A benzothiazole-based dual reaction site fluorescent probe for the selective detection of hydrazine in water and live cells

As hydrazine is an environmental pollutant and highly toxic to living organisms, selective and rapid detection is highly needed for the benefit of living organisms as well as the environment. Here, we first introduced a novel benzothiazole conjugated methyldicyanovinyl coumarin probe BTC, with dual recognition sites for hydrazine detection. The incorporation of the methyldicyanovinyl group into the benzocoumarin fluorophore increased the electrophilicity of the lactone ring of the probe BTC facilitating the nucleophilic attack of hydrazine and rapid (within 1 min, low detection limit = 1.7 nM) turn-on sky blue fluorescence with 700-fold fluorescence intensity enhancement was observed via hydrazine-induced lactone ring-opening followed by selective cleavage of the dicyanovinyl group. According to the literature, dicyanovinyl group assisted lactone ring opening has revealed the possibility of hydrazine recognition with a large Stokes shift (140 nm) and a high fluorescence quantum yield (0.67). Here, the DFT study and practical applications of the probe BTC in different water samples have been presented. The probe BTC was also successfully applied for the detection of hydrazine in the vapor phase using paper strips and in live MDA-MB 231 cells.

Indicator displacement assays: from concept to recent developments

Overcoming the synthetic burden related to covalently connected receptors with appropriate indicators for sensing various analytes via an indicator spacer receptor (ISR) approach, the indicator displacement assay (IDA) seems to be a very sophisticated and versatile supramolecular sensing paradigm, and it has taken the phenomenon of molecular recognition to the next level in the realm of host-guest chemistry. Due to the unavailability of a comprehensive report on what has been done in the last decade in relation to IDAs, we decided to set down this account illustrating diverse indicator displacement assays (IDAs) in detail from the concept stage to recent developments relating to the detection of cationic, anionic, and neutral analytes. The authors conclude this account with future perspectives and highlight the limitations and challenges relating to IDAs which need to be overcome in order to realize the full potential of this popular sensing phenomenon. While we were finalizing our account for publication, a tutorial review by the research groups of Anslyn, Sessler, and Sun was published, which focuses mainly on diverse aspects of the chemistry related to IDAs. As can be seen, our review, besides discussing various basic IDA concepts, has a vast collection of information published in the past decade and hence, hopefully, will be very informative for the supramolecular community. We believe that this work will offer new insights for the construction of novel sensors operating through the IDA approach.

A cysteine-selective fluorescent probe for monitoring stress response cysteine fluctuations

Rare studies provided evidence for the real-time monitoring of stress response cysteine fluctuations. Here, we have successfully designed and synthesized a cysteine-selective fluorescent probe 1 to monitor stress response Cys fluctuations, providing visual evidence of Hg2+ regulated cysteine fluctuations for the first time, which may open a new way to help researchers to reveal the mechanism of heavy metal ion poisoning.

Encapsulation of oxime acetylcholinesterase reactivators: influence of physiological conditions on the stability of oxime-cucurbit[7]uril complexes

The influence of physiological conditions on the host–guest chemistry of oxime acetylcholinesterase reactivators with cucurbit[7]urile was investigated to increase their effectiveness for the treatment of organophosphate intoxication.

Heparin sensing based on multisite-binding induced highly ordered perylene nanoaggregates

Heparin sensing based on highly ordered perylene nanoaggregates with ultra-low fluorescence and the use of host–guest complexes to improve the sensitivity.