A facile method is described to prepare pH-sensitive and self-fluorescent drug delivery systems using mesoporous silica nanoparticles and PAMAM dendrimers, providing a general route to develop multifunctional and biocompatible platforms, which integrated increasing the number of reaction sites, retaining drug molecules, controlling drug delivery behaviour and fluorescent imaging into one carrier system, for biomedical imaging diagnosis and simultaneous therapy for lesion sites such as cancers. (C) 2014 Elsevier B.V. All rights reserved.