We　report　a　simple,　efficient　and　versatile　method　for　assembling　metal　oxide　nanomaterial-graphene　core-shell　structures.　An　ultraviolet　photodetector　fabricated　from　the　ZnO　nanoparticle-graphene　core-shell　structures　showed　high　responsivity　and　fast　transient　response,　which　are　attributed　to　the　improved　carrier　transport　efficiency　arising　from　graphene　encapsulation.