A Rationally Designed Upconversion Nanoprobe for in Vivo Detection of Hydroxyl Radical

Abstract

The detection of •OH in live organisms is crucial to the understanding of its physiological and pathological roles; while this is too challenging because of the extremely low concentration and high reactivity of the species in the body. Herein, we report the rational design and fabrication of an NIR-light excited luminescence resonance energy transfer-based nanoprobe, which for the first time realizes the in vivo detection of •OH. The nanoprobe is composed of two moieties: upconversion nanoparticles with sandwich structure and bared surface as the energy donor; and mOG, a modified azo dye with tunable light absorption, as both the energy acceptor and the •OH recognizing ligand. The as-constructed nanoprobe exhibited ultrahigh sensitivity (with the quantification limit down to 1.2 femtomolar, several orders of magnitude lower than that of most previous •OH probes), good biocompatibility, and specificity. It was successfully used for monitoring [•OH] levels in live cells and tissues.

Fluorescent nanoprobes for sensing and imaging of metal ions: Recent advances and future perspectives

“…Upconversion nanoparticles (UCNPs), a class of rare-earth ion-doped nanoluminophores with excitation wavelengths in the near-infrared (NIR) region [140-146], have been emerging as the ideal nanoprobes for selective sensing and imaging of metal ions both in vitro and in vivo [147,148], due to their unique properties including tunable multicolor emission, exceptional photostability, deep tissue penetration and suppression of autofluorescence, and low in vitro and in vivo toxicity [35,149-151]. Therefore much progress has been made in their controlled synthesis, surface engineering, and applications in biomedicine [152-155].…”

Current Advances in Lanthanide‐Doped Upconversion Nanostructures for Detection and Bioapplication

“…As previously mentioned, UCNPs with large anti‐Stokes shift, weak background interference, and no photobleaching are suitable to detect some target species, such as pH,148, 149 temperature,150, 151 metal ions,68, 152, 153, 154 anion,155 free radicals,156 biological molecules,24, 41, 113, 157, 158 and so on 159, 160. Most cases of detection are based on LRET process with a few exceptional cases.…”

Fabrication of a LRET-based upconverting hybrid nanocomposite for turn-on sensing of H2O2and glucose

“…43,56 However, to our knowledge, using the combination of bared UCNPs and metal nanoparticle for bioassay remains largely unexplored. the limited LRET efficiency.…”