The preparation of dual functionalized nanoparticles is generally provided along with their application. The dual functionalized nanoparticles provide dual targeting and can effectively pass the blood brain barrier and target brain tissue. The dual targeted and dual responsive nanoparticles are functionalized to include at least two different ligands that are capable of transport across the blood brain barrier. The nanoparticles can be prepared from polymeric materials that can be biocompatible, provide long circulation life in a body, and be successfully ligated to both functionalities by use of acid-sensitive and/or redox potential-sensitive bonds for delivery across the blood brain barrier and delivery of a payload to brain tissue.
