HRP immobilization

A microsensor system for simultaneous amperometric determination of H2O2 and 02 consists of two working electrodes, one Pt counterelectrode and one WO3 reference electrode. The working electrodes are GCE covered with HRP immobilized in an elec-trodeposited membrane of polypyrrole the working electrode for 02 has in addition a layer of immobilized superoxide dismutase. Operation with this system is at pH 5.1, setting both working electrodes at —60 mV. Other operating modes are also possible. ... 

In another report, binding of IgG to anti-IgG immobilized on a Au-coated BK7 chip (sealed by PDMS) was detected by SPR [741]. Lactate was also determined using the SPR method. First, lactate was oxidized by LOX immobilized on an osmium redox polymer to produce H202. This molecule was then reduced by HRP immobilized in the same redox polymer. This surface reaction was detected by SPR [741]. 

Figure 12. Procedure for the preparation of CNT-PAMAM and GOx-HRP immobilized CNT-PAMAM (Adapted from Ref. [141]).

Figure 8 is a possible redox cycle occurring in an amperometric sensor for hydrogen peroxide involving enzyme-wiring of a typical enzyme (Horseradish peroxidase, HRP) with polyaniline. HRP immobilized on the electrode surface can be oxidized by H2O2 to compound I that contains an oxyferryl centre with the iron in the ferryl state (Fclv = O), and a porphyrin 7r cation radical, followed by further direct (mediatorless) electroreduction of compound I at the electrode surface to the initial HRP state [106], The electrode is considered as an electron donor. 

The direct voltammetry and bioelectrocatalytic activity of cytochrom c. HRP immobilized onto niobium oxide (Nb2Os) mesoporous matrix at inidium-tin oxide (ITO) electrode was investigated [282,283],The electron transfer rate constant of cytochrom c is 0.28 s"1, reflective of the intrinsic electron transfer rate. In addition mesoporous niobium... 

We studied here on accumulation of light collected by flow injection-HRP catalyzed imidazole CL. For the purpose, we have developed the CL monitoring system that consisted of a cooled CCD camera with an FFT-CCD chip as a light detector and the HRP immobilized flow-through chip as a CL reactor. We report the results of image detection and accumulation of light using the novel CL system. 

Fig. I a The FIA IV-I and II integrated biosensor systems I concentrated sample solution, 2 diluted sample solution, 3 reagent solution, 4 eightK hannel distribution valve, 5 peristaltic pump, 6 microreactors, 7 eightway injection valve, 8 temperature chamber control, 9 colorimeter, 10 micro computer, II waste, 12 coil, 13 peristaltic pump for sample dilution, 14 phosphate buffer, b The SIA integrated biosensor system I, 2 and 3 phosphate buffer solution 4 ethanol diluted sample 5 reagent solution 6 waste 7 1,000-pl micro-buiette 8 500-pl micro-burette P peristaltic pump 10 two three-way valves II six-channel distribution valve 12 colorimeter, 13 serpentine 14 AOD-immobilized microieactor 15 HRP-immobilized microreactor, 16 computer 17 Interface RS-232/RS-485...

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