The CuO and ZnO NPs have successfully synthesized via employing Camellia japonica leaf extract as inductive and stabilizing agent. The synthesized CuO and ZnO NPs were tested for the optical sensing of metal ions such as Li+ and Ag+ which illustrated an excellent outcome. CuO and ZnO NPs were potentially used for sensing the Li+ and Ag+ ions contamination form marine water samples through based optical sensor devices.