KIH-201: A New Enhancer of Chemiluminescence in the Luminol-Hydrogen Peroxide-Peroxidase System Characterized by A High-Performance Luminometer

Abstract
We developed new phenolic enhancers of chemiluminescence in the luminol-hydrogen peroxide-horseradish peroxidase reaction. We designed, synthesized, and tested three series of phenolic enhancers as follows: 1) hydroxybenzylidene-cyclopentenediones (KIH-201, KIH-203, TX-1123, and TX-1124), 2) 4-hydroxybenzylidene-malononitriles (TX-825, TX-1121, TX-1122, TX-1840 and SF-6847), and 3) 2, 4-dichlorophenol derivative (TX-816). Luminescence measurements were performed with a new high-performance luminometer, which have a superior photon counting system (gate time: 10–100 ms) and an automatic injector (variable range: 10–190 μA). We found that the arylidene-cyclopentenedione KIH-201 [2-(4′-hydroxy-3′-methoxy-benzylidene)-4-cyclo-pentene -1,3-dione] was an effective enhancer similar to that of p-iodophenol, known as the most strong enhancer of this chemiluminescent system. This KIH-201 will facilitate the luminol - hydrogen peroxide - horseradish peroxidase reaction to be sensitive chemiluminescence.