Acridinium esters structure

While luminol and isoluminol require an oxidant plus a catalyst for initiation of the chemiluminescent reaction, esters derived from A -methyl acridinium carboxylic acid require only alkaline hydrogen peroxide (W4). Acridinium esters were first introduced by McCapra s group (M23, M25, S32), based on earlier work on the bioluminescence of the lucigenin/luciferase system (G18), and reviewed in McCapra and Beheshti (M21). From Fig. 19, one can see the structural similarity between lucigenin and a typical acridinium ester. 

Acridinium Ester Fig. 19. Structural similarity between lucigenin and an acridinium ester. 

The kinetics of light emission are those of a transient flash (see Section 2.5), where the time course is a function of the reagents and the molecular structure of the ester. The reagent composition needs to be optimized for each individual acridinium ester, and, in a recent study (Z5) on a series of novel acridinium esters, optimal reagent concentrations were found to be 100 roM NaOH and 0.015% hydrogen peroxide (Z6). 

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