Thiols-Induced Rapid Photoluminescent Enhancement of Glutathione-Capped Gold Nanoparticles for Intracellular Thiols Imaging Applications

Abstract

The rapid detection and imaging of intracellular thiols is of great importance during the occurrence and development of some chronic diseases. Here we demonstrate the rapid thiols-induced photoluminescence (PL) enhancement of the low luminescent glutathione (GSH) stabilized Au nanoparticles, AuGSH (low). The dynamic PL investigation reveals that the PL enhancement fits a first-order reaction model. The X-ray photoelectron spectroscopic and mass spectroscopic results indicate that AuGSH (low) are mainly comprised of "thiols-insufficient" Au species and the additional thiols can efficiently attach to the "unsaturated" surface of Au nanoparticles, accompanied by significant PL enhancement. The noncytotoxic AuGSH (low) probe can be successfully applied for imaging of intracellular thiols. Generally, this work illustrates the great prospects of facile-prepared AuGSH (low) as a candidate for thiols labeling and imaging.

Gold nanoparticles as sensitive optical probes

“…For example, glutathione is used as a ligand to prepare fluorescent Au NPs in the absence or presence of another reducing agent (e.g., carbon monoxide). 24,25 In the top-down approach, nonfluorescent Au NPs are prepared first. Etching ligands such as thiolates, polymers and DNAs are then added to etch the nonfluorescent Au NPs to form fluorescent Au NPs.…”

Surface Regulation Towards Stimuli‐Responsive Luminescence of Ultrasmall Thiolated Gold Nanoparticles for Ratiometric Imaging

“…However, the 600 nm‐emitting MPS‐AuNPs did not show significant luminescence enhancement upon addition of extra MPS ligands (Figure S11, Supporting Information), which might be due to high occupied MPS on the surface of AuNPs. Unlike the MPS molecule, the adding of glutathione (GSH), an important biothiol and electron‐rich molecule, induced great enhancement on the luminescence of 600 nm‐emitting MPS‐AuNPs, which was attributed to the strong electron‐donating ability of the GSH molecules . The results further demonstrated that the EDA molecules absorbed on the surface of the high surface‐ligand covered MPS‐AuNPs could donate the delocalized electron density to the AuNPs, resulted in the enhancement of the high‐energy emission at 600 nm.…”

Nanotechnology‐Based Strategies for Early Diagnosis of Central Nervous System Disorders

“…[ 49 ] In addition, multivalent CNS cations such as zinc, copper, and iron have been investigated as biomarkers for AD. [ 50 ] The net surface charge of Aβ is negative, whereas multivalent cations are positively charged. Thus, it is believed that the electrostatic interactions between the negatively charged protein and cations can further accelerate the oligomerization and fibrillation process.…”

“…The gelsolin and cellular prion protein (PrP C ) are naturally existing proteins used as bioreceptors for targeting AD biomarkers, including the Aβ 1‐40 and Aβ 1‐42 . [ 167 ] In addition to these, antibodies and aptamers are also considered bioreceptors that revealed excellent binding affinities toward Aβ peptides, Aβ oligomers, p‐tau181, and CNAs (miRNAs, cell‐free nucleic acids (cfNAs)) [50b,161] . This bioreceptor provided an excellent binding similar to an antibody by an antigen and hence exhibited a strong electrochemical transduction response.…”