Bimetal–organic-frameworks-derived yolk–shell-structured porous Co2P/ZnO@PC/CNTs hybrids for highly sensitive non-enzymatic detection of superoxide anion released from living cells

2016 ◽  
Vol 52 (84) ◽  
pp. 12442-12445 ◽  
Author(s):  
Min-Qiang Wang ◽  
Cui Ye ◽  
Shu-Juan Bao ◽  
Yan Zhang ◽  
Mao-Wen Xu ◽  
...  
Keyword(s):  
Superoxide Anion ◽  
Living Cells ◽  
Electrochemical Sensing ◽  
Superoxide Anions ◽  
Highly Active ◽  
Highly Sensitive ◽  
Enzymatic Detection ◽  
Organic Framework

Bimetal-organic framework derived yolk–shell–structured porous Co2P/ZnO@PC/CNTs were used as highly active electrocatalysts for electrochemical sensing of superoxide anions.

Fluorescence ratio imaging of dynamic intracellular ionic signals

1988 ◽  
Vol 46 ◽  
pp. 42-43
Author(s):  
R. Y. Tsien ◽  
A. Minta ◽  
M. Poenie ◽  
J.P.Y. Kao ◽  
A. Harootunian
Keyword(s):  
Binding Sites ◽  
Living Cells ◽  
Molecular Engineering ◽  
Ph Indicators ◽  
Highly Sensitive ◽  
Fluorescence Ratio Imaging ◽  
Ratio Imaging ◽  
Technical Advances ◽  
Indicator Dyes ◽  
Fluorescein Dyes

Recent technical advances now enable the continuous imaging of important ionic signals inside individual living cells with micron spatial resolution and subsecond time resolution. This methodology relies on the molecular engineering of indicator dyes whose fluorescence is strong and highly sensitive to ions such as Ca2+, H+, or Na+, or Mg2+. The Ca2+ indicators, exemplified by fura-2 and indo-1, derive their high affinity (Kd near 200 nM) and selectivity for Ca2+ to a versatile tetracarboxylate binding site3 modeled on and isosteric with the well known chelator EGTA. The most commonly used pH indicators are fluorescein dyes (such as BCECF) modified to adjust their pKa's and improve their retention inside cells. Na+ indicators are crown ethers with cavity sizes chosen to select Na+ over K+: Mg2+ indicators use tricarboxylate binding sites truncated from those of the Ca2+ chelators, resulting in a more compact arrangement of carboxylates to suit the smaller ion.

A Three-Dimensional Tetraphenylethylene-Based Fluorescence Covalent Organic Framework for Molecular Recognition

2020 ◽  
Author(s):  
Junxia Ren ◽  
Yaozu Liu ◽  
Xin Zhu ◽  
Yangyang Pan ◽  
Yujie Wang ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Fluorescence Probe ◽  
Three Dimensional ◽  
Hazardous Substances ◽  
Covalent Organic Framework ◽  
Highly Sensitive ◽  
Volatile Organic ◽  
Polycyclic Aromatic ◽  
Better Than ◽  
Organic Framework

<p><a></a><a></a><a></a><a></a><a></a><a></a><a></a><a>The development of highly-sensitive recognition of </a><a></a><a></a><a></a><a></a><a>hazardous </a>chemicals, such as volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs), is of significant importance because of their widespread social concerns related to environment and human health. Here, we report a three-dimensional (3D) covalent organic framework (COF, termed JUC-555) bearing tetraphenylethylene (TPE) side chains as an aggregation-induced emission (AIE) fluorescence probe for sensitive molecular recognition.<a></a><a> </a>Due to the rotational restriction of TPE rotors in highly interpenetrated framework after inclusion of dimethylformamide (DMF), JUC-555 shows impressive AIE-based strong fluorescence. Meanwhile, owing to the large pore size (11.4 Å) and suitable intermolecular distance of aligned TPE (7.2 Å) in JUC-555, the obtained material demonstrates an excellent performance in the molecular recognition of hazardous chemicals, e.g., nitroaromatic explosives, PAHs, and even thiophene compounds, via a fluorescent quenching mechanism. The quenching constant (<i>K</i><sub>SV</sub>) is two orders of magnitude better than those of other fluorescence-based porous materials reported to date. This research thus opens 3D functionalized COFs as a promising identification tool for environmentally hazardous substances.</p>

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