A Dual-Emission Fluorescent Nanocomplex of Gold-Cluster-Decorated Silica Particles for Live Cell Imaging of Highly Reactive Oxygen Species

Abstract

A novel nanocomplex displaying single-excitation and dual-emission fluorescent properties has been developed through a crown-like assembly of dye-encapsulated silica particles decorated with satellite AuNCs for live cell imaging of highly reactive oxygen species (hROS), including •OH, ClO(-) and ONOO(-). The design of this nanocomplex is based on our new finding that the strong fluorescence of AuNCs can be sensitively and selectively quenched by these hROS. The nanocomplex is demonstrated to have excellent biocompatibility, high intracellular delivery efficiency, and stability for long-time observations. The results reveal that the nanocomplex provides a sensitive sensor for rapid imaging of hROS signaling with high selectivity and contrast.

DNA-stabilized, fluorescent, metal nanoclusters for biosensor development

“…They were able to detect as little as 200 nM cholesterol [133]. Recently, Chu and co-workers detected highly oxidative species inside cells using AuNCs decorated on silica nanoparticles [134].…”

Bovine serum albumin-stabilized gold nanoclusters as a fluorescent probe for determination of ferrous ion in cerebrospinal fluids via the Fenton reaction

“…BSA-AuNCs exhibit strong fluorescence, arising from intraband transitions of free electrons of the BSAAuNCs [24]. In the presence of •OH, which is produced by Fenton reaction between Fe 2+ and H 2 O 2 , the fluorescence intensity of the BSA-AuNCs can decrease significantly, attributable to the oxidation of Au(0) to Au(I) by •OH [20]. Thus it is possible for us to fabricate a facile means with BSA-AuNCs for the detection of Fe 2+ ion in the presence of H 2 O 2 .…”

“…It is proven that the fluorescence of BSAAuNCs is quenched by hydroxyl radical (•OH) [20], which is produced in the Fenton reaction between Fe 2+ and H 2 O 2 . Then Fe 2+ can be determined by the amount of generated •OH through fluorescent quenching.…”

Protein-gold clusters-capped mesoporous silica nanoparticles for high drug loading, autonomous gemcitabine/doxorubicin co-delivery, and in-vivo tumor imaging

“…[67] This nuclei targeting is also the origin of several drug delivery studies, [68][69][70][71] such as DOX delivery via AuNC@BSA combined with two-photon imaging. [72] AuNCs were also covalently grafted on non-porous silica NPs for cytosol imaging and reactive oxygen species detection via the quenching of the gold fluorescence, [73] however, AuNCs were not combined with MSN.…”