Label-Free SERS Analysis of Serum Using Ag NPs/Cellulose Nanocrystal/Graphene Oxide Nanocomposite Film Substrate in Screening Colon Cancer oleh Jie Li, Qiutian She, Wenxi Wang, Ru Liu, Ruiyun You, Yaling Wu, Jingzheng Weng, Yunzhen Liu, Yudong Lu