Products of the o-Toluidine oxidation with glucose oxidase and peroxidase
The product most likely is 2-methylnitrobenzene (3), which means that the amino group ($\ce{-NH2}$) in o-toluidine (1) is oxidized to a nitro group ($\ce{-NO2}$). The oxidation proceeds via 2-methylnitrosobenzene (2).



The formation of 2-methylnitrobenzene can be detected photometrically at $\lambda$ = 400 nm, where the aniline does not absorb.