Rare earth ions enhanced near infrared fluorescence of Ag₂S quantum dots for the detection of fluoride ions in living cells

Abstract

In this work, a novel phenomenon was discovered that the fluorescence intensity of silver sulfide quantum dots (AgS QDs) could be enhanced in the presence of rare earth ions through aggregation-induced emission (AIE). Based on the strong coordination between rare earth ions and F, a facile and label-free strategy was developed for the detection of F in living cells. AgS QDs were synthesized using 3-mercaptopropionic acid as sulfur source and stabilizer in aqueous solution. The near infrared (NIR) emitting QDs exhibited excellent photostalilty, high quantum yield and low toxic. Interestingly, the fluorescence intensity of QDs was obviously enhanced upon the addition of various rare earth ions, especially in the presence of Gd. The AIE mechanism was proved via the TEM, zeta potential and dynamic light scattering analysis. Moreover, the coordination between rare earth ions and F could lead to the quenching of fluorescence QDs due to the weakening the AIE. Based on these findings, we developed a highly sensitive and selective method for detection of F. The label-free NIR fluorescence probe was successfully used for F bioimaging in live cells.

Haemostatic Nanoparticles-Derived Bioactivity of from Selaginella tamariscina Carbonisata

“…The slit widths of EX and EM were 10 nm and 10 nm, respectively. In order to minimise the reabsorption effect, A c and A q remained below below 0.05 [41]. NP QY was calculated according to the following formula:…”

Tumor Microenvironment‐Activated NIR‐II Nanotheranostic System for Precise Diagnosis and Treatment of Peritoneal Metastasis

“…As illustrated in Scheme , the preparation of FEAD1 includes two main processes. First, bait ions, Er 3+ , are introduced to trigger cross‐linking between histidine imidazole groups in Fmoc‐His and carboxyl groups in the MPA‐Ag 2 S QDs, by metal coordination and electrostatic interactions . Second, a typical chemodrug, doxorubicin (DOX), and the NIR absorber A1094 act as initiators to drive multi‐component self‐assembly based on multiple intermolecular interactions, i.e., hydrophobic interactions, π–π stacking, and electrostatic forces .…”

Biosensors Based on Advanced Sulfur-Containing Nanomaterials

“…Functionalization of sulfur-containing quantum dots (especially, sulfide quantum dots) with different stabilizing agents to form surface groups can enhance their hydrophilicity and interaction ability with other biomolecules [ 115 , 118 , 119 , 120 ]. The low toxicity of sulfur-containing quantum dots made them suitable to be used for sensing in cells or living bodies [ 83 , 121 , 122 , 123 ].…”

“…Sulfide quantum dots, such as Ag 2 S quantum dots, displayed fluorescence emission in NIR window, therefore they have been used to establish biosensors. Moreover, Ding et al [ 123 ] have fabricated a NIR biosensor for detecting F − in living cells based on NIR emitting Ag 2 S quantum dots. The fluorescence intensity of Ag 2 S quantum dots enhanced when various rare earth ions were added.…”