A variety of fluorescent probes are? proposed to monitor the intracellular copper content, So far, none of the probes have been evaluated for their potential to inhibit copper-associated intracellular oxidative stress. Herein, we studied the ability of a fluorescent copper probe, OBEP-CS1, to inhibit intracellular oxidative stress associated with an amyloid beta (A beta) peptide-copper complex. The data showed that OBEP-CS1 completely inhibits the copper-catalyzed oxidation as well as decarboxylation/deamination of A beta 1-16. Moreover, the cell imaging experiments confirmed that OBEP-CS1 can inhibit A beta-Cu-II-catalyzed reactive oxygen species production in SH-SYSY cells. We also demonstrated that A beta 1-16 peptide can bind intracellular copper and thereby exert oxidative stress.