Luminol reaction

Present research is devoted to investigation of application of luminol reactions in heterogeneous systems. Systems of rapid consecutive reactions usable for the determination of biologically active, toxic anions have been studied. Anions were quantitatively converted into chemiluminescing solid or gaseous products detectable on solid / liquid or gas / liquid interface. Methodology developed made it possible to combine concentration of microcomponents with chemiluminescence detection and to achieve high sensitivity of determination. 

Freeman T.M., Seitz W.R., Chemiluminescence fiber optic probe for hydrogen peroxide based on the luminol reaction, Anal. Chem. 1978 50(9) 1242-1246. 

If the emitting species is not a reaction-product molecule directly formed by the exergonic reaction (as is the case in the luminol reaction, for example), chemiluminescence can occur via energy transfer processes ... 

Burdo and Seitz reported in 1975 the mechanism of the formation of a cobalt peroxide complex as the important intermediate leading to luminescence in the cobalt catalysis of the luminol CL reaction [116]. Delumyea and Hartkopf reported metal catalysis of the luminol reaction in chromatographic solvent systems in 1976 [117], while Yurow and Sass [118] reported on the structure-CL correlation for various organic compounds in the luminol-peroxide reaction. 

The luminol reaction occurs under a wide variety of conditions. Specific analysis using luminol requires that the chemistry be controlled so that the CL intensity is proportional to the concentration of the species of interest. 

The luminol reaction has been used for the determination of oxidizing agents such as hydrogen peroxide, for enzymes such as peroxidase and xanthine oxidase, and for metal ions such as copper or cobalt that catalyze this CL reaction [24],... 

The relationship between CL intensity and time is expressed by a kinetic equation including the reaction rate constants and the substrate concentration. Such is the case with the specific equation for the CL of the luminol reaction, which is one of the most widely studied in this context ... 

Although the ECL phenomenon is associated with many compounds, only four major chemical systems have so far been used for analytical purposes [9, 10], i.e., (1) the ECL of polyaromatic hydrocarbons in aqueous and nonaqueous media (2) methods based on the luminol reaction in an alkaline solution where the luminol can be electrochemically produced in the presence of the other ingredients of the CL reaction (3) methods based on the ECL reactions of rutheni-um(II) tra(2,2 -bipyridinc) complex, which is used as an ECL label for other non-ECL compounds such as tertiary amines or for the quantitation of persulfates and oxalate (this is the most interesting type of chemical system of the four) and (4) systems based on analytical properties of cathodic luminescence at an oxide-coated aluminum electrode. 

The luminol reaction has also been used for the CL determination of organic substances such as penicillins [32] and tartrate ion [30] in pharmaceutical preparations by their inhibitory effect on the luminol-iodine and luminol-periodate-manganese(II)-TEA system, respectively. As can be seen from Table 1, the results were quite satisfactory. In the indirect determination of penicillins by their inhibitory effect on the luminol-iodine system, the stopped-flow technique improves the accuracy and precision of the analytical information obtained, and also the sample throughput [32], Thus, in only 2-3 s one can obtain the whole CL signal-versus-time profile and calculate the three measured parameters formation and... 

Figure 11 Typical profiles for the H202-KSCN-CuS04-NaOH-luminol reaction in the presence and absence of a vitamin B6 perturbation. Arrows in times at which oscillations were perturbed. (From Ref. 52.)...

Figure 8 Chemiluminescent (A and B) and bioluminescent (C) detections for immobilized hybridizations of PCR product. Dg, digoxigenin Bt, biotin Ad, avidin. Procedure A [30] Biotin moiety is incorporated into PCR products during the amplification reaction, using one 5 -biotinylated primer. The product is hybridized with a Dg-labeled probe and is immobilized on streptavidin-coated magnetic beads. This capture reaction is carried out for 30 min at 37°C. A permanent magnet is used to sediment the beads during washing to remove unbound DNA. By incubation with the washed beads for 45 min at 37°C, anti-Dg antibody conjugated to HRP enzyme is bound to the Dg-labeled probe, and luminol reaction is performed for CL detection. Procedure B [31] Wells of apolystyrene microtiter plate are activated with l-ethyl-3-(3-dimethylaminopropyl)-carbodiimide, and then coated with a labeled cDNA probe complementary to an internal region of the target DNA.

A FIA system has been proposed for the CL detection of phosphate based on an enzymatic reaction and the application of a subsequent luminol reaction [41], The system consists of an immobilized pyruvate oxidase column, a mixing chamber for the CL reaction, and a PMT. H202 is generated by the reaction of phosphate and pyruvate oxidase and then reacts with luminol and HRP, producing... 

CL emission. The system allows a simple determination of phosphate in 3 min with a linear range of 4.8-160 pM. Owing to its sensitivity, this method could be satisfactorily applied to the analysis of maximum permissible phosphate concentrations in natural waters [42-44], Also, the maltose-phosphorylase, mutar-ose, and glucose oxidase (MP-MUT-GOD) reaction system combined with an ARP-luminol reaction system has been used in a highly sensitive CL-FIA sensor [45], In this system, MP-MUT-GOD is immobilized on A-hydroxysuccinimide beads and packed in a column. A linear range of 10 nM-30 pM and a measuring time of 3 min were provided, yielding a limit of detection of 1.0 pM as well as a satisfactory application in the analysis of river water. 

A fiberoptic biosensor has been used for the determination of xanthine and hypoxanthine by immobilization of xanthine oxidase and peroxidase on different preactivated membranes, which were mounted onto the tip of the fiberoptic bundle [47], The hydrogen peroxide generated was measured using the luminol reaction. A linear calibration curve of the sensors occurred in the range of 1-316 nM hypoxanthine and of 3.1-316 nM xanthine, respectively, with a detection limit of 0.55 nM. 

Figure 3.39 — The sample (hydrogen peroxide/buffer) is injected into a flowing stream of water and flows through a reservoir where a small amount of luminol is cleaved from the support. The peroxide/buffer/luminol plug then enters into the cell containing the electrode. The luminol reaction proceeds and the liuninescence is measured by a PMT. (Reproduced from [76] with permission of the American Chemical Society).

Figure 4 Enzymatic reactions of BCI substrates and their chemiluminescent detection by the luminol reaction.

Fig.4.72. Diagram of the luminol reaction detector and chromatograph for analysis of trace amounts of metals (see text for details). (From ref. 200 with permission of Marcel Dekker, New York.)...

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