Biosensors hydrogen peroxide determination

Potentiometry biosensors, 664 fitness for purpose, 663 hydrogen peroxide determination, 650-1 iodine-iodide buffer, 699 measurement uncertainties, 663 peroxide value, 663-4 transition metal peroxides, 1069 POV see Peroxide value POZ see Primary ozonides Precipitation waters, hydrogen peroxide determination, 637... 

B. Wang, B. Li, Z. Wang, G. Xu, Q. Wang, and S. Dong, Sol-gel thin-film immobilized soybean peroxidase biosensor for the amperometric determination of hydrogen peroxide in acid medium. Anal. Chem. 71, 1935-1939 (1999). 

J.L. Tang, B.Q. Wang, Z.Y. Wu, X.J. Han, S.J. Dong, and E.K. Wang, Lipid membrane immobilized horseradish peroxidase biosensor for amperometric determination of hydrogen peroxide. Biosens. Bioelectron. 18, 867-872 (2003). 

S. Akgol and E. Dinckaya, A novel biosensor for specific determination of hydrogen peroxide catalase enzyme electrode based on dissolved oxygen probe. Talanta 48, 363-367 (1999). 

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. 

Optical biosensors can be designed when a selective and fast bioreaction produces chemical species that can be determined by an optical sensor. Like the electrochemical sensors, enzymatic reactions that produce oxygen, ammonia, hydrogen peroxide, and protons can be utilized to fabricate optical sensors. 

Redox-based biosensors. Noble metals (platinum and gold) and carbon electrodes may be functionalized by oxidation procedures leaving oxidized surfaces. In fact, the potentiometric response of solid electrodes is strongly determined by the surface state [147]. Various enzymes have been attached (whether physically or chemically) to these pretreated electrodes and the biocatalytic reaction that takes place at the sensor tip may create potential shifts proportional to the amount of reactant present. Some products of the enzyme reaction that may alter the redox state of the surface e.g. hydrogen peroxide and protons) are suspected to play a major role in the observed potential shifts [147]. 

Figure 5.15.C shows the auxiliary manifold used for application of this sensor to the determination of hydrogen peroxide. The sample is injected into an appropriate buffer that is merged with a stream of substrate. The mixture then reaches the biosensor, where the enzymatic reaction and retention of the product formed take place. On switching the valve, the eluting stream flushes the reaction product retained in the biosensor, which is thus made ready for the next sample. In this way, H2O2 can be determined at the parts-per-billion level over a wide linear concentration range with excellent reproducibility.

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