73018-10-7Relevant articles and documents
Highly uniform self-assembled monolayers of silver nanospheres for the sensitive and quantitative detection of glutathione by SERS
Chen, Yi,Huang, Feixiang,Jiang, Cailing,Jiang, Li
supporting information, p. 10436 - 10445 (2021/08/09)
The homeostasis and imbalance of glutathione (GSH), an important antioxidant in organisms, are one of the key signals that reflect the health of organisms. In this paper, a novel SERS sensing platform based on Ag film@Si that self-assembled using silver nanospheres was proposed, which was used for the highly sensitive and selective detection of GSH. With the aid of an oil/water/oil three-phase system, the nano-silver film was self-assembled and finally deposited on silicon wafers. The heterobifunctional crosslinking agentN-succinimidyl-3-(2-pyridyldithio)propionate (SPDP), which contains pyridine rings and disulfide bonds, was involved in the exchange reaction between the sulfhydryl groups and disulfide bonds. With the addition of GSH, the breakage of disulfide bonds was promoted, thereby enhancing the SERS signal of SPDP. GSH can be detected sensitively by detecting the changes in the SPDP signal. The detection limit of GSH is 10 nM, and the method is still highly stable when the external environment is serum or other more complex environments.
Washington Red (WR) dyes and their imaging applications
Chen, Wei,Xian, Ming
, p. 149 - 163 (2020/06/08)
Near-infrared (NIR) fluorescent dyes with optimum photophysical properties are highly useful for bioimaging in living systems, but such dyes are still rare. Recently, our laboratory developed a unique class of NIR fluorescent dyes with high quantum yields and large Stokes shifts. These dyes, named as Washington Red (WR), were found to be useful scaffolds to develop NIR fluorescent imaging probes upon easy modifications on their phenolic hydroxyl group. In this chapter, we provide a comprehensive summary of this work, including the design and synthesis of WR dyes, their photophysical properties studies, and applications in developing NIR probes to image H2S in cells. The detailed experimental protocols are described.
Hydropersulfides: H-Atom Transfer Agents Par Excellence
Chauvin, Jean-Philippe R.,Griesser, Markus,Pratt, Derek A.
supporting information, p. 6484 - 6493 (2017/09/12)
Hydropersulfides (RSSH) are formed endogenously via the reaction of the gaseous biotransmitter hydrogen sulfide (H2S) and disulfides (RSSR) and/or sulfenic acids (RSOH). RSSH have been investigated for their ability to store H2S in vivo and as a line of defense against oxidative stress, from which it is clear that RSSH are much more reactive to two-electron oxidants than thiols. Herein we describe the results of our investigations into the H-atom transfer chemistry of RSSH, contrasting it with the well-known H-atom transfer chemistry of thiols. In fact, RSSH are excellent H-atom donors to alkyl (k ～ 5 × 108 M-1 s-1), alkoxyl (k ～ 1 × 109 M-1 s-1), peroxyl (k ～ 2 × 106 M-1 s-1), and thiyl (k > 1 × 1010 M-1 s-1) radicals, besting thiols by as little as 1 order and as much as 4 orders of magnitude. The inherently high reactivity of RSSH to H-atom transfer is based largely on thermodynamic factors; the weak RSS-H bond dissociation enthalpy (～70 kcal/mol) and the associated high stability of the perthiyl radical make the foregoing reactions exothermic by 15-34 kcal/mol. Of particular relevance in the context of oxidative stress is the reactivity of RSSH to peroxyl radicals, where favorable thermodynamics are bolstered by a secondary orbital interaction in the transition state of the formal H-atom transfer that drives the inherent reactivity of RSSH to match that of α-tocopherol (α-TOH), nature's premier radical-trapping antioxidant. Significantly, the reactivity of RSSH eclipses that of α-TOH in H-bond-accepting media because of their low H-bond acidity (α2H ～ 0.1). This affords RSSH a unique versatility compared to other highly reactive radical-trapping antioxidants (e.g., phenols, diarylamines, hydroxylamines, sulfenic acids), which tend to have high H-bond acidities. Moreover, the perthiyl radicals that result are highly persistent under autoxidation conditions and undergo very rapid dimerization (k = 5 × 109 M-1 s-1) in lieu of reacting with O2 or autoxidizable substrates.
