In peroxidase coupled glucose methods, which reagent complexes with the chromogen?

In peroxidase-coupled glucose methods, the reagent that complexes with the chromogen is phenol. In these assays, the enzymatic reaction involves glucose oxidase converting glucose into hydrogen peroxide and gluconic acid. The produced hydrogen peroxide then serves as a substrate for the peroxidase enzyme, which catalyzes the oxidation of a chromogen in the presence of phenol.

The phenol acts as a critical component because it helps form a colored complex with the product of the enzymatic reaction, allowing for the quantitative measurement of glucose levels. This colored complex is what is ultimately detected, providing a means to measure glucose concentration in the sample. The other substances listed do not serve this specific role in the peroxidase coupling process, as they do not complex with the chromogen in the manner that phenol does.