Similarly, the exfoliated 1L-MoS2 was firstly transferred onto a Si/SiO2 wafer followed by a monolayer of graphene (MoS2/G). Then, the whole wafter with MoS2/G heterostructure was dip-coated with a thin BPO layer in a same concentration by the same method. The laserinduced functionalization was carried out on the top of the upper graphene layer using same parameters as the preparation of F-G/MoS2.