Figure 10.

Evidence of oxygen singlet production. (a) Intrinsic light emission by the reaction of 0.25 mM Tau-NHBr with 5 mM H₂O₂ in 50 mM phosphate buffer, pH 7.0; (b) Melatonin-mediated light emission by the reaction consisting of 0.25 mM Tau-NHBr with 5 mM H₂O₂ and 1 mM melatonin in 50 mM phosphate buffer, pH 7.0 (complete system); (c) HPLC analysis of the reaction mixture and evidence of the formation of AFMK (peak at 6 min) obtained by comparison with a pure AFMK.