Surface plasmon resonance assisted optical characterization of nickel ion solution and nanocrystalline cellulose-graphene oxide thin film for sensitivity enhancement analysis by Mohd Daniyal, Wan Mohd Ebtisyam Mustaqim, Fen, Yap Wing, Bashar Kamal Eddin, Faten, Abdullah, Jaafar, Mahdi, Mohd Adzir