematin-catalyzed systems, reaction development and fluorescence measurement can both be conducted optimally in the same ammoniacal buffer. Hydroxyalkyl hydroperoxides are rapidly hydrolyzed to H2O2 at this pH and are also determined. On the other hand, for methyl hydroperoxide, hematin exhibits only approximately 10% of the sensitivity exhibited by HRP. Hematin is significantly more stable in solution than HRP. The use of hematin as catalyst and p-cresol as the substrate leads to a particularly inexpensive and sensitive system, permitting a limit of detection (LOD) of 7 nM H2O2 in a flow-injection configuration.
在使用对羟基苯乙酸或对甲酚等酚类底物测定过氧化氢时，血红素可替代辣根过氧化物酶（HRP）作为催化剂。尽管就单位铁含量而言，牛血来源的血红素的过氧化物酶活性不如HRP，但单位重量的活性却显著更高。就单位过氧化物酶活性而言，血红素的成本比HRP低500倍。在血红素催化的体系中，反应显色和荧光测量均可在同一氨性缓冲液中以最佳方式进行。在此pH值下，羟烷基氢过氧化物会迅速水解为H2O2，也可进行测定。另一方面，对于甲基过氧化氢，血红素的灵敏度仅约为HRP的10%。血红素在溶液中的稳定性明显高于HRP。使用血红素作为催化剂和对甲酚作为底物可形成一种特别廉价且灵敏的体系，在流动注射配置下可实现7 nM H2O2的检测限。
