▎ 摘　　要

To explore the new iodine labeling method of nanomaterials, graphene oxide (GO) was labeled by 131I with AgI nanoparticles. As a control, GO was also labeled by 131I with chloramine-T method. The stability of the two 131I labeling materials, viz. [131I]AgI-GO and [131I]I-GO was evaluated. The results show that [131I]AgI-GO is very stable in inorganic environment such as PBS and saline. However, it is not stable enough in serum. The instability of [131I]AgI-GO in serum can be attributed to the higher affinity of Ag to S of thiol group in cysteine than iodine ions and much more chance of interaction between thiol group and [131I]AgI nanoparticles on two-dimensional GO than in three-dimensional nanomaterials.