Luminol analytical applications

Advances have been achieved in recent years, such as the use of CL reagents as labels to derivatize and sensitively determine analytes containing amine, carboxyl, hydroxy, thiol, and other functional groups and their application in HPLC and CE [35, 36], the synthesis and application of new acridinium esters [37], the development of enhanced CL detection of horseradish peroxidase (HRP) labels [38], the use of immobilization techniques for developing CL-based sensors [39-42], some developments of luminol-based CL in relation to its application to time-resolved or solid-surface analysis [43], and the analytical application of electrogenerated CL (ECL) [44-47], among others. 

The enhanced chemiluminescense obtained with the horseradish peroxidase-H202-luminol (139) system was applied to the development of a CLD biosensor for p-iodophenol, coumaric acid (26), 2-naphthol and hydrogen peroxide. The enzyme was immobilized by microencapsulation in a sol-gel matrix. LOD for the phenolic compounds were 0.83 p,M, 15 nM and 48 nM, respectively. A remote version of the enhanced biosensor was designed by directly immobilizing the enzyme on the tip of an optical fiber. This model was used for H2O2 assay. LOD was 52.2 p,M, with RSD 4.7% (w = 4) °. A bioluminescent response was obtained for phenols with pA a > 7 in the presence of a recombinant Escherichia coli strain, DPD2540, containing a fabA luxCDABE fusion this behavior may have analytical applications. 

The analytical applications of chemiluminescence fall into three broad categories. First, there are some chemiluminescent reactions that are catalyzed by specific compounds and that can, therefore, be diagnostic for the presence or quantitation of those compounds. For example, the hydrogen peroxide oxidation of the cyclic luminescent hydrazide luminol is catalyzed by transition metal ions such as Co(II), which can thereby be detected at a 10 pM concentration in a flow injection system (B33) and even down to 1 pM when the chemiluminescence is induced ultrasonically (K19). Other transition metal ions that have been similarly detected (in the 1-10 nM range) are Cr(III) (C13), Cu(II), and Ni(II) (S26). Other... 

Safavi A, Absalan G, Bamdad F (2008) Effect of gold nanoparticle as a novel nanocatalyst on luminol-hydrazine chemiluminescence system and its analytical application. Anal Chim... 

Zhang Z, Cui H, Lai C et al (2005) Gold nanoparticle-catalyzed luminol chemiluminescence and its analytical applications. Anal Chem 77 3324—3329... 

The CL of luminol (5-amino-2,3-dihydrophthalazine-l,4-dione) was first described by Albrecht in 1928 (Albrecht 1928). Since then, luminol and its derivatives have been extensively studied and applied for analytical applications (Yamaguchi et al. 2002). 

Different CL reactions in liquid phase have been applied with analytical purposes. These include luminol, tris(2,2 -bipyridyl)ruthenium(II), lucigenin, lophine, peroxyoxa-late derivatives, acidic potassium permanganate, sulfite, gallic acid, morphine, codeine, pyrogallol acridinium esters, and others. Table 19.2 summarizes some of the commonly used CL reactions in liquid phase and their analytical application in different areas. 

Analytical applications of CL measurements based on luminol involve determination of the oxidant, or trace metal catalyst, or monitoring various enzyme-catalysed reactions which produce hydrogen peroxide, which is then determined by CL. Glucose determination using glucose oxidase ... 

Water-soluble oxalates have been described (p. 72). Their efficiency is about the same as that of luminol. It will be interesting to see whether they will find the same practical, especially analytical applications. There is a long history of applications using luminol for analytical purposes (see Chap. XIII). 

It is possible to arrange the analytical applications according to the nature of the chemiluminescent reagents such as luminol, lucigenin, Photinus luciferin etc. It is however probably more useful to discuss them under the various compounds and materials to be analyzed. 

The flow-cell design was introduced by Stieg and Nieman [166] in 1978 for analytical uses of CL. Burguera and Townshend [167] used the CL emission produced by the oxidation of alkylamines by benzoyl peroxide to determine aliphatic secondary and tertiary amines in chloroform or acetone. They tested various coiled flow cells for monitoring the CL emission produced by the cobalt-catalyzed oxidation of luminol by hydrogen peroxide and the fluorescein-sensitized oxidation of sulfide by sodium hypochlorite [168], Rule and Seitz [169] reported one of the first applications of flow injection analysis (FTA) in the CL detection of peroxide with luminol in the presence of a copper ion catalyst. They... 

Hence it is a great challenge for the analyst to develop new CL analytical systems and apply them to real samples and complicated matrices, though it would also be important to extend the applications of classical CL systems such as the luminol-based system as described in this chapter. 

Much of the study of ECL reactions has centered on two areas electron transfer reactions between certain transition metal complexes, and radical ion-annihilation reactions between polyaromatic hydrocarbons. ECL also encompasses the electrochemical generation of conventional chemiluminescence (CL) reactions, such as the electrochemical oxidation of luminol. Cathodic luminescence from oxide-covered valve metal electrodes is also termed ECL in the literature, and has found applications in analytical chemistry. Hence this type of ECL will also be covered here. 

In the early 1980s a serendipitous discovery was made when to a mixture of HRP, luminol, and hydrogen peroxide in buffer, firefly luciferin was accidentally added. The light yield of the HRP-catalyzed peroxidation of luminol was greatly enhanced. This remarkable discovery marked the beginning of a very successful analytical tool for immunoassay and all kinds of blotting (protein, DNA, and RNA) applications [16-18],... 

---