Elaboration of hollow mesoporous organosilica nanospheres of various sizes

Abstract

Hollow mesoporous organosilica (HMO) nanoparticles with a controlled core cavity and a mesoporous organosilica shell are elaborated using coupled hard and soft templating approaches. A dense silica hard template is first synthesized following the classical Stöber sol–gel protocol. The hybrid silica shell is then deposited through the co-condensation of an organosilane precursor with surfactant. HMO-NPs are obtained after the removal of the hard and soft templates. In this study, we demonstrate that this strategy can be applied to synthesize HMO-NPs of different sizes. We present a multiscale approach for a step-by-step characterization of synthesis stages, the structural organization of the PMO shell, and its properties. Particular emphasis is placed on the removal of the silica hard template step. A protocol is proposed to assess the efficiency of the etching process and estimate any remaining silica using infrared spectroscopy. Finally, from the perspective of potential medical applications, preliminary tests on endocytosis and biocompatibility are presented and yield promising results.