Hydrogen peroxide

About: Hydrogen peroxide is a research topic. Over the lifetime, 42583 publications have been published within this topic receiving 1043732 citations. The topic is also known as: H2O2 & dioxidane.

Utilizing a CdTe Quantum Dots−Enzyme Hybrid System for the Determination of Both Phenolic Compounds and Hydrogen Peroxide

Abstract: In this paper, we attempt to construct a simple and sensitive detection method for both phenolic compounds and hydrogen peroxide, with the successful combination of the unique property of quantum dots and the specificity of enzymatic reactions. In the presence of H2O2 and horseradish peroxidase, phenolic compounds can quench quantum dots' photoluminescence efficiently, and the extent of quenching is severalfold to more than 100-fold increase. Quinone intermediates produced from the enzymatic catalyzed oxidation of phenolic compounds were believed to play the main role in the photoluminescence quenching. Using a quantum dots−enzyme system, the detection limits for phenolic compounds and hydrogen peroxide were detected to be ∼10-7 mol L-1. The coupling of efficient quenching of quantum dot photoluminescence by quinone and the effective enzymatic reactions make this a simple and sensitive method for phenolic compound detection and great potential in the development of H2O2 biosensors for various analytes.

The nature of heme/iron-induced protein tyrosine nitration

Abstract: Recently, substantial evidence has emerged that revealed a very close association between the formation of nitrotyrosine and the presence of activated granulocytes containing peroxidases, such as myeloperoxidase. Peroxidases share heme-containing homology and can use H 2 O 2 to oxidize substrates. Heme is a complex of iron with protoporphyrin IX, and the iron-containing structure of heme has been shown to be an oxidant in several model systems where the prooxidant effects of free iron, heme, and hemoproteins may be attributed to the formation of hypervalent states of the heme iron. In the current study, we have tested the hypothesis that free heme and iron play a crucial role in NO 2 -Tyr formation. The data from our study indicate that: ( i ) heme/iron catalyzes nitration of tyrosine residues by using hydrogen peroxide and nitrite, a reaction that revealed the mechanism underlying the protein nitration by peroxidase, H 2 O 2 , and NO \begin{equation*}{\mathrm{_{2}^{-}}}\end{equation*}; ( ii ) H 2 O 2 plays a key role in the protein oxidation that forms the basis for the protein nitration, whereas nitrite is an essential element that facilitates nitration by the heme(Fe), H 2 O 2 , and the NO \begin{equation*}{\mathrm{_{2}^{-}}}\end{equation*} system; ( iii ) the formation of a Fe(IV) hypervalent compound may be essential for heme(Fe)-catalyzed nitration, whereas O \begin{equation*}{\mathrm{_{2}^{{\bullet}-}}}\end{equation*} (ONOO − formation), • OH (Fenton reaction), and compound III are unlikely to contribute to the reaction; and ( iv ) hemoprotein-rich tissues such as cardiac muscle are vulnerable to protein nitration in pathological conditions characterized by the overproduction of H 2 O 2 and NO \begin{equation*}{\mathrm{_{2}^{-}}}\end{equation*}, or nitric oxide.