Figure 12.

(a) Luminescent intensity of the film before and after incubation in solution of different phenylalanine concentrations; and (b) the corresponding calibration curve. After incubation and exposition to UV light, singlet oxygen is produced, which reacts with ascorbate, producing H₂O₂, which quenches the luminescence; (c) Microscopic image of the interface between a part exposed to phenylalanine (right) and a part unexposed (left); (d) UV image of the phenylalanine-exposed part (left), where only the UV light (excitation) is visible, and the unexposed part (right), where the luminescence (534 nm, green) is observable. Reprinted from [112] with permission from the Korean Chemical Society.