A label-free electrochemical immunosensor based on encapsulated signal molecules in mesoporous silica-coated gold nanorods for ultrasensitive assay of procalcitonin

A gold nanoparticle (AuNP)-capped mesoporous silica nanosphere (MSN)-based intracellular drug delivery system (PR-AuNPs-MSN) for the photoinduced controlled release of an anticancer drug, paclitaxel, inside of human fibroblast and liver cells was synthesized and characterized. We found that the mesopores of MSN could be efficiently capped by the photoresponsive AuNPs without leaking the toxic drug, paclitaxel, inside of live human cells. This "zero premature release" characteristic is of importance for delivery of toxic drugs in chemotherapy. Furthermore, we demonstrated that the cargo-release property of this PR-AuNPs-MSN system could be easily controlled by low-power photoirradiation under biocompatible and physiological conditions. We envision that our results would play a significant role in designing new generations of carrier materials for intracellular delivery of a variety of hydrophobic toxic drugs.

Mesoporous silica-coated gold nanorods (Au@SiO(2)) are developed as a promising and versatile theranostic platform for cancer treatment. Intracellular localization of Au@SiO(2) is visualized through two-photon imaging. With doxorubicin hydrochloride loaded, Au@SiO(2)-DOX show two light-mediated therapeutic modes: low power density laser-triggered drug release for chemotherapy, and high power density laser-induced hyperthermia, which suggest the potential for in-vivo applications. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.