Chemiluminescence detection reaction

Our results demonstrate that it is possible to determine the concentration of glucose from small volumes (20 jtL) of samples having concentrations of clinical interest. In our system, the enzymatic treatment of the sample is carried out in an aqueous solution containing the imidazole buffer. Note, however, that only 1% of water is present in the chemiluminescent detection reaction performed in a large volume of acetone (2 mL). 

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. 

Anions of another group were derivatized with formation of gaseous chemiluminescing species. Chemical reaction - gas extraction has been used with chemiluminescence detection in the stream of canier gas in on-line mode. Rate of a number of reactions has been studied as well as kinetic curves of extraction of gaseous products. Highly sensitive and rapid hybrid procedures have been developed for the determination of lO, BrO, CIO, CIO, NO,, N03, CrO, CIO, Br, T, S, 803 with detection limits at the level of pg/L, duration of analysis 3 min. 

Fig. 14-3. NOj chemiluminescent detection principle based on the reaction of NO with O3.

The potential for improved chemiluminescent detection is large, since the efficiency for activation of the acceptor is less than 0.01%. A thousand-fold increase in signal could be anticipated from this reaction. 

Chemiluminescence reactions are currently exploited mainly either for analyte concentration measurements or for immunoanalysis and nucleic acid detection. In the latter case, a compound involved in the light emitting reaction is used as a label for immunoassays or for nucleic acid probes. In the former case, the analyte of interest directly participates in a chemiluminescence reaction or undergoes a chemical or an enzymatic transformation in such a way that one of the reaction products is a coreactant of a chemiluminescence reaction. In this respect, chemiluminescent systems that require H2O2 for the light emission are of particular interest in biochemical analysis. Hydrogen peroxide is in fact a product of several enzymatic reactions, which can be then coupled to a chemiluminescent detection. 

Figure 4 Enzymatic reactions of BCI substrates and their chemiluminescent detection...

Figure 11 Chemiluminescent detection for membrane hybridization of unmodified DNA target by derivatization reaction with TMPG. Procedure [15] A portion of the DNA solution is spotted on a nylon membrane. The target DNA is hybridized to its cDNA probe having a -(G)15TT(G)15TT at its 3 terminus in a hybridization buffer (pH 7.0) at 42°C for 2 h. After washing, the membrane is moistened with sodium phosphate solution (pH 10) for a few seconds, and then immersed in 0.2 M TMPG dissolved with dimethyl sulfoxide for 0.5 min at ambient temperature. The moist membrane is then dipped in dimethyl-formamide for a few seconds, and the luminescence is detected for 0.5 min.

Figure 2 illustrates the reaction mechanisms of acridinium ester label probes and alkaline phosphatase probes using dioxetane chemiluminescent detection. Table 2 summarizes approaches for labeling DNA. 

In the chemiluminescent detection of nitrogen oxides, a constant source of ozone reacts with a metered air sample containing nitric oxide. Fontijn et al. suggested that this method could also be used for ozone detection by using a constant nitric oxide source for reaction with ozone in the air sample. The ozone-nitric oxide reaction is carried out at reduced pressure, to avoid quenching the chemiluminescent reaction. Detection of the emission in the spectral r on involved (600-3,000 nm) requires using a near-infrared-sensitive photomultiplier tube. The noise of such a photomultiplier tube is reduced by cooling it to about - 20 C. ... 

The determination of total nitrogen by oxidative combustion with chemiluminescence detection is based on the following reactions ... 

Therefore, this sensor integrates a biochemical and a chemical reaction with a prior separation (dialysis) and chemiluminescence detection. The process involves the following steps (a) dialysis of the enzyme (6) enzymatic oxidation of the reagent (c) derivatization of hydrogen peroxide and d) detection of the chemiluminescence produced. Such an original approach offers several advantages over similar methodologies, namely ... 

We also examined the preservation stability of the photoimmobilized antibodies. Although the reactivity of the antibodies dropped away over a period of 10 days when they were stored at room temperature, it was maintained for about 2 months when stored at 4°C. This result is acceptable in terms of commercial viability, though further increase in stability would be preferable. We next examined the sensitivity for the immunochips. An immu-nochip usually has a two-dimensional surface, so the detection limit for antigens can be estimated from the amount of immobilized antibodies that are present. It was difficult to increase the sensitivity of a detection system which uses a photoluminescence probe. However, we succeeded in obtaining higher sensitivity for an immunochip in which we adopted a chemiluminescence detection system using an enzyme reaction. 

Detection techniques. Detection techniques for surface-based measurements of ozone include (1) UV absorption at 254 nm (2) chemiluminescence on reaction with NO (or ethene) (3) DOAS (4) TDLS and (5) wet chemical methods, mainly those involving the oxidation of I to 12 and measurement of the I2 colori-metrically or coulometrically. The wet chemical method and the principles behind DOAS and TDLS were discussed earlier and are not treated further here. 

The technique described above is not useful for removing colored peroxidase reaction products (e.g., diaminobenzidine oxidation products) from blots Thus, we avoid detection methods based on these reactions. On the other hand, peroxidase-based luminescent assays (20) do not deposit a chemical reaction product on the blot and are compatible with this erasure method (21). An example of the use of this erasure method (Section 3 3, steps 1-5) after chemiluminescent detection is shown in Fig 2. 

The use of chemiluminescence reactions for the detection of metal ions by liquid chromatography was recently reported [59,60]. The detectors made use of the chemiluminescence produced in the reaction between luminol and hydrogen peroxide which is catalyzed by transition metals. The column effluent was mixed with the reagents in order to yield the chemiluminescence. The reaction was fast and was carried out at room temperature. By varying the pH of the buffer, selectivity towards certain metals was also achieved. For example, at pH 10-11 nickel could be analyzed but lead and aluminium were inactive at pH 13-14, the converse was true [59]. Aminco-Bowman has marketed a liquid chromatographic system in which amino acids and amines are analyzed by means of the fluorescence produced on reaction with the reagent fluorescamine. Fluorescamine does not fluoresce, but it does react with primary amino groups to produce fluorescent derivatives. The reaction is instantaneous and may be carried out at room temperature, usually at pH 9. This detection system promises to be far more sensitive than the ninhydrin detection system and is much more easily adapted to HPLC. 

In Far-Western blotting the membrane is probed with another protein to detect specific protein-protein interactions (24). The reaction can be revealed using biotinylated or GST-tagged bait or probe protein followed by a streptavidin-HRP or an anti-GST-HRP chemiluminescent detection system, respectively. 

According to the review by Marques et al.,75 the most frequent pretreatment used for chromium speciation is complex formation. Extraction processes are frequently used after complex formation to extract the complexes formed prior to UV-VIS detection. Recently, the simultaneous determination of Cr(III) and Cr(VI) using an in-capillary reaction, CE separation, and chemiluminescence detection was reported with LODs (Table 7.2) for Cr(III) and Cr(VI) of 0.6 and 8 pM, respectively.32... 

Yang, W.P., ZJ. Zhang, and W. Deng. 2003. Speciation of chromium by in-capillary reaction and capillary electrophoresis with chemiluminescence detection. J. Chromatogr. A 1014 203-214. 

Al-Gailani, B.R.M., G.M. Greenway, and T. McCreedy. 2007. Miniaturized flow-injection-analysis (jiFIA) system with on-hne chemiluminescence detection based on the luminol-hypochlorite reaction for the determination of ammonium in river water. Int. J. Environ. Anal. Chem. 87 425-436. 

The principle of chemiluminescence detection is a chemical reaction forming a species in the electronically excited state that emits a photon of measurable light on returning to their ground state. 

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