A novel gold-nanocluster-based fluorescent sensor for detection of sodium 2-mercaptoethanesulfonate

Gold nanoclusters (Au NCs) are widely used in various types of detections due to their unique fluorescence properties. However, there are rare reports on enhanced fluorescence sensors for drug molecules. Here, we report a novel strategy for detection of sodium 2-mercaptoethanesulfonate (MES) by using a fluorescence-enhanced histidine stabilized Au NCs (His-Au NCs) probe. This fluorescence probe showed excellent selectivity and sensitivity towards MES. Furthermore, we have demonstrated that the fluorescence enhancement of His-Au NCs was attributed to ligand exchange with MES by Fourier Transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The feasibility of practical applications of this probe was further investigated by sensing the MES content in Mesna injection (Uromitexan).

Functionalized Polyisobutylene and Liquid/Liquid Separations as a Method for Scavenging Transition Metals from Homogeneously Catalyzed Reactions

Ethanedithiol-functionalized polyisobutylene was prepared in one step by a photoinitiated thiol-ene “click” reaction starting from ethanedithiol and polyisobutylene (PIB). The functionalized oligomer product was then used as a soluble sequestrant for transition metals. This PIB-bound thioether-thiol ligand is phase selectively soluble in alkanes and it quantitatively sequesters common transition metals like Cu2+ and Pd2+ into an alkane phase, separating them from polar solvents in a biphasic liquid/liquid separation. The chelating thioether-thiol ligand was also successfully used to remove Cu and Pd transition metal catalyst residues from products in crude reaction mixtures in both azide/alkyne click reactions and cross-coupling reactions using a liquid/liquid extraction. Separation efficiencies exceeding 95% and in many cases 99% were achieved.

Different Effects of His-Au NCs and MES-Au NCs on the Propagation of Pseudorabies Virus

In a previous work, gold nanoclusters (Au NCs) are found to inactivate RNA virus, but the effect of surface modification of Au NCs on its proliferation is still largely unknown. Here, the effect of surface modification of Au NCs on the proliferation of pseudorabies virus (PRV) by synthesizing two types of gold clusters with different surface modification, histidine stabilized Au NCs (His-Au NCs) and mercaptoethane sulfonate and histidine stabilized Au NCs (MES-Au NCs), is investigated. His-Au NCs rather than MES-Au NCs could strongly inhibit the proliferation of PRV, as indicated by the results of plaque assay, confocal microscopic analysis, Western blot assay, and quantitative real-time polymerase chain reaction (PCR) assay. Further study reveals that His-Au NCs perform the function via blockage of the viral replication process rather than the processes of attachment, penetration, or release. Additionally, His-Au NCs are found to be mainly localized to nucleus, while MES-Au NCs are strictly distributed in cytoplasm, which may explain why His-Au NCs can suppress the proliferation of PRV, but not MES-Au NCs. These results demonstrate that surface modification plays a key role in the antiviral effects of Au NCs and a potential antiviral agent can be developed by changing the Au NC surface modification.

New synthetic strategy targeting well-defined α,ω-telechelic polymethylenes with hetero bi-/tri-functionalities via polyhomologation of ylides initiated by new organic boranes based on catecholborane and post functionalization

Diverse well-defined α,ω-telechelic polymethylenes with hetero bi-/tri-functionalities were synthesized by a tandem strategy combining polyhomologation with post functionalization using end-capping reagents and esterification.